关键词: 自洽反应场, 谷氨酸； 手性转变； 密度泛函理论； 过渡态； 微扰理论； 

Abstract: We studied the chiral transition and water solvation effect of two kinds of the most stable configurations of glutamic acid molecules by using the B3LYP method of density functional theory, the MP2 method of perturbation theory, and SMD model method of selfconsistent reaction field (SCRF) theory. The results show that the dominant channels of the configuration one are channel a and channel b, stepdetermining free energy barriers are 242.3, 245.7 kJ/mol, respectively. The dominant channel of the configuration two is the  channel a, and stepdetermining free energy barrier is 243.5 kJ/mol which is generated by the transition state of proton transfer from the chiral carbon to the amino N. The water solvation effect enables the stepdetermining energy barrier is reduced to 101.5 kJ/mol for the dominant channel of the configuration one. The stepdetermining reaction rate is 1.002×10^-5s^-1 at  298.15 K, and it is 3.802×10^-5 s^-1 at 310.00 K. So the  glutamic acid molecules can slowly realize optical isomerism in the life rich water environment.

Key words: density functional theory, glutamic acid, selfconsistent reaction field, chiral transition, perturbation theory, transition state