International Collaboration in Chemistry: Structure and dynamics of amino acids adsorbed on coinage metal surfaces

在化学结构、动力学和机理计划的支持下，罗格斯大学化学和化学生物系的辛克教授和她的同事们正在使用热氦散射的高分辨率角度衍射和飞行时间分析来研究吸附氨基酸的结构、组装和低能分子表面振动。这一国际化学合作奖包括一位合作者，英国剑桥大学的斯蒂芬·J·詹金斯教授。他的工作得到了英国EPSRC的支持。丙氨酸、甘氨酸和脯氨酸在铸币金属表面的相互作用是本研究的重点。这些体系被认为是以羧酸形式吸附的，氨基可能发生质子化，也可能不发生质子化。在表面敏感的衍射测量中，有关吸附相的手性和可能的外消旋的信息将是显而易见的。用这种非破坏性的探头测定这些分子在表面上组装薄膜的实时动力学，将提供对分子间长程和短程相互作用的理解。在从低覆盖区到高覆盖区的转变中，离散振动模式和散射中心的有效质量的变化将阐明这些自组装薄膜中氢键的意义。低能振动光谱还可以确定共吸附氢能级对薄膜稳定性、组装动力学和表面扩散以及反应机理的影响。通过与剑桥大学詹金斯教授的团队合作，罗格斯大学的欣奇团队也将能够利用高分辨率低温扫描探头技术来研究氨基酸薄膜。国际合作还提供了强大的计算能力和对控制简单吸附氨基酸振动运动的多维势能表面的理解。一个共同的目标是成像、模拟和测量氨基酸薄膜中建立的氢键网络的动力学。这项研究将促进对吸附在表面的分子行为的理解。所获得的知识将对各种领域和应用产生影响，包括手性特定传感器、对映体选择性化学合成，以及可能具有更高生物兼容性的医疗植入材料。这项研究还对劳动力发展有相当大的好处，因为研究生和本科生以及博士后助理将从事丰富的跨学科研究经验，这需要各种实验技术以及理论和计算。国际交流方面将进一步扩大学生体验；罗格斯大学和剑桥大学集团的研究人员对合作实验室的长期访问将提供宝贵的经验，了解每个参与者所在机构以外的研究环境。

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.