利用同步辐射光电离质谱技术研究甲苯分子离解光电离动力学

发布时间：2018-04-10 03:26

本文选题：同步辐射　切入点：真空紫外光电离　出处：《东华理工大学》2017年硕士论文

【摘要】：甲苯的光电离离解动力学研究是物理学、化学、以及大气环境科学的重要基础研究课题。本论文主要是利用同步辐射真空紫外光单光子电离、超声分子束和反射式飞行时间质谱技术相结合,开展对甲苯分子光电离解离动力学的实验研究。通过本研究确定甲苯母体分子的电离能,离解产物的出现势和离解能以及分子离子离解动力学等方面的数据。与此同时,利用Gaussian03软件G3方法计算甲苯分子光电离和光离解过程,并结合实验数据讨论甲苯分子光电离和离解机理。主要成果如下:在实验层面,研究了甲苯在7.5~25.5 eV的光电离离解过程。由实验得到甲苯的单电离和双电离的电离能分别为8.82和23.09 eV。同时也测得了通过电离解离产生的碎片离子C7H7+,C6H5+,C5H6+,C5H5+,C5H3+,C4H5+,C4H4+,C4H3+,C4H2+,C3H3+,C2H3+的光电离效率谱,大部分碎片离子的出现势和文献值都是符合的很好。利用量化计算对甲苯光电离解离进行理论计算,得到其电离能理论值为8.90 eV,与实验值基本吻合。理论计算也得到C7H7+,C5H6+,C5H5+碎片离子的出现势分别为11.15或11.03,13.69,16.28 eV。然后将实验和理论计算结果结合,详细的讨论了C7H7+,C5H6+,C5H5+离子的解离过程,同时理论计算也获得了解离过程中所涉及的中间体和过渡态。本研究将为原子分子数据库,提供甲苯分子的光电离离解动力学方面的参考信息;同时也为大气层甲苯污染的防治提供依据。
[Abstract]:The study of photodissociation kinetics of toluene is an important basic research topic in physics, chemistry and atmospheric environmental science.In this thesis, the photoionization kinetics of toluene was studied by using synchrotron radiation vacuum ultraviolet single photon ionization, ultrasonic molecular beam and reflective time of flight mass spectrometry.Through this study, the ionization energy of toluene parent molecule, the appearance potential and dissociation energy of dissociation products and the dissociation kinetics of molecular ions were determined.At the same time, the photoionization and photodissociation processes of toluene were calculated by Gaussian03 software G3, and the mechanism of photoionization and dissociation of toluene was discussed with experimental data.The main results are as follows: at the experimental level, the photodissociation process of toluene at 7.5U 25.5 EV was studied.The ionization energies of single ionization and double ionization of toluene were 8.82 and 23.09 EV, respectively.At the same time, the photoionization efficiency spectra of the fragment ion C7H7 C6H5, C5H6, C5H5, C5H5, C4H5, C4H4, C4H3, C4H2, C3H3 and C2H3 produced by ionization were also measured.The theoretical value of ionization energy of toluene is 8.90 EV, which is in good agreement with the experimental value.Theoretical calculations also show that the potential of C7H7 C5H6 C5H5 fragment ions is 11.15 or 11.03 ~ 13.691 ~ 16.28 EV, respectively.Then the dissociation process of C7H7 C5H6 C5H5 ions is discussed in detail by combining the experimental and theoretical results. The intermediate and transition states involved in the dissociation process are also obtained by theoretical calculation.This study will provide reference information on photodissociation kinetics of toluene in atomic and molecular databases, as well as the prevention and control of toluene pollution in the atmosphere.
【学位授予单位】：东华理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.1;O657.63

【参考文献】