Analysis of the Intermolecular Dynamics of Open-shell Radical Complexes

开壳层自由基配合物的分子间动力学分析

基本信息

批准号：
07454148
负责人：
ENDO Yasuki
金额：
$ 4.8万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

Compared to the closed shell molecular complexes, molecular complexes containing open shell species species or ionic have little been studied by high-resolution spectroscopic methods. The present project intended to investigate these species by using Fourier-transform microwave spectroscopy or mm-wave/cm-wave double resonance spectroscopy in order to elucidate intermolecular interactions. Specific interest lies in the roles of the unpaired electron in the open shell species and the charge in the ionic species how they contribute to the intermolecular dynamics.During the period of present research project, we observed rotational spectra of Ne-OH,Kr-OH,Ar-SH,H_2O-OH,H_2O-SH,Ar-HCO^+, and Kr-HCO^+ for the first time. Results of Ne-OH and Kr-OH and Kr-OH were analyzed by a method previously applied to the Ar-OH system, considering large amplitude motion of the OH moiety and the couplings of the spin and orbital angular momenta of the unpaired electron. The intermolecular interaction potent … More ials were compared with that of Ar-OH,and their differences were explained by considering the polarizabilities of the rage-gas atoms. Similar analysis has been applied to the analysis of Ar-SH.The resulting intermolecular potential for Ar-SH i quite different from those of Rg-OH systems : anisotropy around OH is much smaller than those of Rg-OH,undergoing large amplitude motion with larger amplitude.Spectroscopic detections of H_2O-OH and H_2S-SH are important as these complexes are closely related to the understanding of the hydrogen exchange reactions. The observed spectrum of H_2O-OH was analyzed as the system is a doublet asymmetric rotor with the orbital angular momentum in OH completely quenched. The two hydrogen atoms in H_2O showed appreciable magnetic hyperfine splittings suggesting some delocalization of the unpaired electron on the OH radical. Theintermolecular distance was explained as the two constituents were bonded by the hydrogen bonding with OH proton to be proton donor. The spectrum of H_2S-SH showed many anomaly and detailed analysis is still under way.The ionic complexes Ar-HCO^+ and Kr-HCO^+ were studied in detail including their various isotopomers, yielding precise determination of their molecular structure. The Rg-H distances thus obtained were much smaller than those of neutral complexes. They were well explained by considering a rather simple electrostatic model. The present results also agrees with large scale ab initio calculations including their intermolecular potentials indirectly estimated from the present experimental data.In order to understand intermolecular, we performed ad initio molecular orbital calculations for these systems. We obtained fair agreements for H_2O-OH and ion complexes. We expect that molecular orbital calculations will help further understanding of the intermolecular intermolecular for such systems. Less

与闭壳分子复合物相比，含有开壳物种或离子的分子复合物很少通过高分辨率光谱方法进行研究，本项目旨在通过使用傅里叶变换微波光谱或毫米波/厘米波谱来研究这些物种。波双共振光谱，以阐明分子间相互作用，特别感兴趣的是开壳物质中不成对电子的作用以及离子物质中的电荷如何对分子间相互作用做出贡献。在本研究项目期间，我们首次观测到Ne-OH、Kr-OH、Ar-SH、H_2O-OH、H_2O-SH、Ar-HCO^+和Kr-HCO^+的旋转光谱Ne-OH、Kr-OH 和 Kr-OH 的结果通过先前应用于 Ar-OH 系统的方法进行了分析，考虑了 OH 部分的大幅运动以及自旋和轨道角的耦合。将不成对电子的分子间相互作用势与Ar-OH进行了比较，并通过考虑愤怒气体原子的极化率来解释它们的差异。类似的分析已应用于Ar-SH的分析。 Ar-SH i 所产生的分子间势与 Rg-OH 体系的分子间势有很大不同：OH 周围的各向异性比 Rg-OH 的小得多，并且进行较大振幅的大幅运动。 H_2O-OH和H_2S-SH很重要，因为这些配合物与氢交换反应的理解密切相关，分析了H_2O-OH的观测光谱，因为该系统是双峰不对称转子，OH中的轨道角动量完全淬灭。 H_2O 中的两个氢原子表现出明显的磁性超精细分裂，这表明 OH 自由基上的不成对电子存在一定的离域现象。由于两种组分通过氢键与OH质子结合成为质子供体，H_2S-SH的光谱显示出许多异常，详细分析仍在进行中。离子配合物Ar-HCO^+和Kr-HCO^+。详细研究了它们的各种同位素异构体，从而精确测定了它们的分子结构，由此获得的 Rg-H 距离比中性配合物的距离小得多，通过考虑相当简单的静电，可以很好地解释它们。目前的结果也与大规模从头计算相一致，包括从目前的实验数据间接估计的分子间势。为了理解分子间，我们对这些系统进行了从头算分子轨道计算，我们对 H_2O-OH 进行了公平的计算。我们期望分子轨道计算将有助于进一步了解此类系统的分子间关系。