(H2O)n(n=0～2)催化HS和HOCl反应机理的理论研究  

(H_2O)_n(n=0～2) catalyzed reaction mechanism of HS and HOCl:a theoretical investigation

作　　者：王智香 李琦 曹佳[1] 樊博 王耀 WANG Zhi-xiang;LI Qi;CAO Jia;FAN Bo;WANG Yao(College of Chemistry ＆ Chemical Engineering, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan＇an University, Yan＇an 716000, China)

机构地区：[1]延安大学化学与化工学院,陕西省化学反应工程重点实验室,陕西延安716000

出　　处：《分子科学学报》2017年第6期441-446,共6页Journal of Molecular Science

基　　金：国家自然科学基金资助项目(21543017);国家级大学生创新创业训练计划项目(201510719288);2015年陕西省大学生创新创业训练计划项目(1449);延安大学青年项目(YDQ2014-32);延安大学化工学院青年基金资助项目(YDHG2014-12)

摘　　要：在CCSD(T)/6-311+G(3df,2p)//M06-2X/6-311+G(3df,2p)水平上研究了(H_2O)n(n=0~2)催化HS和HOCl的反应机理.结果表明,HS与HOCl反应中HS夺取HOCl上的H原子形成产物H_2S和ClO.在无水催化时,该反应存在2种不同的路径(分别经过过渡态TS1和TS2,二者互为顺反结构),对应的能垒分别为100.28和100.91kJ/mol,到达产物(H_2S+ClO)需吸收18.99kJ/mol能量,反应不易发生;在单个水分子参与时,水分子可通过形成弱相互作用或者作为H原子转移桥梁影响反应机理,获得了4种水催化路径,能垒(间于53.97~92.39kJ/mol之间)均低于无水催化过程.同时发现,在反应到达产物前,水分子可以与产物形成中间体IM,IM相对能仅为0.46kJ/mol,有利于产物形成;有2个水分子参与反应时,找到了3条催化路径,最优反应路径过渡态TS7的能垒为45.05kJ/mol,低于无水催化过程,相比单个水分子最优路径能垒(53.97kJ/mol)并无显著降低.Water molecule catalyzed reaction mechanism of HS and HOCl is studied at the CCSD（T）//M06-2 X/6-311＋G（3df,2p）level of theory.The results suggest the main products are H_2S and ClO for the reaction of HS and HOCl.In the gas phase,the title reaction including two pathways proceeds via transition state TS1 and TS2,respectively.The barrier heights of TS1 and TS2 are 100.28 and 100.91 kJ/mol,respectively,which is not easy to occur.When single water molecule is involved,water molecule interacts with reactants by weak interaction or as a hydrogen atom transfer bridge to affect the reaction mechanism.Four kinds of water catalyzed mechanism are found.The barrier heights of water molecule catalyzed processes（53.97~92.39 kJ/mol）are lower than that of anhydrous catalysis process.Additionaly we found that when the arrival of the reaction products,water molecules can form intermediate IM with the relative energy of 0.46 kJ/mol,which is advantageous to the product form.Three pathways are found in presence of two water molecules.The barrier height of the main reaction path transition state TS7 is 45.05 kJ/mol.

关 键 词：HOCL HS 单个水分子催化 反应机理 

分 类 号：O641[理学—物理化学]