With the support of the Chemical Structure, Dynamics and Mechanisms Program, Professor Hinch and her coworkers in the Department of Chemistry and Chemical Biology at Rutgers University are using high resolution angular diffraction and time of flight analysis of thermal helium scattering to investigate structure, assembly and low energy molecule surface vibrations of adsorbed amino acids. This International Collaboration in Chemistry award includes a collaborator, Professor Stephen J. Jenkins at Cambridge University in the United Kingdom. His work is supported by EPSRC in the United Kingdom. The interactions of alanine, glycine and proline adsorbates with coinage metal surfaces are the focus of this research. These systems are believed to adsorb as carboxylate species and the amino groups may or may not undergo protonation. Information about chirality and possible racemization of adsorbed phases will be evident in the surface sensitive diffraction measurements. The real time kinetics of film assembly of these molecules on the surfaces, determined with this non destructive probe, will provide an understanding of the long- and short- range intermolecular interactions. In transitioning from low to high coverage regimes, changes in the discrete vibrational modes, and the effective masses of the scattering centers, will elucidate the significance of hydrogen bonding in these self assembled films. The low energy vibrational spectra are also to determine the influence of coadsorbed hydrogen levels in film stability, kinetics of assembly and surface diffusion and reaction mechanisms. Through collaboration with Professor Jenkins' group at Cambridge University, the Hinch group at Rutgers will also be able to utilize high-resolution low-temperature scanning probe techniques for studies of amino acid films. The international collaboration also offers a powerful computational capability and understanding of the multi-dimensional potential energy surfaces governing vibrational motion in simple adsorbed amino acids. A mutual objective is to image, simulate, and measure the dynamics within hydrogen bonding networks established in the amino acid films.
This research will advance the understanding of the behavior of molecules adsorbed on surfaces. The knowledge obtained will implications for a variety of fields and applications, including chirally-specific sensors, enantioselective chemical synthesis, and possibly medical implant materials with improved biocompatibility. The research also has considerable workforce development benefits, as graduate and undergraduate students and post-doctoral associates will engage in a richly interdisciplinary research experience, which entails a variety of experimental techniques as well as theory and computation. The student experience will be further augmented by the international exchange aspects; extended visits by Rutgers and Cambridge group researchers to the partnering laboratory will provide invaluable experience with research environments beyond each participant's home institution.
