气相环境下丙氨酸Mn(Ⅱ)配合物的手性转变机理  

Chiral Transition Mechanism of Mn(Ⅱ)and Alanine Complexes in Gas Phase Environment

作　　者：张雪娇 李冰[1,3] 姜春旭[1,2] 马宏源 杨晓翠[1,4] 王佐成[1,4] ZHANG Xuejiao;LI Bing;JIANG Chunxu;MA Hongyuan;YANG Xiaocui;WANG Zuocheng(Theoretical Computing Center.Baicheng Normal University,Baicheng 137000.Jilin.China;Communication C olege,Baicheng Normal University,Baicheng 137000,Jilin,China;College of Mechanical Engineering.Baicheng Normal University,Baicheng 137000,Jilin,China;College of Physics.Baicheng Normal University,Baicheng 137000,Jilin,China)

机构地区：[1]白城师范学院理论计算中心,吉林白城137000 [2]白城师范学院传媒学院,吉林白城137000 [3]白城师范学院机械工程学院,吉林白城137000 [4]白城师范学院物理学院,吉林白城137000

出　　处：《武汉大学学报（理学版）》2020年第4期345-353,共9页Journal of Wuhan University:Natural Science Edition

基　　金：吉林省教育厅科学研究“十三五”规划项目(JJKH20200002KJ);吉林省科技发展计划自然科学基金(20130101308JC,20160101308JC)。

摘　　要：采用密度泛函理论的M06和MN15方法,研究了气相环境下两个稳定的丙氨酸异构体(S-Ala1和S-Ala2)与Mn^2+配合物(S-A1和S-A2)的手性转变。研究发现:S-A1的手性转变有3个通道a、b和c,a通道先是α-氢向羰基O迁移;b通道是羧基Mn^2+螯合环的打开与质子从质子化氨基向羧基负离子的O迁移协同进行;c通道是α-氢先向氨基N迁移。S-A2的手性转变有2个通道a和b,a通道是α-氢先向氨基N迁移;b通道是先进行羧基内的H迁移。势能面计算表明:S-A1手性转变反应的b通道具有优势,活化自由能垒约为247. 0 kJ/mol^-1;S-A2手性转变反应的a通道具有优势,活化自由能垒约为329. 0 kJ·mol^-1。结果表明,Ala与Mn^2+的配合物可以很好地保持其手性特征。The chiral transition of the complexes(S-A1 and S-A2) of two stable alanine isomers(S-Ala1 and S-Ala2)and Mn2+has been studied using the M06 method and MN15 method based on density functional theory. The study shows that the S-A1 chiral transition has three pathways a, b and c. In pathway a, α-H is transferred firstly to carbonyl O atom. In pathway b, the opening of the carboxyl-Mn^2+chelate ring is coordinated with the proton migration from protonated amino to carboxy anion O. In pathway c, α-H is transferred firstly to amino N atom. The S-A2 chiral transition has two pathways a and b. In pathway a, α-H is transferred firstly to amino N atom. In pathway b, H migration within the carboxyl group occurs first. The potential energy surface calculation shows that the dominant pathway of the chiral transition of S-A1 is pathway b, and the activation free energy barrier is approximately 247.0 kJ·mol^-1;the dominant pathway of the chiral transition of S-A2 is pathway a, and the activation free energy barrier is approximately 329.0 kJ·mol^-1. The results indicate that the complex of Ala and Mn2+can maintain its chiral characteristics well.

关 键 词：丙氨酸 二价锰离子 手性转变 密度泛函理论 过渡态 能垒 

分 类 号：O641.12[理学—物理化学]