三价羰基硫离子(OCS^(3+))二体解离过程模拟研究  

Simulation study of two-body dissociation mechanism of trivalent carbonyl sulfide ion(OCS^(3+))

作　　者：申丽丽 李晓勤[1] 张景川[1] 柴学平[1] 金国强 SHEN Li-Li;LI Xiao-Qin;ZHANG Jing-Chuan;CHAI Xue-Ping;JIN Guo-Qiang(College of Mechanical and Electrical Engineering,Tarim University,Alar 843300,China)

机构地区：[1]塔里木大学机械电气化工程学院,阿拉尔843300

出　　处：《原子与分子物理学报》2023年第6期55-59,共5页Journal of Atomic and Molecular Physics

基　　金：中国科学院青年创新促进会项目(2018448)。

摘　　要：基于Gaussian量子化学模拟软件采用不同基组(6-31G**和TZVP)下的B3LYP方法对基态三价羰基硫离子(OCS^(3+))的势能曲线进行分析,得到了三价羰基硫离子可能的解离通道.当固定C—O键长为OCS分子的构型键长时(2.1a.u.),通过模拟基态OCS^(3+)离子沿着C—S键断裂的势能曲线,发现沿着C—S键的势能曲线是一个具有小势垒的排斥态;相反,当固定C—S键长为OCS分子的构型键长时(2.9a.u.),基态OCS^(3+)离子沿着C—O键的势能曲线是一个势垒较大的排斥态,根据弗兰克-康登原理可知,基态OCS^(3+)离子倾向于以断裂C—S键的方式进行解离.通过搜索基态OCS^(3+)离子过渡态、IRC路径分析进一步确定了基态OCS^(3+)离子具体的解离通道:OCS^(3+)→CO^(+)+S^(2+).最后通过对反应物和产物的Mulliken电荷分布和键长的分析,得到与前面一致的结论.By using the B3LYP methods in Gaussian package and the 6-31G^(**) and TZVP basis sets,the potential energy curves(PECs)of OCS^(3+) ion in the ground electronic state is deduced,and its dissociation mechanism is explored.If fixing the C—O bond length at the equilibrium internuclear distance of OCS,which is 2.1 a.u.,we found the PEC along C—S is repulsive with a very low barrier.Conversely,if the C—S is fixed at 2.9 a.u.,the PEC along C—O presents a very deep minimum and a high and broad barrier.According to the Frank Condon Principle,above phenomenon suggests that the ground state OCS^(3+) will dissociate through the breakup of C—S bond:OCS^(3+)→CO^(+)+S^(2+).The following calculation of the transition state and IRC further confirms this fragmentation pathway.Finally,the Mulliken charge distribution and molecular bond length of reactants and products are analyzed,the result is also consistent with our conclusion.

关 键 词：羰基硫 解离机制 密度泛函 过渡态 

分 类 号：O561.4[理学—原子与分子物理]