Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This in turn is enabling controlled chemical patterning from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
Nanoimaging Applications
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Single-Molecule Biological Imaging
Shelley Claridge, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Measuring and controlling optical interactions at the molecular scale: Photoswitching and interference
Yue Bing Zheng,1,2,3 John L Payton,4 Bala K Pathem,1,2,3 Choong-Heui Chung,1,3 Sarawut Cheunkar,4 Yang Yang,1,3 Lasse Jensen,4 and Paul S. Weiss,1,2,3
1. California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
2. Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA
3. Department of Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
4. Department of Chemistry, The Pennsylvania State University, University Park, PA 16802, United States
Light-molecule interactions are at the core of optical operations and analyses of molecular and supramolecular devices. We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures and to serve as test structures for measuring single or bundled molecules. Optical interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to switch reversibly isolated single molecules and assemblies on surfaces and can be probed by scanning tunneling microscopy and surface-enhanced Raman spectroscopy. We quantitatively compare experimental measurements to theoretical calculations. Lastly, we discuss our initial efforts in learning to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles, in which we find and control vibrational interference.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This in turn is enabling controlled chemical patterning from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
Imaging and single-molecule vibrational spectroscopy of cubanethiolate on Au{111}
John C Thomas,1,2 J. Nathan Hohman,1,2 Harsharn Auluck,1,2 Moonhee Kim,1,2 Justin R Griffiths,3 Ronny Priefer,3 and Paul S. Weiss,1,2
1. California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
2. Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
3. Department of Chemistry, Niagara University, Niagara, NY 14109, United States
We have measured scanning tunneling microscope (STM) images and inelastic tunneling spectra (IETS) of isolated cubanethiolates immobilized on Au{111} at 4K in extreme high vacuum (XHV). Cubane is the most compact, stable carbon cage molecule, and its tunneling spectra give vibrational information, and structural detail of thiolate binding at the Au surface. Images of isolated cubanethiolate species reveal modest mobility at 4K. Point spectra of adsorbed cubanethiolate were obtained and correlated with calculated spectra at the B3LYP/6-31G level of theory. Spectroscopic modes were assigned and fit. Molecular motion at substrate step edges was also observed.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Precise Assemblies, Clusters, Superatoms, and Cluster-Assembled Materials
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Precise clusters offer a new set of building blocks with unique properties that can be leveraged both individually and in materials in which their coupling can be controlled by choice of linker, dimensionality, and structure. Initial measurements in both of these worlds have been made. Isolated adsorbed or tethered clusters are probed with low-temperature scanning tunneling microscopy and spectroscopy. Even closely related elements behave differently on identical substrates. Surprising spectral variations are found for repeated measurements of single isolated, tethered clusters. In periodic solids, precise clusters joined by linkers can be measured experimentally and treated theoretically with excellent agreement, in part due to the relatively weak coupling of the clusters. This coupling can be controlled and exploited to produce materials with tailored properties. Some of the rules of thumb for predicting these properties are being developed through these initial studies and the limit to which they can be applied is being explored.
Precise Assembly and Precise Measurements of Molecules and Devices for Energy Conversion
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity. We are able to measure the photoconduction and photoreaction of isolated species in well-defined environments.
Measuring Optical Interactions at the Molecular Scale in Precise Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures with controlled environments and dimensionality, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules and assemblies. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. We are particularly interested in the interactions of photons with the precisely assembled structures. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. The measured results of photoexcitation include photoconductivity and regioselective reaction. We anticipate applying this method to optimize molecules and materials for energy conversion and storage. Related imaging spectroscopies developed give access to the cooperative action of assembled molecular motors and the identification and orientations of parts of molecules such as amyloid-forming oligopeptides.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Local Spectroscopies for Subnanometer Spatial Resolution Chemical Imaging
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Precise Assemblies, Clusters, Superatoms, and Cluster-Assembled Materials
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Precise clusters offer a new set of building blocks with unique properties that can be leveraged both individually and in materials in which their coupling can be controlled by choice of linker, dimensionality, and structure. Initial measurements in both of these worlds have been made. Isolated adsorbed or tethered clusters are probed with low-temperature scanning tunneling microscopy and spectroscopy. Even closely related elements behave differently on identical substrates. Surprising spectral variations are found for repeated measurements of single isolated, tethered clusters. In periodic solids, precise clusters joined by linkers can be measured experimentally and treated theoretically with excellent agreement, in part due to the relatively weak coupling of the clusters. This coupling can be controlled and exploited to produce materials with tailored properties. Some of the rules of thumb for predicting these properties are being developed through these initial studies and the limit to which they can be applied is being explored.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Precise Assemblies, Clusters, Superatoms, and Cluster-Assembled Materials
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Precise clusters offer a new set of building blocks with unique properties that can be leveraged both individually and in materials in which their coupling can be controlled by choice of linker, dimensionality, and structure. Initial measurements in both of these worlds have been made. Isolated adsorbed or tethered clusters are probed with low-temperature scanning tunneling microscopy and spectroscopy. Even closely related elements behave differently on identical substrates. Surprising spectral variations are found for repeated measurements of single isolated, tethered clusters. In periodic solids, precise clusters joined by linkers can be measured experimentally and treated theoretically with excellent agreement, in part due to the relatively weak coupling of the clusters. This coupling can be controlled and exploited to produce materials with tailored properties. Some of the rules of thumb for predicting these properties are being developed through these initial studies and the limit to which they can be applied is being explored.
Controlling Functional Molecules and Precise Assemblies: Cooperativity and Interference
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
For some time, we have been placing single functional molecules in controlled environments, driving them with a variety of stimuli, and measuring their function. Now, we are creating precise assemblies of functional molecules and trying to drive them together. In so doing, we are getting our first glimpses of the rules of cooperativity and interference at the nanoscale. I will discuss both our assembly strategies, and our first measurements of these assembled functional systems. Assemblies are created by designing interactions between molecules and processing the matrices in which they are to be held, both to make room for the functional assemblies and to bring functional components into proximity. Combinations of experiment and theory are applied in order to understand supramolecular interactions and cooperative function. While most proximate functional molecules studied to date have been found to interfere with each other, we describe early successes in getting cooperative action as well as strategies to go further into this new area.
Controlling Functional Molecules and Precise Assemblies: Cooperativity and Interference
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
For some time, we have been placing single functional molecules in controlled environments, driving them with a variety of stimuli, and measuring their function. Now, we are creating precise assemblies of functional molecules and trying to drive them together. In so doing, we are getting our first glimpses of the rules of cooperativity and interference at the nanoscale. I will discuss both our assembly strategies, and our first measurements of these assembled functional systems. Assemblies are created by designing interactions between molecules and processing the matrices in which they are to be held, both to make room for the functional assemblies and to bring functional components into proximity. Combinations of experiment and theory are applied in order to understand supramolecular interactions and cooperative function. While most proximate functional molecules studied to date have been found to interfere with each other, we describe early successes in getting cooperative action as well as strategies to go further into this new area.
Design, Control, and Measurement of Molecular Assemblies
Bala Pathem, California NanoSystems Institute and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces [1]. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies [2]. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies [3]. This in turn is enabling controlled chemical patterning from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
References:
Since we have learned to measure the precise structures, environments, interactions, and functions of molecules at the nanoscale, we are now learning to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measurements of single or coupled molecules. Hierarchical patterning enables simultaneous control at many levels, all the way from the macroscale through the microscale, ultimately to the subnanometer scale. Interactions within and between molecules can be designed, directed, measured, understood, and exploited. We examine how these interactions influence chemistry, dynamics, structure, electronic function, and other properties. Such interactions can be used to advantage to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve improve synthetic systems at all scales. We are also using these strategies to control and to understand interactions, function, and structures of biological systems. We see opportunities to make inroads into refractory problems in biology and medicine, and will discuss our first results and strategies in these areas.
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces [1]. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies [2]. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies [3]. This in turn is enabling controlled chemical patterning from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
References:
Over the Horizon in Nanomedicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Analyzing STM Images and Simultaneously Recorded Polarizability Maps
Tawny Lim, Nen Huynh, and Jonathan Siegel, California NanoSystems Institute, Institute of Pure and Applied Mathematics, and Department of Mathematics, UCLA, Los Angeles, CA 90095, USA
Heterogeneity and Single Molecules in Medicine: Looking over the Horizon
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA, Monday 29 - Wednesday 29 August 2012
For some time, we have been placing single functional molecules in controlled environments, driving them with a variety of stimuli, and measuring their function. Now, we are creating precise assemblies of functional molecules and trying to drive them together. In so doing, we are getting our first glimpses of the rules of cooperativity and interference at the nanoscale. I will discuss both our assembly strategies, and our first measurements of these assembled functional systems. Assemblies are created by designing interactions between molecules and processing the matrices in which they are to be held, both to make room for the functional assemblies and to bring functional components into proximity. Combinations of experiment and theory are applied in order to understand supramolecular interactions and cooperative function. While most proximate functional molecules studied to date have been found to interfere with each other, we describe early successes in getting cooperative action as well as strategies to go further into this new area.
Hydrogen-Bonding Networks in Self-Assembled Monolayers
Jeffrey J. Schwartz,a,b Jian Shang (尚鉴),c Jing Liu (刘婧),c Jing Xin (金鑫),c Paul S. Weiss,a,d,e Kai Wu (吴凯)c
a) California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
b) Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
c) College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
d) Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
e) Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
Single-Domain Cobalt Nanoparticles Synthesized and Deposited for Nuclear Spin Detection
Hua Zheng,a,b Yuxi Zhao,b,c Jeffrey J. Schwartz,b,d and Paul S. Weissb,c,e
Paul S. Weiss
aDept. of Chemistry, Fudan University, Shanghai, 200433, P. R. China
bCalifornia NanoSystems Institute, cDept. of Chemistry and Biochemistry, dDept. of Physics and Astronomy, and eDept. of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
Beneath and Between: Structural, Functional, and Spectroscopic Measurements of Buried Interfaces and Interactions
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. These advances, in turn, are enabling controlled chemical patterning from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
For some time, we have been placing single functional molecules in controlled environments, driving them with a variety of stimuli, and measuring their function. Now, we are creating precise assemblies of functional molecules and trying to drive them together. In so doing, we are getting our first glimpses of the rules of cooperativity and interference at the nanoscale. I will discuss both our assembly strategies, and our first measurements of these assembled functional systems. Assemblies are created by designing interactions between molecules and processing the matrices in which they are to be held, both to make room for the functional assemblies and to bring functional components into proximity. Combinations of experiment and theory are applied in order to understand supramolecular interactions and cooperative function. While most proximate functional molecules studied to date have been found to interfere with each other, we describe early successes in getting cooperative action as well as strategies to go further into this new area.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
For some time, we have been placing single functional molecules in controlled environments, driving them with a variety of stimuli, and measuring their function. Now, we are creating precise assemblies of functional molecules and trying to drive them together. In so doing, we are getting our first glimpses of the rules of cooperativity and interference at the nanoscale. I will discuss both our assembly strategies, and our first measurements of these assembled functional systems. Assemblies are created by designing interactions between molecules and processing the matrices in which they are to be held, both to make room for the functional assemblies and to bring functional components into proximity. Combinations of experiment and theory are applied in order to understand supramolecular interactions and cooperative function. While most proximate functional molecules studied to date have been found to interfere with each other, we describe early successes in getting cooperative action as well as strategies to go further into this new area.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This in turn is enabling controlled chemical patterning from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Exploring and Controlling the Nanoscale World
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
The Ultimate Limits of Miniaturization: Exploring and Controlling the Nanoscale World in Science, Engineering, and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Since we have learned to measure the precise structures, environments, interactions, and functions of molecules at the nanoscale, we are now learning to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measurements of single or coupled molecules. Hierarchical patterning enables simultaneous control at many levels, all the way from the macroscale through the microscale, ultimately to the subnanometer scale. Interactions within and between molecules can be designed, directed, measured, understood, and exploited. We examine how these interactions influence chemistry, dynamics, structure, electronic function, and other properties. Such interactions can be used to advantage to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve improve synthetic systems at all scales. We are also using these strategies to control and to understand interactions, function, and structures of biological systems. I will discuss upcoming opportunities to make inroads into refractory problems in biology and medicine, and will discuss our first results and strategies in these areas.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
The properties of both biological and inorganic materials can be tailored by precise modulation of structures over length scales from <1-100 nm. I will discuss two classes of experiments at biological–solid-state interfaces. First, the phenomenal specificity of DNA hybridization is used to direct the formation of discrete nanocrystal structures, analogous to nanocrystal molecules. Physical properties of nanocrystal molecules can be understood and controlled via properties analogous to bond length and reactivity in small molecules. Importantly, inorganic nanocrystals can be used to quantify the behavior of the biomolecular linker, shedding light on biological processes such as DNA repair using techniques including small-angle X-ray scattering. Second, I will discuss experiments aimed at understanding protein structure at the single-molecule level, without the requirement for crystallization. These experiments bring the sub-nanometer resolving power of scanning tunneling microscopy to bear on structural biology, starting with peptides that form beta sheets, one of the fundamental building blocks of protein structure.
The properties of both biological and inorganic materials can be tailored by precise modulation of structures over length scales from <1-100 nm. I will discuss two classes of experiments at biological–solid-state interfaces. First, the phenomenal specificity of DNA hybridization is used to direct the formation of discrete nanocrystal structures, analogous to nanocrystal molecules. Physical properties of nanocrystal molecules can be understood and controlled via properties analogous to bond length and reactivity in small molecules. Importantly, inorganic nanocrystals can be used to quantify the behavior of the biomolecular linker, shedding light on biological processes such as DNA repair using techniques including small-angle X-ray scattering. Second, I will discuss experiments aimed at understanding protein structure at the single-molecule level, without the requirement for crystallization. These experiments bring the sub-nanometer resolving power of scanning tunneling microscopy to bear on structural biology, starting with peptides that form beta sheets, one of the fundamental building blocks of protein structure.
The properties of both biological and inorganic materials can be tailored by precise modulation of structures over length scales from <1-100 nm. I will discuss two classes of experiments at biological–solid-state interfaces. First, the phenomenal specificity of DNA hybridization is used to direct the formation of discrete nanocrystal structures, analogous to nanocrystal molecules. Physical properties of nanocrystal molecules can be understood and controlled via properties analogous to bond length and reactivity in small molecules. Importantly, inorganic nanocrystals can be used to quantify the behavior of the biomolecular linker, shedding light on biological processes such as DNA repair using techniques including small-angle X-ray scattering. Second, I will discuss experiments aimed at understanding protein structure at the single-molecule level, without the requirement for crystallization. These experiments bring the sub-nanometer resolving power of scanning tunneling microscopy to bear on structural biology, starting with peptides that form beta sheets, one of the fundamental building blocks of protein structure.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
The properties of both biological and inorganic materials can be tailored by precise modulation of structures over length scales from <1-100 nm. I will discuss two classes of experiments at biological–solid-state interfaces. First, the phenomenal specificity of DNA hybridization is used to direct the formation of discrete nanocrystal structures, analogous to nanocrystal molecules. Physical properties of nanocrystal molecules can be understood and controlled via properties analogous to bond length and reactivity in small molecules. Importantly, inorganic nanocrystals can be used to quantify the behavior of the biomolecular linker, shedding light on biological processes such as DNA repair using techniques including small-angle X-ray scattering. Second, I will discuss experiments aimed at understanding protein structure at the single-molecule level, without the requirement for crystallization. These experiments bring the sub-nanometer resolving power of scanning tunneling microscopy to bear on structural biology, starting with peptides that form beta sheets, one of the fundamental building blocks of protein structure.
Designing, Measuring, and Controlling Molecular and Supramolecular Devices
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
The properties of both biological and inorganic materials can be tailored by precise modulation of structures over length scales from <1-100 nm. I will discuss two classes of experiments at biological–solid-state interfaces. First, the phenomenal specificity of DNA hybridization is used to direct the formation of discrete nanocrystal structures, analogous to nanocrystal molecules. Physical properties of nanocrystal molecules can be understood and controlled via properties analogous to bond length and reactivity in small molecules. Importantly, inorganic nanocrystals can be used to quantify the behavior of the biomolecular linker, shedding light on biological processes such as DNA repair using techniques including small-angle X-ray scattering. Second, I will discuss experiments aimed at understanding protein structure at the single-molecule level, without the requirement for crystallization. These experiments bring the sub-nanometer resolving power of scanning tunneling microscopy to bear on structural biology, starting with peptides that form beta sheets, one of the fundamental building blocks of protein structure.
Neuroscience at the Nanoscale at UCLA: Dynamic Nanoscale Chemical Mapping of the Brain
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Controlling and Measuring Optical Interactions at the Molecular Scale in Atomically Precise Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures with controlled environments and dimensionality, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules and assemblies. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. We are particularly interested in the interactions of photons with precisely assembled structures. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. The measured results of photoexcitation include photoconductivity and regioselective reaction. We anticipate applying this method to optimize molecules and materials for energy conversion and storage. Related imaging spectroscopies we have developed give access to the cooperative action of assembled molecular motors and the identification and orientations of parts of molecules such as amyloid-forming oligopeptides. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. We are now applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while measuring the environment, interactions, and dynamics of molecular probes designed for this purpose.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
The properties of both biological and inorganic materials can be tailored by precise modulation of structures over length scales from <1-100 nm. I will discuss two classes of experiments at biological–solid-state interfaces. First, the phenomenal specificity of DNA hybridization is used to direct the formation of discrete nanocrystal structures, analogous to nanocrystal molecules. Physical properties of nanocrystal molecules can be understood and controlled via properties analogous to bond length and reactivity in small molecules. Importantly, inorganic nanocrystals can be used to quantify the behavior of the biomolecular linker, shedding light on biological processes such as DNA repair using techniques including small-angle X-ray scattering. Second, I will discuss experiments aimed at understanding protein structure at the single-molecule level, without the requirement for crystallization. These experiments bring the sub-nanometer resolving power of scanning tunneling microscopy to bear on structural biology, starting with peptides that form beta sheets, one of the fundamental building blocks of protein structure.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces. The monolayer matrices and the inserted molecules can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This in turn is enabling hierarchically controlled chemical patterning and selective functionalization from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
Understanding interactions and function in precise supramolecular assemblies helps elucidate the rules of working at the ultimate limit of miniaturization. We design and assemble new functional materials controlled at the single-molecule and single-assembly levels. Critical to gaining this understanding has been recording statistically significant distributions of functional measurements at the single-molecule scale. I will discuss how we develop and apply new tools to design, to measure, and to understand interactions within and between molecules at unprecedented scales. Such interactions can be used to control the self-assembly of molecules into nanostructures and to stabilize their function. We apply the assembly strategies that we have developed for flat surfaces to curved and faceted substrates, while developing new tools to measure the environment, interactions, and dynamics of precise molecular assemblies.
Bottom-up assembly of functional molecules provides a promising approach towards new materials and devices working at the ultimate limit of miniaturization. Measuring and controlling the physical, chemical, and electronic interactions between and within molecules is essential to directing assembly and optimizing function. I will discuss our progress towards creating precise assemblies of molecules on atomically flat surfaces and using them as test structures to elucidate the correlation between interactions and function of molecules. We apply molecular design, tailored syntheses, and intermolecular interactions to direct molecules into desired positions to form precise assemblies. New tools have been developed and applied to measure structure, interactions, dynamics, and function of molecules and assemblies at unprecedented scales. These measurements combined with theoretical calculations guide us in designing, directing, and exploiting interactions to assemble increasingly complex nanostructures and to control their function. We also apply the assembly strategies that we have learned from atomically flat surfaces to curved and faceted substrates, while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Bottom-up assembly of functional molecules provides a promising approach towards new materials and devices working at the ultimate limit of miniaturization. Measuring and controlling the physical, chemical, and electronic interactions between and within molecules is essential to directing assembly and optimizing function. I will discuss our progress towards creating precise assemblies of molecules on atomically flat surfaces and using them as test structures to elucidate the correlation between interactions and function of molecules. We apply molecular design, tailored syntheses, and intermolecular interactions to direct molecules into desired positions to form precise assemblies. New tools have been developed and applied to measure structure, interactions, dynamics, and function of molecules and assemblies at unprecedented scales. These measurements combined with theoretical calculations guide us in designing, directing, and exploiting interactions to assemble increasingly complex nanostructures and to control their function. We also apply the assembly strategies that we have learned from atomically flat surfaces to curved and faceted substrates, while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Biological systems have vividly demonstrated how precisely controlled optical interactions at the molecular scale enable complex functions such as human vision and plant photosynthesis. Inspired by nature, we aim to design, direct, measure, understand, and exploit optical interactions within and between molecules for the ever smaller and more functional devices. This talk will cover our recent progress towards this goal. We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create atomically precise assemblies that serve as test structures for measuring optical interactions at the unprecedented scales. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. The measured results of photoexcitation include photoisomerization and regioselective reaction. In an effort towards mimicking biological systems where molecules act cooperatively, we find both interferences and cooperativity in photoswitching of precise assemblies of synthetic molecules. We are also applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Bottom-up assembly of functional molecules provides a promising approach towards new materials and devices working at the ultimate limit of miniaturization. Measuring and controlling the physical, chemical, and electronic interactions between and within molecules is essential to directing assembly and optimizing function. I will discuss our progress towards creating precise assemblies of molecules on atomically flat surfaces and using them as test structures to elucidate the correlation between interactions and function of molecules. We apply molecular design, tailored syntheses, and intermolecular interactions to direct molecules into desired positions to form precise assemblies. New tools have been developed and applied to measure structure, interactions, dynamics, and function of molecules and assemblies at unprecedented scales. These measurements combined with theoretical calculations guide us in designing, directing, and exploiting interactions to assemble increasingly complex nanostructures and to control their function. We also apply the assembly strategies that we have learned from atomically flat surfaces to curved and faceted substrates, while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules.1-3 Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules.4 The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles.5 We discuss our initial efforts in this area, in which we find both interferences and cooperativity.3
References
1. From the Bottom Up: Dimensional Control and Characterization in Molecular Monolayers. S. A. Claridge, W.-S. Liao, J. C. Thomas, Y. Zhao, H. Cao, S. Cheunkar, A. C. Serino, A. M. Andrews, and P. S. Weiss, Chemical Society Reviews 42 (2013), in press. DOI: 10.1039/C2CS35365B.
2. Molecular Switches and Motors on Surfaces. B. K. Pathem, S. A. Claridge, Y. B. Zheng, and P. S. Weiss, Annual Review of Physical Chemistry 64, 605 (2013), in press. DOI: 10.1146/ANNUREV-PHYSCHEM-040412-110045.
3. Photoresponsive Molecules in Well-Defined Nanoscale Environments. Y. B. Zheng, B. K. Pathem, J. N. Hohman, J. C. Thomas, M. H. Kim, and P. S. Weiss, Advanced Materials 25, 302 (2013).
4. Polarizabilities of Adsorbed and Assembled Molecules: Measuring the Conductance through Buried Contacts. A. M. Moore, S. Yeganeh, Y. Yao, S. A. Claridge, J. M. Tour, M. A. Ratner, and P. S. Weiss, ACS Nano 4, 7630 (2010).
5. Molecular, Supramolecular, and Macromolecular Motors and Artificial Muscles. D. B. Li, R. Baughman, T. J. Huang, J. F. Stoddart, and P. S. Weiss, MRS Bulletin 34, 671 (2009).
Biological systems have vividly demonstrated how precisely controlled optical interactions at the molecular scale enable complex functions such as human vision and plant photosynthesis. Inspired by nature, we aim to design, direct, measure, understand, and exploit optical interactions within and between molecules for the ever smaller and more functional devices. This talk will cover our recent progress towards this goal. We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create atomically precise assemblies that serve as test structures for measuring optical interactions at the unprecedented scales. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. The measured results of photoexcitation include photoisomerization and regioselective reaction. In an effort towards mimicking biological systems where molecules act cooperatively, we find both interferences and cooperativity in photoswitching of precise assemblies of synthetic molecules. We are also applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Biological systems have vividly demonstrated how precisely controlled optical interactions at the molecular scale enable complex functions such as human vision and plant photosynthesis. Inspired by nature, we aim to design, direct, measure, understand, and exploit optical interactions within and between molecules for the ever smaller and more functional devices. This talk will cover our recent progress towards this goal. We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create atomically precise assemblies that serve as test structures for measuring optical interactions at the unprecedented scales. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. The measured results of photoexcitation include photoisomerization and regioselective reaction. In an effort towards mimicking biological systems where molecules act cooperatively, we find both interferences and cooperativity in photoswitching of precise assemblies of synthetic molecules. We are also applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules [1-3]. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules [4]. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles [5]. We discuss our initial efforts in this area, in which we find both interferences and cooperativity [3].
References
[1] From the Bottom Up: Dimensional Control and Characterization in Molecular Monolayers. S. A. Claridge, W.-S. Liao, J. C. Thomas, Y. Zhao, H. Cao, S. Cheunkar, A. C. Serino, A. M. Andrews, and P. S. Weiss, Chemical Society Reviews 42 (2013), in press. DOI: 10.1039/C2CS35365B.
[2] Molecular Switches and Motors on Surfaces. B. K. Pathem, S. A. Claridge, Y. B. Zheng, and P. S. Weiss, Annual Review of Physical Chemistry 64, 605 (2013), in press. DOI: 10.1146/ANNUREV-PHYSCHEM-040412-110045.
[3] Photoresponsive Molecules in Well-Defined Nanoscale Environments. Y. B. Zheng, B. K. Pathem, J. N. Hohman, J. C. Thomas, M. H. Kim, and P. S. Weiss, Advanced Materials 25, 302 (2013).
[4] Polarizabilities of Adsorbed and Assembled Molecules: Measuring the Conductance through Buried Contacts. A. M. Moore, S. Yeganeh, Y. Yao, S. A. Claridge, J. M. Tour, M. A. Ratner, and P. S. Weiss, ACS Nano 4, 7630 (2010).
[5] Molecular, Supramolecular, and Macromolecular Motors and Artificial Muscles. D. B. Li, R. Baughman, T. J. Huang, J. F. Stoddart, and P. S. Weiss, MRS Bulletin 34, 671 (2009).
Biological systems have vividly demonstrated how precisely controlled optical interactions at the molecular scale enable complex functions such as human vision and plant photosynthesis. Inspired by nature, we aim to design, direct, measure, understand, and exploit optical interactions within and between molecules for the ever smaller and more functional devices for applications in nanoelectromechanical systems, energy, and medicine. This talk will cover our recent progress towards this goal. We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create atomically precise assemblies that serve as test structures for measuring optical interactions at the unprecedented scales. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. In an effort towards mimicking biological systems where molecules act cooperatively to link the molecular-scale behavior to macroscopic world and to achieve complex functions, we find both interferences and cooperativity in precise assemblies of artificial molecular machines. We are also applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while developing new tools to measure the environment, interactions, and dynamics of precise assemblies.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
I Hate Averaging
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Nanoprisms as Excitable Substrates for Scanning Probe Microscopes
Garrett Wadsworth, California NanoSystems Institute and Department of Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Defining Yourself and Your Work
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Exploring and Controlling the Nanoscale World: From the World's Smallest Motors Working Cooperatively to the Brain
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
The nanoscale revolution began when we developed the "eyes" to see structures at the nanoscale. From there, we developed the abilities to measure structure, function, dynamics, and spectra at these scales simultaneously, so that the extraordinary heterogeneity of the nanoscale world started to become apparent. With this new knowledge, we have learned strategies to place atoms and molecules with extraordinary precision and to explore the ultimate limits of miniaturization. These advances have, in turn, led us to ask the question "How does Nature do it?" across many fields.
Recent measurements have demonstrated that we can get atomically precise synthetic assemblies to operate cooperatively.1 By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve the fabrication, operation, and efficiency of synthetic systems at all scales.
Now, advances in chemical patterning, nanofabrication, imaging, and other areas are being applied to study the brain, the most complex structure we know. Current technologies explore the brain at relatively low resolution or record the activity of one or a few neurons with much greater precision. By developing new technologies and measurement platforms based on recent advances and investments in nanoscience and other fields, we hope to understand the function of the brain both at the nanoscale at which neurons and other cells interact and through parallel measurements, at the circuit level of thousands to millions of neurons.2 By developing the means to measure and to interact with neural circuits, we hope to understand learning and memory. Understanding the differences between healthy function and dysfunction in the case of disease and animal models of disease ultimately targets the accelerated development of treatments and cures.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Developing Nanoscale Measurements for the Brain
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Exploring and Controlling the Nanoscale World: From the World's Smallest Motors Working Cooperatively to the Brain
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Nanoscale Optical Interactions in Precise Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures with controlled environments and dimensionality, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules and assemblies. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. We are particularly interested in the interactions of photons with precisely assembled structures. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. The measured results of photoexcitation include photoconductivity and regioselective reaction. We anticipate applying this method to optimize molecules and materials for energy conversion and storage. Related imaging spectroscopies we have developed give access to the cooperative action of assembled molecular motors and the identification and orientations of parts of molecules such as amyloid-forming oligopeptides. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. We are now applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while measuring the environment, interactions, and dynamics of molecular probes designed for this purpose.
Supervised Segmentation of Domain Boundaries in STM Images of Self-Assembled Molecule Layers
Dan Zhou, Matt Vollmer, Daniel Lander, and Rodrigo Rios, IPAM and California NanoSystems Institute, UCLA, Los Angeles, CA 90095, USA
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
The California NanoSystems Institute
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Nanoscale Optical Interactions in Precise Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Keywords: Self-assembly, scanning tunneling microscopy, molecular devices.
Abstract: We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures with controlled environments and dimensionality, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules and assemblies [1,2]. We have developed and applied new tools based on the scanning tunneling microscope (STM) to measure structure, function, and spectra simultaneously. We are particularly interested in the interactions of photons with precisely assembled structures. Much previous work in this area has been limited by the absorption of light by the STM tip, resulting in heating and making quantitative measurements difficult. We have overcome this difficulty by coupling light evanescently into the tunneling junction using specially prepared substrates and a new set of STMs. The measured results of photoexcitation include photoconductivity and regioselective reaction [3]. We anticipate applying this method to optimize molecules and materials for energy conversion and storage. Related imaging spectroscopies we have developed give access to the cooperative action of assembled molecular motors and the identification and orientations of parts of molecules such as amyloid-forming oligopeptides. Complementary far-field measurements enable statistically significant optical measurements of function, dynamics, and chemical environment. We are now applying the assembly strategies that we have developed for flat surfaces to curved and faceted substrates while measuring the environment, interactions, and dynamics of molecular probes designed for this purpose [4].
References:
[1] Y.B. Zheng, B.K. Pathem, J.N. Hohman, J.C. Thomas, M.H. Kim and P.S. Weiss, Adv. Matl. Vol. 25 (2013), p. 302.
[2] S.A. Claridge, W.-S. Liao, J.C. Thomas, Y. Zhao, H. Cao, S. Cheunkar, A.C. Serino, A.M. Andrews and P.S. Weiss, Chem. Soc. Rev. Vol. 42 (2013), p. 2725.
[3] M.H. Kim, J.N. Hohman, Y. Cao, K.N. Houk, H. Ma, A.K.-Y. Jen and P.S. Weiss, Science Vol. 331 (2011), p. 1315.
[4] Y.B. Zheng, J.L. Payton, T.-B. Song, B.K. Pathem, Y. Zhao, H. Ma, Y. Yang, L. Jensen, A.K.-Y. Jen and P.S. Weiss, Nano Lett. Vol. 12 (2012), p. 5362.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Motion and Dynamics across Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Nature has extraordinarily efficient means to convert chemical to mechanical energy and motion. No synthetic or hybrid systems come close to such efficiencies at any scale. Through design of precisely assembled synthetic systems and close coupling to theory and simulation, we hope to elucidate the roles of key nanoscale features that enable high efficiency. To date, most systems studied interfere when functional molecules and assemblies are put in proximity. These results point to the need for greater control in spacing and interactions at the chemical and assembly scales. First examples of cooperative function have been demonstrated in simple synthetic systems and will be discussed. Understanding the differences between our intuition, which is based on the macroscopic world, and the rules of nanoscale motion will be critical to further advances.
We are different at all scales and that is what makes us interesting and beautiful
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Communications and Controversies in Nanotechnology
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Exploring and Controlling the Atomic-Scale World
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095
Probing the Buried and Exposed Interface within Two-Dimensional Assembled Structures
John C. Thomas and Paul S. Weiss
California NanoSystems Institute
and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095
We have observed aligned dipoles forming two-dimensional plastic lattices in self-assembled monolayers of carboranethiols on Au{111}. We have used scanning tunneling microscopy (STM) and simultaneously acquired local barrier height images of 9,12-dicarba-closo-dodecaborane o-9-carboranethiol (O9) monolayers on Au{111} at 4K in extreme high vacuum to determine the local structures and dipole orientations within the monolayers. The molecular structure of O9 is that of a symmetric cage; a two-dimensional plastic lattice of aligned dipoles is formed through favorable intermolecular dipole-dipole interactions after chemisorption. Local barrier height images juxtaposed with the simultaneously recorded topography reveal directional dipole offsets within domains. New imaging analysis methods were used to overlay the multimodal data and determine molecular dipole orientations. We employ Monte Carlo simulations to model the dipole-dipole interactions, and to predict alignment at low temperature. We compare and contrast topographic and simultaneously acquired local barrier height images of 1,7-dicarba-closo-dodecaborane m-1-carboranethiol (M9) on Au{[111} in which the largest dipole is due to the sulfur-gold bond (as opposed to the cage) and is aligned to topographic maxima in STM images. We also use the STM to image peptide structure at the single-molecule scale in a model peptide that forms beta sheets, a structural motif common in protein misfolding diseases. We successfully differentiate between histidine and alanine amino acid residues, and further differentiate side chain orientations in individual histidine residues, by correlating features in STM images with energy-optimized models. Such measurements are a first step toward analyzing peptide and protein structures at the single-molecule level.
Difunctionalized Carboranes on Gold Surfaces
Olivia Irving, John C. Thomas, Harsharn Auluck, Jonny Dadras, Anastassia Alexandrova, and Paul S. Weiss, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA
Single-Molecule Optical Spectroscopy with Ångström-Scale Precision
Yuxi Zhao, Moonhee Kim, J. Nathan Hohman, Garrett A. Wadsworth, Jeffrey J. Schwartz, Paul S. Weiss
California NanoSystems Institute
and Departments of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095
Mapping Local Dipole Domains within Two-Dimensional Plastic Lattices
John C. Thomas, Jeffrey J. Schwartz, Harsharn S. Auluck, G. Tran; Jerome Gilles, Stan Osher, Chad A. Mirkin of Northwestern University, and Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 900
We have observed aligned dipoles forming two-dimensional plastic lattices in self-assembled monolayers of carboranethiols on Au{111}. We have used scanning tunneling microscopy (STM) and simultaneously acquired local barrier height images of 9,12-dicarba-closo-dodecaborane o-9-carboranethiol (O9) monolayers on Au{111} at 4K in extreme high vacuum to determine the local structures and dipole orientations within the monolayers. The molecular structure of O9 is that of a symmetric cage; a two-dimensional plastic lattice of aligned dipoles is formed through favorable intermolecular dipole-dipole interactions after chemisorption. Local barrier height images juxtaposed with the simultaneously recorded topography reveal directional dipole offsets within domains. New imaging analysis methods were used to overlay the multimodal data and determine molecular dipole orientations. We employ Monte Carlo simulations to model the dipole-dipole interactions, and to predict alignment at low temperature. We compare and contrast topographic and simultaneously acquired local barrier height images of 1,7-dicarba-closo-dodecaborane m-1-carboranethiol (M9) on Au{[111} in which the largest dipole is due to the sulfur-gold bond (as opposed to the cage) and is aligned to topographic maxima in STM images.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
The Ultimate Limits of Miniaturization: Exploring and Controlling the Nanoscale World in Science, Engineering, and Medicine
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Since we have learned to measure the precise structures, environments, interactions, and functions of molecules at the nanoscale, we are now learning to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measurements of single or coupled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited. We examine how these interactions influence chemistry, dynamics, structure, electronic function, and other properties. Such interactions can be used to advantage to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. By understanding interactions, function, and dynamics at the smallest possible scales, we hope to improve improve synthetic systems at all scales. We are also using these strategies to control and to understand interactions, function, and structures of biological systems. I will discuss upcoming opportunities to make inroads into refractory problems in biology and medicine, and will discuss our first results and approaches in these areas.
Visualizing Assembly of Differently Oriented Dipole Moments within Carboranethiols on Metal Substrates
Brandon Matthews, John C. Thomas, Harsharn S. Auluck, Logan A. Stewart, and Paul S. Weiss, California NanoSystems Institute and Department of Chemistry & Biochemistry, UCLA, Los Angeles, CA 90095, USA
Self-assembly, at the molecular level, is governed by interactions between the substrate and deposited molecules, and among neighboring and nearby molecules. Synthetic approaches in nanomaterials exploit these interactions at the single-molecule level, giving way to materials whose size, shape, and functionality are regulated by nanoscale interactions. Controlling the interactions between molecules, by choosing different surfactants, can lead to nanomaterials with tunable properties. Eutectic gallium-indium (EGaIn) was chosen to help determine the roles of these interactions at the nanoscale as supramolecular assembly can direct surface morphology in the liquid state. Particles of EGaIn were subjected to shear forces in solution via ultrasonication, with cage molecules m-1-carboranethiol (M1) or m-9-carboranethiol (M9) added as ligands to create self-assembled monolayers on the subsequently formed nanoparticles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the synthesized nanoparticles, including determinations of their shape, size, and oxide coverage. Preliminary results reveal correlations between particle shape and dipole orientation, as M1 produced faceted particles and M9 produced spherical particles. Carboranethiols enable the formation of stable monolayers that appear to dictate the resulting shape, size, and oxide coverage of EGaIn nanoparticles based on the individual dipole orientation. Polarization modulation infrared reflection absorption spectroscopy was also used to monitor varied dual codeposited carboranethiols on (flat) Au{111}, determining the molecule that dominated surface coverage in this competitive environment as a result of more favorably interacting dipoles.
Nanoscale Control and Measurements for Biology, Medicine, & Neuroscience
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We pattern the exposed chemical functionality of flat and surfaces with exquisite precision, from the submolecular to the macroscopic scales, so as to control the biological, chemical, and physical properties of these intefaces. We have developed this strategy to identify, to measure, and to mimic biochemical interactions. In synthetic systems, by recording many thousands of simultaneous structural, functional, and spectroscopic measurements of single molecules and assemblies, we have shown the importance of understanding the heterogeneity of structure, conformation, and environment that influence function. We are therefore developing structural and functional measurements for biological systems that eliminate the averaging intrinsic to methods such as diffraction and nmr. This will enable elucidation of the key roles of structure and conformation in biological function and access to structures are not arranged periodically.
Since important functions of the brain occur at the nanoscale, we anticipate that nanoscale tools can be developed to study and to interact with the brain and its component parts (see ACS Nano 7, 1850, 2013). In our initial work, we functionalized surfaces with isolated and tethered neurotransmitters. These capture surfaces are used to pull down membrane-associated proteins from the brain involved in neurotransmission as well as to select molecules to use as artificial receptors for in vivo measurements. The latter will be used to study chemical neurotransmission dynamically at high spatial resolution in many simultaneous parallel measurements. Parallel measurements of voltage activity are further along, such that several thousand measurements can now be made simultaneouly with a single multiplexed probe. Ultimately, the great heterogeneity of the brain will require many parallel and specific chemical and voltage measurements, so as to understand and to stimulate neural circuits. This understanding is the goal of the recently announced Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative in the United States. With an initial focus on technology development, there are great opportunities not only to study the brain, but also to develop diagnoses of and treatments for diseases of the brain. Understanding how neural circuits function and how they malfunction will be critical to these efforts.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 900
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Multimodal Nanoscale Imaging: Simultaneous Measurements of Structure, Function, and Spectra
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We have developed and applied a series of nanoscale analysis tools with which we are elucidating the origins of the heterogeneity of function across systems ranging from the smallest switches and motors, to components of solar cells, to biomolecular assemblies. By recording thousands of functional, dynamic, and/or spectroscopic measurements, we are able to obtain, to sort, and to understand statistically significant distributions of data on these systems. Along with our ability to "see" at these scales has come our ability to control the placement of chemical functionality from the subnanometer to the wafer scales, effectively adding the chemical dimension to nanolithography, so as to control the nanoscale interactions of materials with their chemical, physical, and biological environments.
New Dimensions in Patterning: Placement and Metrology of Chemical Functionality at All Scales
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We use molecular design, tailored syntheses, intermolecular interactions, and selective chemistry to direct molecules into desired positions to create nanostructures, to connect functional molecules to the outside world, and to serve as test structures for measuring single or bundled molecules. Interactions within and between molecules can be designed, directed, measured, understood, and exploited at unprecedented scales. Such interactions can be used to form precise molecular assemblies, nanostructures, and patterns, and to control and to stabilize function. We selectively test hypothesized mechanisms by varying molecular design, chemical environment, and measurement conditions to enable or to disable function and control using predictive and testable means. Critical to understanding these variations has been developing the means to make tens to hundreds of thousands of independent single-molecule measurements in order to develop sufficiently significant statistical distributions, while retaining the heterogeneity inherent in the measurements. We measure the electronic coupling of the molecules and substrates by measuring the polarizabilities of the connected functional molecules. The next step in such devices is to learn to assemble and to operate molecules together, both cooperatively and hierarchically, in analogy to biological muscles. We discuss our initial efforts in this area, in which we find both interferences and cooperativity.
Plasmonic Assemblies in One and Two Dimensions
Liane Slaughter, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
The surface plasmon resonance (SPR), the coherent oscillation of the conduction electrons, leads to intense absorption and scattering of light at frequencies satisfying the resonance condition determined by the size, shape, and spacings between noble metal nanoparticles (NPs). Growing and assembling nanostructures through wet chemistry yields a diversity of geometries. Strong coupling of the SPRs in NP assemblies provokes particular interest for structures with tunable optical properties that will benefit surface enhanced spectroscopies and optical computing, but the influence of the heterogeneity in real systems, which contrast idealized model systems, must be established one assembly at a time. Single particle microscopy and spectroscopy strategies reveal hidden relationships between the SPRs and the sizes, shapes, and arrangements of gold nanoparticles. The first part of my talk focuses on such relationships in quasi-linear assemblies of gold nanoparticles and their strongly coupled SPRs. Together, optical spectroscopy, scanning electron microscopy (SEM), and computational modeling of individual NPs and NP assemblies elucidate the resulting variety of SPRs of real assemblies.
The second part of my talk introduces developing work on quasi – two dimensional (2D) films of gold patterned through multi-step chemical lift-off lithography. Chemical lift-off lithography (CLL) is a low cost, high-throughput, subtractive patterning process where the protruding regions of a silicone elastomer stamp form chemical bonds with a preformed self-assembled monolayer (SAM) on gold. 'Lift-off' removes SAM molecules and a thin layer of gold onto the stamp, confirmed by elemental analysis of the stamp. Our multi-step CLL strategy produces nanometer, micron, and millimeter 2D features of possibly atomically thin gold over millimeter areas on flat insulating surfaces. An abundance of research has recently revealed unique and codependent optical and electronic properties in 2D atomically thin materials, especially in graphene, that can be tailored for metamaterials, optical circuits, and flexible electronics. Such properties include transparency, enhanced charge mobilities, and tunable bandgaps. Theoretical studies in the literature indicate that gold should be no exception, motivating us to probe the tunable optical and mechanical properties of the gold films we have produced.
Cooperative Function in Atomically Precise Nanoscale Assemblies
Paul S. Weiss, California NanoSystems Institute and Departments of Chemistry & Biochemistry and Materials Science & Engineering, UCLA, Los Angeles, CA 90095, USA
We place single molecules and larger groups into precisely controlled environments on surfaces. Monolayer matrices and inserted molecules and sub-assemblies can be designed so as to interact directly, to give stability or other properties to supramolecular assemblies. New families of molecules are being developed to yield even greater control and are enabling determination of the key design parameters of both the molecules and assemblies. This, in turn, is enabling hierarchically controlled chemical patterning and selective functionalization from the sub-nanometer to the centimeter scales. We are simultaneously developing a suite of metrology tools for these methods to give unprecedented information on the structures and properties of these assemblies.
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10 February 2014