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

• 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
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07454148/
• 关键词: Open-shell molecule; Molecular complex; Fourier-transform microwave spectroscopy; Double resonance spectroscopy; Molecular ion complex; Intermolecular interaction; Molecular orbital method; 分子軌道法; 分子錯体; フリーラジカル; マイクロ波分光; 2重共鳴分光; 分子内大振幅運動

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

相对于闭壳层分子复合物，含开壳层物种或离子的分子复合物的高分辨光谱研究较少。本项目旨在通过使用傅里叶变换微波光谱或毫米波/厘米波双共振光谱来研究这些物种，以阐明分子间的相互作用。在本研究期间，我们首次观测到了Ne-OH，Kr-OH，Ar-SH，H_2 O-OH，H_2 O-SH，Ar-HCO^+，Kr-HCO^+的转动光谱。用Ar-OH体系的方法分析了Ne-OH、Kr-OH和Kr-OH的结果，考虑了OH基团的大振幅运动和未成对电子的自旋角动量与轨道角动量的耦合，计算了分子间相互作用势 ...更多信息 并与Ar-OH的结果进行了比较，从Ar-气体原子的极化率的角度解释了它们的差异。Ar-SH体系的分子间势与Rg-OH体系的分子间势有很大的不同：OH的各向异性比Rg-OH小得多，发生振幅较大的大振幅运动，H_2 O-OH和H_2S-SH的光谱检测是重要的，因为它们与氢交换反应的理解密切相关。对观测到的H_2 O-OH体系的光谱进行了分析，认为该体系是一个双重不对称转子体系，OH的轨道角动量完全猝灭。H_2O中的两个氢原子表现出明显的磁超精细分裂，表明OH自由基上的未成对电子发生了离域。分子间距离的产生是由于两组分之间以OH质子为质子供体通过氢键作用而形成的。H_2S-SH的光谱显示出许多异常，详细的分析仍在进行中，对Ar-HCO^+和Kr-HCO^+离子配合物进行了详细的研究，包括它们的各种同位素异构体，精确地确定了它们的分子结构。由此得到的Rg-H距离远小于中性配合物。通过考虑一个相当简单的静电模型，它们得到了很好的解释。本文的结果也与大规模从头计算结果相一致，包括由实验数据间接估算的分子间势能.为了理解分子间势能，我们对这些体系进行了从头计算.对H_2 O-OH和离子络合物的计算结果一致。我们期望分子轨道计算将有助于进一步理解这类体系的分子间相互作用。少

项目成果

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