Weak Complexes Studied by Fourier Transform Microwave Spectroscopy

在这个项目中，弱结合分子配合物的结构将用高分辨率傅立叶变换微波光谱进行研究。该项目有六个组成部分：二元配合物包含1)二氧化硫分子，2)水分子，3)环丙烷分子和4)稀有气体原子；5)由三个单体分子组成的配合物；6)高温调查。该配合物将形成在超音速膨胀到真空的高压混合组分气体与中性载气。通过这种膨胀，络合物也被冷却到非常低的平移和旋转温度，大约比绝对零度高10度。这项工作将提供有关复合物的结构和内部运动（动力学）的信息，以及它们的电子特性，如电偶极矩。这些结果将提供关于分子间弱相互作用力和分子间势函数性质的基本信息，并将为开发和测试模型和理论提供所需的数据库，这些模型和理论可以指导化学家和生物化学家了解化合物如何相互作用并长成更大的簇。将要研究的团簇构成了一种介于稀气和冷凝相之间的物质状态，在冷凝和蒸发现象中起着至关重要的作用。弱分子间力在生物系统的结构和功能中也起着决定性的作用，其中生物分子的部分与其他部分相互作用，使其具有其功能的结构特征。在本研究中进行的分子间力的基础研究也将有助于建立数据库，在此基础上可以测试和校准预测新生化物质的理论。

In this project the structures of weakly bound molecular complexes are to be investigated by means of high resolution Fourier transform microwave spectroscopy. The project has six components: binary complexes containing 1) sulfur dioxide molecules, 2) water molecules, 3) cyclopropane molecules, and 4) rare gas atoms; 5) complexes formed by three monomer molecules; and 6) high temperature investigations. The complexes will be formed in the supersonic expansion into a vacuum of a high pressure mixture of component gases with a neutral carrier gas. Through this expansion the complexes are also cooled to very low translational and rotational temperatures, about 10 degrees above the absolute zero. The work will provide information on the structures and internal motions (dynamics) of the complexes, as well as on their electronic properties such as the electric dipole moment. The results will provide fundamental information about the nature of weak interaction forces between molecules and on intermolecular potential functions, and will contribute to the data base needed to develop and test models and theories which can guide chemists and biochemists in how compounds can interact and grow into larger clusters. %%% The clusters which will be studied constitute a state of matter that is intermediate between that of the dilute gas and the condensed phase and play a crucial role in condensation and evaporation phenomena. Weak intermolecular forces also play a decisive role in the structure and function of biological systems, in which parts of a biological molecule interact with other parts to give it a structure characteristic of its function. Fundamental investigations on intermolecular forces as conducted in this research will also contribute to the data base on which the theories for the prediction of new biochemical substances can be tested and calibrated.