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| Research Domain：Synthetic Organic Chemistry, Asymmetric Synthesis |
Country：[CN] |
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1.Nucleophilic Catalysis in Selective Reactions
2.Asymmetric Synthesis based on Dynamic Chirality of Enolates
3.Synthesis of Biologically Active Natural Products |
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| Research Domain：complex molecular systems using ultrafast multi-dimensional infrared and optical methods. |
Country：[CN] |
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My research group studies complex molecular systems using ultrafast multi-dimensional infrared and optical methods. The properties of systems, such as molecular complexes, proteins, hydrogen bonding liquids, liquid crystals, or supercooled liquids depend on molecular level dynamics and intermolecular interactions. Bulk properties are frequently a very poor guide to understanding the molecular level details that determine the nature of a chemical process and its dynamics. Because molecules are small, molecular motions are inherently very fast. Recent advances in methodology developed in our labs make it possible for us to observe important processes as they occur. These measurements act like stop-action photography. To focus on a particular aspect of a time evolving system, we employ sequences of ultrashort pulses of light as the basis for non-linear methods such as ultrafast infrared multidimensional vibrational echoes, optical Kerr effect methods, and ultrafast transient absorption experiments.
Because of lack of space, I can only briefly mention the problems that we are investigating. I encourage you to look at our website, and contact me directly to discuss our research.
We are using ultrafast IR vibrational echo spectroscopy and other multi-dimensional IR methods, which we have pioneered, to study dynamics of molecular complexes, water confined on nm lengths scales with a variety of topologies, and proteins. We can probe the structural transformations of these systems. The methods are somewhat akin to multidimensional NMR, but they probe molecular structural evolution in real time on the relevant ultrafast time scales. We are examining the formation and dissociation of organic solute-solvent complexes and the isomerization molecules. We are obtaining direct information on how nanoscopic confinement of water changes its properties, a topic of great importance in chemistry, biology, geology, and materials. In proteins, we are using the vibrational echo methods to study dynamics and the relationship between dynamics and function. We are also developing and applying theory to these problems frequently in collaboration with top theoreticians.
We are studying dynamics in complex liquids, in particular liquid crystals and supercooled liquids and the glass transition using ultrafast optical heterodyne detected optical Kerr effect methods, We can follow processes from tens of femtoseconds to tens of microseconds and longer. Our ability to look over such a wide range of time scales is unprecedented. The change in molecular dynamics when a system undergoes a phase change is of fundamental and practical importance. We are developing detailed theory as the companion to the experiments.
We are studying photo-induced electron transfer and thermal equilibrium electron transfer using ultrafast absorption and multidimensional IR measurements to understand the processes leading to the generation of highly reactive chemical species. We want to understand the role of the solvent and the systems topology on electron transfer dynamics.
We are interested in the most basic questions: how do complex systems of interacting molecules behave at the molecular level? By using advanced experimental methods based on ultrafast laser technology and theory, we are obtaining fundamentally new views of chemical processes. |
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| Research Domain：invention of new atom and group transfer-type reaction processes. |
Country：[CN] |
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Research in my group is based broadly in methods development and chemical synthesis. Our early efforts have concentrated on the invention of new atom and group transfer-type reaction processes. The application of such methods to problems in natural product synthesis and chemical biology offers unique challenges in reaction design, and serves as the underlying motivation for our research. As one of our overarching goals, we wish to devise molecular systems for selective C–H amination and hydroxylation that integrate concepts in catalysis with those in molecular recognition. Such ideas are inspired by Nature and the metalloenzymes that perform hydrocarbon oxidation reactions with exquisite fidelity. A general interest in problems in molecular recognition and molecular design has stimulated our more recent work towards understanding the structure and physiology of ion channels. Altogether, projects in the group are intended to afford students expertise in synthetic chemistry while exposing them to problems in chemical kinetics and catalysis, physical organic and coordination chemistry, and structure design. Currently, we have four principal areas of concentration that include: • The elucidation of new reaction processes for carbon-heteroatom (C–N and C–O) bond formation through selective, metal-catalyzed C–H and s-bond functionalization. • Mechanistic analysis of Rh-promoted C–H amination; coordination chemistry and catalyst design. • Multi-step, asymmetric syntheses of complex, heterocyclic amine-derived natural products which include the manzacidins, tetrodotoxin, saxitoxin, aconitine, welwitindolinone, and agelastatin. • The development of guanidine toxin mimetics that function as tools for mapping the tertiary structure of the ion permeation pathway in voltage-gated Na+ and Ca2+ ion channel proteins. |
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| Research Domain：materials chemistry, solid state ,molecular electronics, novel chemical and biochemical sensors |
Country：[CN] |
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The research of my group interfaces with chemistry, physics, materials science, and biological and medical science. We are interested in solid state and soft biological materials that have well-defined atomic structures. Our work is in the areas of materials chemistry, solid state chemistry and physics, scanning probe microscopy, molecular electronics, novel chemical and biochemical sensors and nanomaterial based biological transporters and carriers for drug, DNA and protein delivery and novel therapeutics applications of nanomaterials. Specific projects include, (1) Nanotube synthesis including self-oriented multi-walled carbon nanotube arrays [Fan et al., Science, 1999], highly quality single-walled carbon nanotubes (SWNTs) by chemical vapor deposition (CVD) and their patterned growth on substrates [Kong et al., Nature, 1998; Soh et al., Appl. Phys. Lett., 1999;] and single particle patterning for nanotube growth [Javey et al., 2005, JACS]. (2) Fundamental electrical and electromechanical Properties of Nanotubes [Tombler, Nature, 2000; Cao, PRL, 2003 & 2004; Kong, PRL, 2001]. (3) Suspended nanotube synthesis and quantum transport [Cassell, JACS, 1999; Franklin, 2000; Cao, PRL, 2004]. (3) Nanotube Molecular Sensors and Biosensors. We are exploring nanotubes as novel electronic sensors for gases and biomolecules in solutions [Kong et al., Science, 2000; Chen, PNAS, 2003; Chen, JACS, 2004]. (3) Molecular electronics with ultrahigh performance [A. Javey et al., Nature Materials, 2002; A. Javey, Nature, 2003]. (4) Organic Electronics with Quasi 1D Electrodes [Qi, JACS, 2004]. (5) Intracellular Molecular Transporters and Near Infrared Nano-Therapy. We showed recently that nanotubes are transporters capable of shuttling various cargos (e.g. proteins and SiRNA) across cell membranes [Kam, JACS, 2004&2005]. We also developed a method to destruct cancer cells selectively by using nanotubes and near-infrared light [Kam, PNAS, 2005]. This is an exciting new area in nanobiotechnology in our group with many exciting opportunities ahead. (6) Germanium Nanowires. We are exploring novel synthesis, characterization and applications of semiconducting nanowires [Wang, Angew. Chemie, 2002 *2005; JACS, 2004&2005]. |
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| Research Domain：structure and properties of polymer catalysts, X-ray crystal structure of organic compounds and EXAFS and molecular mechanics of conducting polymers. |
Country：[CN] |
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Bai's research includes the structure and properties of polymer catalysts, X-ray crystal structure of organic compounds and EXAFS and molecular mechanics studies of conducting polymers. Since the mid 1980s, he has been involved in scanning probe microscopy. He has five patented series of microscopes, including the first atomic force microscope, scanning tunneling microscope and so on. Combining scanning probe microscopes with other techniques, he has systematically studied the surface structure and properties of organic and biological materials, and has made innovatory progress in the field of nano science and technology. He has won eight national and CAS awards and is the author of eight books and over 200 scientific papers. |
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| Research Domain：organic solids,organic crystals,high-temperature superconductors |
Country：[CN] |
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Since the 1970s, Zhu has been engaged in research on organic solids, one of the first scientists in China to start research in this field. Through his extensive studies, a series of new 1D and 2D organic conductors were discovered. He proposed and successfully introduced some structural characteristics of high-temperature superconductors for organic crystals, as a result of which, the first quasi-3D organic conductor was discovered. In connection with studies on organic ferromagnetism, dozens of organic compounds containing nitroxide radicals and magnetic LB films of nitroxide radicals were designed and prepared under his guidance. Based on these studies, he concluded that intermolecular interaction is the principal factor affecting the magnetic behavior of these molecular systems. The research results on the charge-transfer complexes based on C 60 , and the film structure of C 60 , C 70 as well as their derivatives have attracted great attention internationally. |
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| Research Domain：laser applications,superconducting magnets,superconducting microwave cavities,Molecular Reaction Dynamics |
Country：[CN] |
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Zhu taught in Yenching University, Peking University, Harbin Institute of Technology and Changsha Institute of Technology between 1951 and 1977. He taught physics for a long time and was engaged in the design of a nuclear power reactor and research on laser applications. From 1978 to 1981, he was in charge of building superconducting magnets and superconducting microwave cavities in the Institute of High Energy Physics . In 1981, he was in charge of the construction of the Molecular Reaction Dynamics Laboratory, Institute of Chemistry . Six large sets of high quality molecular beam facilities have been designed and built. Research on the photodissociation and photoionization of molecules and clusters has been performed on these facilities, and many valuable new results have been discovered. |
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| Research Domain：silicone chemistry,phenolic resin,triazine cross-linked new type heat-resistant polymers and cross-linked polyimides,heterocyclic ketene (aminals) |
Country：[CN] |
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Huang worked on silicone chemistry in the 1950s and phenolic resin in the 1960s. He synthesized phenolic resin for low-pressure fabrication and made his contributions to the heat protective materials for space technology. His creative work also covers the areas of triazine cross-linked new type heat-resistant polymers and cross-linked polyimides. Since the 1970s, he has studied heterocyclic ketene (aminals) and prepared more than 700 new compounds, whose biological activities are tested for screening drugs and agricultural chemicals. On the basis of phenolic resin, he studied the chemistry of calixarene, which could form host-quest inclusion complexes that might be used as model for enzyme mimics. He obtained significant results in chemical modification and the research of inclusion properties. |
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| Research Domain：Physical Chemistry |
Country：[CN] |
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Principal Research Interests:
The Chidsey group research interest is to build the chemical base for molecular electronics. To accomplish this, we synthesize the molecular and nanoscopic systems, build the analytial tools and develop the theoretical understanding with which to study electron transfer between electrodes and among redox species through insulating molecular bridges. Members of the group have synthesized several series of saturated and conjugated oligomers with which we have studied the fundamental aspects of electron tunneling through well-defined molecular bridges. The oligophenylenevinylene bridge of these molecules promotes rapid tunneling over remarkably long distances compared with other unsaturated and saturated bridges we have studied. For instance, starting in the activated complex, the tunneling rate between a gold electrode and an appended ferrocene through 3.5nm of an oligophenylenevinylene (OPV) bridge is 8 x 10 9 s-1 whereas the tunneling rate through an alkane bridge of the same length is expected to be slower than 1s -1.
To date our electron-tunneling studies have largely focused on what we casually denote as a "one-electrode" measurement with the molecular bridge connecting one electrode to a redox species which acts as a molecular capacitor to an ionically conducting solution. The other electrodes necessary to measure the tunneling conduction are remotely located in an electrochemical cell. We are currently embarked on a broad based effort to make conduction measurements with two electrodes, one on each end of a single molecule. We are also developing strategies to include one or more additional electrodes so that molecular circuits with electrical power gain can be assembled. This effort is leading us to develop nanostructured wiring schemes and self-assembly methods for the construction of whole circuits of wired molecules. We will be examining nanowires formed from doped silicon and other substances. This emerging effort in nanowiring will be greatly aided by the previous work in the Chidsey lab on the surface chemistry of silicon, particularly the self-assembly of complex molecular monolayers on silicon surfaces. |
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| Research Domain：understanding the fundamental interactions between molecules, both in isolation and in the complex environment of the cell. |
Country：[CN] |
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" The Robinson laboratory is interested in understanding the fundamental interactions between molecules, both in isolation and in the complex environment of the cell. We use our growing understanding to design proteins with more robust or novel properties and to engineer cellular systems for improved production or drug screening applications. To this end, we are investigating the determinants of protein folding and misfolding, on both an atomic and molecular level. We have developed several novel approaches to inhibiting protein misfolding and aggregation. Additionally, we are designing cellular systems for optimal expression of membrane proteins, and antibodies.Our approach uses techniques in molecular biology, genetic engineering, and biophysical chemistry to identify and study macromolecules at both an atomic and cellular level. Mechanistic modeling guides us in experimental design and analysis. We use both prokaryotic, or bacterial, systems as well as eukaryotic systems, such as yeast or mammalian cells. A major goal of this research is to establish a set of cellular systems that could express any protein of interest. The research in the laboratory has focus areas in protein stability, expression, and aggregation for biotechnology and biomedical applications. " |
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