摘要
在M06/6-311++G(d,p)和MN15/6-311++G(2df,pd)双水平,研究了α-丙氨酸(α-Ala)与Cr^(3+)的配合物S-α-Ala·Cr^(3+)的手性反转,结合极化连续介质的SMD模型方法研究了水溶剂的作用。S-α-Ala·Cr^(3+)的手性反转有3个通道:a通道是氨基N作质子转移媒介;b通道是羰基O和氨基N联合作质子转移媒介;c通道是羰基O作质子转移媒介。势能面研究表明:气相S-α-Ala·Cr^(3+)在a、b、c通道手性反转的活化能分别是295.6、305.5、123.6 k J/mol;水液相S-α-Ala·Cr^(3+)在a通道的活化能降至95.8 k J/mol,在b通道和c通道的活化能降至108.0 k J/mol。结果表明:气相α-Ala·Cr^(3+)能缓慢消旋,因此光学纯的α-Ala·Cr^(3+)不能在气固相下长期保存;水液相下α-Ala·Cr^(3+)能缓慢消旋,α-Ala·Cr^(3+)只能短期且少量的用于生命体同补α-Ala和Cr^(3+)。
The chiral reversal mechanism of α-alanine (α-Ala) and trivalent chromium(Cr^(3+)) complexes is investigated at the M06/6-311++G(d,p) and MN15/6-311++G(2df,pd) double level.The effect of aqueous solvent is investigated by using the SMD model method of polarized continuum.The chiral reverse of S-α-Ala·Cr^(3+)has 3 channels,and the amino group N atom acts as the medium for proton transfer in channel a;the combination of carbonyl group O atom and amino group N atom acts as the medium for proton transfer in channel b;the carbonyl group O atom acts as a medium for proton transfer in channel c.The research on potential energy surface shows:under the gas phase,the chiral reverse activation energies of S-α-Ala·Cr^(3+)in channel a,b and c are 295.6,305.5 and 123.6 k J/mol,respectively;Under the aqueous liquid phase the activation energy of S-α-Ala·Cr^(3+)decreases to 95.8 k J/mol in channel a and it decreases to 108.0 k J/mol in channel b and c.The results show that α-Ala·Cr^(3+)can be racemized slowly in the gas phase,and the optically pureα-Ala·Cr^(3+)cannot be preserved for a long time in the gas-solid phase;The racemization rate of α-Ala·Cr^(3+)is not very slow in aqueous liquid phase,and α-Ala·Cr^(3+)can be racemated slowly and minimally for supplementing α-Ala and Cr^(3+)to living organisms.
作者
马宏源
乔朝阳
张雪娇
刘芳
于秀斌
佟华
王佐成
MA Hongyuan;QIAO Chaoyang;ZHANG Xuejiao;LIU Fang;YU Xiubin;TONG Hua;WANG Zuocheng(College of Physics,Baicheng Normal University,Baicheng 137000,Jilin,China;Network Center,Baicheng Normal University,Baicheng 137000,Jilin,China)
出处
《武汉大学学报（理学版）》
CAS
CSCD
北大核心
2023年第3期363-372,共10页
Journal of Wuhan University:Natural Science Edition
基金
吉林省教育厅科学研究规划项目(JJKH20210010KJ)
吉林省自然科学基金(20130101131JC)。
关键词
Α-丙氨酸
三价铬
密度泛函理论
手性反转
水溶剂效应
能垒
α-alanine
trivalent chromium
density functional theory
chiral reverse
water solvent effect
energy barrier
