Size- and Conformation-Specific Infrared Spectroscopy of Inter-and Intra-molecular Hydrogen Bonds

在化学学部物理化学项目中，普渡大学的t.s. Zwier教授将通过共振离子浸红外光谱和荧光浸红外光谱研究气相溶质-溶剂团簇的性质。这些研究涉及芳香族分子配合物的溶剂结构、生物分子的构象以及分子内h原子隧穿。要研究的几种体系包括水、甲醇、氯仿、氯化氢、甲烷和乙炔作为苯的溶剂。其他的研究集中在芳香氨基酸、它们的类似物和它们的含溶剂簇的构象，以及tropolone和它的几个衍生物，其中分子内氢键氢原子的h原子隧道反应起作用。涉及氢原子的分子内和分子间的弱相互作用被称为氢键力。这些在确定特别是大的生物分子的形状和构象以及分子形成簇聚集体方面起着重要作用。气相团簇为旨在理解氢键及其后果的理论提供了一个重要的试验场。由于水和醇的重要性和复杂性，人们对它们的气相团簇进行了大量的实验和理论研究。关于聚类属性随聚类大小变化的实验数据是稀疏的，需要用于测试理论模型。在缩合相中，溶质和溶剂之间的相互作用必须考虑溶质分子对溶剂结构的破坏以及溶质和溶质分子之间的特定位置的吸引和排斥作用。本研究将有助于更好地理解物理化学中的这些问题。

In this project in the Physical Chemistry Program of the Chemistry Division, Prof. T. S. Zwier of Purdue University will investigate the properties of gas-phase solute-solvent clusters by resonant ion-dip infrared spectroscopy and fluorescence-dip infrared spectroscopy. These studies concern the solvent structure in complexes involving aromatic molecules, conformers of biomolecules, and intramolecular H-atom tunneling. Among the several systems to be investigated are those of water, methyl alcohol, chloroform, hydrogen chloride, methane, and acetylene as the solvent species for benzene. Additional studies focus on the conformations of aromatic amino acids, their analogs, and their solvent-containing clusters, and on tropolone and several of its derivatives in which the H-atom tunneling reactions of the intramolecularly hydrogen-bonded hydrogen atoms play a role. Weak intramolecular and intermolecular interactions that involve a hydrogen atom are known as hydrogen-bonding forces. These play a significant role in defining the shape and conformation of especially large biomolecules and the association of molecules into cluster aggregates. Gas phase clusters provide an important testing ground for theories aimed at understanding the hydrogen bond and its consequences. The importance and complexity of water and the alcohols has prompted much experimental and theoretical work on their gas phase clusters. Experimental data on the variations of cluster properties with cluster size are sparse and are needed to test theoretical models. In the condensed phase the interaction between solute and solvent must consider both the disruption of the solvent's structure imposed by the solute molecule and site-specific attractions and repulsions between solvent and solute molecules. The present research will serve to obtain a better understanding of these problems in physical chemistry.