【作者】 吴怀选；

【导师】 胡义华；

【作者基本信息】 广东工业大学 ， 材料物理与化学， 2004， 硕士

【摘要】 稀有气体原子、小分子与芳香大分子组成的范德华复合物的相关研究受到广泛的关注。范德瓦尔斯（vdW）复合物是原子或分子间通过多极矩和色散相互作用形成的弱键能复合物，它们的键能比较弱，一般为100～1000cm^-1。在过去的二十年中，人们对弱成键复合物的研究兴趣非常浓厚，因为它们能够提供分子内部的细节信息，比如多极矩、分子的相互作用势等等，而这些信息对我们理解宏观物质的物理和化学性质至关重要。并且，范德华复合物是研究分子间能量转移、振动驰豫和振动预解离等过程的理想物质。 本文采用理论和实验的方法对vdW复合物C₆H₅CH₃…N₂、Ar进行了研究，并用三维线性谐振子波函数和纳能-琼斯势函数的量子计算方法得出vdW复合物的振动能级，计算值和实验光谱相符合。实验中采用了高分辨率的共振电离光谱技术和超声分子束技术，通过共振电离光谱和飞行时间质谱技术的手段探明了复合物C₆H₅CH₃…N₂、Ar的电子态、振动态以及甲基（CH₃）内转动的详细情况。由理论计算和同位素效应对光谱的分析作了合理的归属，获得了复合物C₆H₅CH₃…N₂、Ar的分子间相对振动模式和内转动的能级跃迁完整信息。 对比同位素分子C₆D₅CD₃…N₂的光谱，我们合理地归属了C₆H₅CH₃…N₂的光谱，实验得出C₆H₅CH₃…N₂的激发态和基态的键能分别是494cm^-1和474cm^-1，与理论计算一致。文中还阐述了复合物C₆H₅CH₃…Ar和C₆D₅CD₃…Ar的共振电离光谱的理论和实验研究，得出甲基的内转动能级、氩原子在复合物C₆H₅CH₃…Ar和C₆D₅CD₃…Ar中的外部振动能级和三种振动模式。更多还原

【Abstract】 Many experiments of van der Waals complexes which consist of relatively large aromatic molecules bound to rare-gas atoms or small molecules have been studied. Van der Waals(vdW) complexes are weak bonding complexes formed by atoms or molecules through interaction of electric multipole moments and dispersion forces. These complexes are characterized by their comparatively low binding energy (100-1000cm-1). During the last two decades , great interest has been aroused in the study of weak bonding complexes, as it can provide detail information on intermolecular properties such as multipole moments .interaction potentials, etc., which are highly important for us to understand the macroscopic physical and chemical properties of matter .Moreover ,the complexes of this kind are ideal objects for studying the processes of intermolecular energy transference, vibrational relaxation and predissociation which are the bases for studying macroscopic phenomena .In this paper ,we study the vdW (C6H5CH3...N2 Ar) vibrations in complexes by using a combined experiment and theoretical studies of resonant ionization spectra. For complexes, vdW vibration levels are calculated by the quantum method of linear -combination of three-dimensional harmonic oscillator products and Lennard-Jones potential, which is very close to the experimental spectrum . In our experiments, these complexes, produced in supersonic beam expansions, are amenable to high resolution resonant two-photons ionization spectroscopy, which make it possible to obtain detailed information on their electronic -vibrational states. Through resonant ionization spectra and together with time-of-flight mass spectrometry in supersonic molecular beam, the internal rotation for CH3 and intermolecular vibration for atom Ar (or N2) in the complexes (C6H5CH3... Ar N2) are exhibited . we obtain the complete information and a whole microscopic picture of the intermolecular actions and relative motions of these complexes .All observed bands are rationally assigned by isotope effect and calculated at the internal rotational levels and external vibrational levels are obtained.By comparing the spectra of isotopic complex C6D5CD3...N2, we have tentatively assigned all the observed spectral features to the complex C6H5CH3...N2.The binding energies for the complexes C6H5CH3...N2 in the excited electronic state and in the ground electronic state are about 494cm-1 and 474cm-1,which are very close to the calculated values. A experimental and theoretical studies of resonant ionization spectra for van der Waals complexes C6H5CH3...Ar and C6D5CD3...Ar are also reported. The internal rotation for CH3 and intermolecular vibration for atom Ar in the complexes are exhibited.The internal rotational levels .external vibrational levels and three modes frequencies of van der Waals vibrations for complexes C6H5CH3...Ar are obtained.更多还原