气相α-丙氨酸钴(Ⅱ)的旋光异构机理和水分子(簇)的作用及水溶剂效应  

The Optical Isomerism Mechanism of Gas Phaseα-AlanineCo(Ⅱ)and the Role of Water Molecules(Clusters)and Water Solvent Effect

作　　者：毛杰伟 佟华[1,2] 徐亚华 刘芳[1] 杨清荟 雷泽平 张雪娇[2] 王佐成[1,2] MAO Jiewei;TONG Hua;XU Yahua;LIU Fang;YANG Qinghui;LEI Zeping;ZHANG Xuejiao;WANG Zuocheng(College of Physics, Baicheng Normal University, Baicheng, Jilin 137000, China;Theoretical Computing Center, Baicheng Normal University, Baicheng, Jilin 137000, China;Department of Cardiology, Baicheng Central Hospital, Baicheng, Jilin 137000, China)

机构地区：[1]白城师范学院物理学院,吉林白城137000 [2]白城师范学院理论计算中心,吉林白城137000 [3]白城市中心医院心血管内科,吉林白城137000

出　　处：《复旦学报（自然科学版）》2022年第1期93-103,共11页Journal of Fudan University：Natural Science

基　　金：吉林省教育厅科学研究规划项目(JJKH20210010KJ);全国大学生创新项目(202110206019);吉林省自然科学基金项目(20130101308JC)。

摘　　要：采用密度泛函理论的M06和MN15方法,结合自洽反应场理论的SMD模型,研究了气相下两性及中性α-丙氨酸(α-Ala_1和α-Ala_2)与Co2+配合物稳定构型的旋光异构、水分子(簇)的作用及水溶剂效应。研究发现:α-Ala_1·Co2+的旋光异构有a和b两个通道,a是质子以羰基氧为桥迁移;b是α-氢迁移到羰基氧后,质子化氨基的质子在纸面内侧向α-碳迁移。α-Ala_2·Co2+的旋光异构也有两个通道a和b,a是螯合环打开向α-Ala_1·Co2+异构后,接α-Ala_1·Co2+的旋光异构;b是羧基内质子迁移后,α-氢向羰基氧迁移。势能面计算表明:α-Ala_1·Co2+在a和b通道旋光异构反应的活化能都是271.7 kJ·mol-1;α-Ala_2·Co2+的旋光异构是在a通道异构到α-Ala_1·Co2+后,再接α-Ala_1·Co2+的异构具有优势,反应活化能是250.9 kJ·mol-1。水分子(簇)的作用使α-Ala_1·Co2+和α-Ala_2·Co2+在优势通道的反应活化能分别降到150.1和129.3 kJ·mol-1;水溶剂效应使S-A·Co_1和S-A·Co_2旋光异构反应的活化能变为119.5 kJ·mol-1。The optical isomerism of the stable configuration of the amphoteric neutralα-alanine(α-Ala_1andα-Ala_2)and Co2+complexes,the role of water molecules(clusters)and water solvent effect in the gas phase has been studied using the M06 and MN15 methods based on density functional theory combined with the Slovation Model Density(SMD)model based on self-consistent reaction field theory.The study found that the optical isomerism ofα-Ala_1·Co2+has two channels a and b.In channel a,the proton transfers with carbonyl oxygen as a bridge.In channel b,the protonated amino proton transfers toα-C inside the paper afterα-H is transferred to carbonyl oxygen.The optical isomerism ofα-Ala_2·Co2+also has two channels a and b.In channel a,the chelating ring is opened to isomerism toα-Ala_1·Co2+following the optical isomerism ofα-Ala_1·Co2+.In channel b,α-H transfers to carbonyl oxygen after the carboxyl inner proton is transferred.The potential energy surface shows that the activation energy of optical isomerism reactions ofα-Ala_1·Co2+in channel a and b are both 271.7 kJ·mol-1.α-Ala_2·Co2+isomerism toα-Ala_1·Co2+following the optical isomerism ofα-Ala_1·Co2+in channel a has the most advantage,the activation energy of the reaction is 250.9 kJ·mol-1.The effect of water molecules(clusters)reduce the activation energy ofα-Ala_1·Co2+andα-Ala_2·Co2+in the dominant channels to 150.1 kJ·mol-1 and 129.3 kJ·mol-1 respectively.Water solvent effect makes the activation energy of S-A·Co_1 and S-A·Co_2 optical isomerism reaction into 119.5 kJ·mol-1.

关 键 词：Α-丙氨酸 二价钴离子 旋光异构 密度泛函 过渡态 溶剂效应 

分 类 号：O641.12[理学—物理化学]