Mg(NH_2)_2与LiH放氢反应机理的密度泛函理论研究  

Theoretical Study on Reaction Between Mg(NH_2)_2 and LiH

作　　者：陈玉红[1,2] 董肖[1,2] 吕晓霞[1] 张梅玲[1] 张材荣[1] 康龙[2] 罗永春[2] 

机构地区：[1]兰州理工大学理学院,兰州730050 [2]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,兰州730050

出　　处：《计算物理》2012年第6期906-912,共7页Chinese Journal of Computational Physics

基　　金：国家自然科学基金(10547007);甘肃省自然科学基金(1010RJZA042);兰州理工大学博士基金(BS10200901)资助项目

摘　　要：采用密度泛函理论B3LYP方法研究Mg(NH2)2与LiH放氢反应机理,在6-311G(d,p)基组水平上对反应物、中间体、过渡态及产物进行全几何参数优化,频率分析和内禀反应坐标(IRC)计算证实中间体和过渡态的正确性和相互连接关系.计算结果表明,反应分三个阶段,包括第一步氢取代反应,第二步氢取代反应和脱氢后的异构化反应.反应有两条途径,其中第二步对位氢取代反应所对应通道为主反应通道.反应释放的H2中两个氢原子分别来源于Mg(NH2)2和LiH.Reaction mechanism between Mg（NH2）2 and LiH are investigated with a B3LYP method of density functional theory.Geometries and harmonic vibration frequencies of reactants,intermediates,transition states and products are calculated at B3LYP/6-311G（d,p） level.Vibration analysis and intrinsic reaction coordinates（IRC） calculation at the same level are applied to validate connection of stationary points.It indicates that the reaction has three stages.They are the first step of hydrogen substitution,the second step of hydrogen substitution and isomerization after removal of hydrogen.There are two pathways,in which a channel of the second step of alignment hydrogen substitution reaction is the main channel.The two hydrogen atoms in H2 released are from Mg（NH2）2 and LiH.

关 键 词：密度泛函理论 Mg(NH2)2 LIH 过渡态 

分 类 号：O641.121[理学—物理化学] O643.12[理学—化学]