扶手椅型单壁氮化硼纳米管的尺寸对缬氨酸旋光异构的限域影响  

Confinement effect the size of armchair single-walled boron nitride nanotubes on optical isomers of valine molecules

作　　者：姜春旭 杨晓翠[1,3] 绳绍旭 白杰 丛建民[4] 王佐成[1,3] JIANG Chunxu;YANG Xiaocui;SHENG Shaoxv;BAI Jie;CONG Jianmin;WANG Zuocheng(Theoretical Computing Center, Baicheng Normal University, Baicheng 137000, China;Communication College, Baicheng Normal University, Baicheng 137000, China;College of Physics, Baicheng Normal University, Baicheng 137000, China;College of Life Science,Baicheng Normal University, Baicheng 137000, 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]白城师范学院物理学院,吉林白城137000 [4]白城师范学院生命科学学院,吉林白城137000

出　　处：《中山大学学报（自然科学版）》2019年第1期110-119,共10页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：吉林省科技发展计划基金(20130101308JC);吉林省高校大学生创新项目(2017第A36号)

摘　　要：采用QM与MM组合的ONIOM方法,对标题反应进行了研究。结构分析表明:SWBNNT (硼氮纳米管)(5,5)的限制致缬氨酸分子骨架明显形变,同时SWBNNT (5,5)也发生了形变。计算表明:以氨基氮为质子转移桥梁的旋光异构是优势反应通道。缬氨酸限域在SWBNNT (5,5)时,旋光异构决速步的内禀能垒是318.41 kJ·mol^(-1);缬氨酸限域在SWBNNT (6,6)时,质子迁移与羟基旋转同步与分步进行的旋光异构决速步的内禀能垒分别是306.42和306.93 kJ·mol^(-1)。均比裸反应优势通道的决速步能垒268.93 kJ·mol^(-1)显著升高。缬氨酸限制在SWBNNT (7,7)时,旋光异构决速步的内禀能垒是262.81 kJ·mol^(-1),与裸反应相差无几。结果表明:SWBNNT (5,5)和SWBNNT (6,6)的限域对缬氨酸旋光异构具有明显的负催化作用。The title reaction was performed by ONIOM method combined with QM and MM. Structural analysis showed that the skeleton of valine deformationed obviously induced by confinement effect of SWBNNT (5,5), at the same time SWBNNT (5,5) also had an obvious deformation. Calculation showed that the optical isomeric reaction channel with amino nitrogen as the proton transfer bridge had advantages for valine molecules. When valine molecules confined in SWBNNT (5,5), the intrinsic energy barrier of optical isomers rate-limiting step was 318.41 kJ·mol^-1 . When proton transfer and hydroxyl rotation occurred simultaneously and stepwise, the related intrinsic energy barrier of optical isomers rate-limiting step were 306.42 and 306.93 kJ·mol^-1 in SWBNNT(6,6), respectively, which were significantly higher than the intrinsic energy barrier of the bare reaction dominant channel with the value of 262.81 kJ·mol^-1 . When valine molecules confined in SWBNNT(7,7), the intrinsic energy barrier of optical isomers rate-limiting step was 262.81 kJ·mol^-1 , which was no different from that in the naked reaction. The results showed the confinement of SWCNT (5,5) and SWCNT(6,6) had an obvious negative catalysis to optical isomers of valine molecules.

关 键 词：缬氨酸 旋光异构 单壁氮化硼纳米管 ONIOM方法 密度泛函理论 过渡态 微扰论 

分 类 号：O641.12[理学—物理化学]