外电场下氯甲烷的光谱和解离特性  

Spectra and Dissociation Characteristics of Methyl Chloride Under External Electric Field

作　　者：王啸卿 刘玉柱[1,2] 李相鸿[3] 王俊锋[1,2] 林华[1,2] 秦朝朝[4] 

机构地区：[1]南京信息工程大学物理与光电工程学院,江苏南京210044 [2]江苏省大气环境与装备技术协同创新中心,江苏南京210044 [3]皖南医学院弋矶山医院临床药学部,安徽芜湖241001 [4]河南师范大学物理系,河南新乡453007

出　　处：《大气与环境光学学报》2017年第3期195-201,共7页Journal of Atmospheric and Environmental Optics

基　　金：国家自然科学基金;11304157;U1404112;11504175;江苏省六大人才高峰高层次人才项目;2015-JNHB-011;南京信息工程大学大学生实践创新训练计划项目;201610300042~~

摘　　要：为了研究外电场对氯甲烷分子光谱和解离特性的影响,采用密度泛函理论(density functional theory,DFT)B3LYP方法在6-311++G(d,p)基组水平上研究了不同外电场(-0.03~0.03 a.u.)对氯甲烷分子结构以及解离特性的影响,包括键长、分子能隙、红外光谱以及解离势能面等.计算结果表明,随着Z方向(C-Cl连线方向)外电场从-0.03 a.u.逐渐增加到0.03 au.,C-Cl键的键长逐渐增大而C-H键的键长几乎不变,分子能隙E_G先增大后减小,当外加电场等于0.01 a.u.时达到峰值。C-C1伸缩(stretching,STR)振动的频率是逐渐减小的,而红外光谱(infrared,IR)振动强度是逐渐增加的.通过进一步计算研究发现,随着外电场(0~0.03 a.u.)继续增强,CH_3Cl分子的势能曲线逐渐降低,解离能逐渐减小.当外电场大约是0.04 a.u.时解离能最小,发生解离。因此,可以通过改变外电场来控制CH_3Cl分子的降解。In order to analyze the influence of external electric field on the molecular spectra and dissociation of methyl chloride, density functional （DFT） theory at B3LYP/6-311G＋＋（d,p） level is used to investigate the influence on the molecular structure of the chloromethane molecule and dissociation properties under different external electric field （-0.03～0.03 a.u.）, including molecular bond length, energy gap, IR spectra, dissociation curve and so on. The calculation results show that with external electric field increase from -0.03 a.u. to 0.03 a.u. step by step, on the Z direction（C-Cl line）, C-Cl bond length increases and C-H bond length is almost the same. When the external electric field is equal to 0.01 a.u., the peak value is reached. The molecular energy gap increases and then decreases. The C-Cl stretching （STR） vibration frequency gradually decreases, while infrared （IR） vibration intensity gradually increases. Further research and analysis indicate that with the continuous increase of the external electric field （0～0.03 a.u.）, the energy curve of CH3Cl molecule decreases gradually and the dissociation decreases too. When the external electric field is about 0.04 a.u., the dissociation energy is at the minimum, and the dissociation occurs. Therefore, it can control the degradation of the CH3Cl molecule by changing the external electric field.

关 键 词：氯甲烷 外电场 解离 红外光谱 分子能隙 

分 类 号：O561[理学—原子与分子物理]