在b3lyP/6-31g(d,P)水平上研究了2-(2-巯苯基)苯并噁唑气态中五种异构体(E1,E2,E3,E4和k)在气态中的稳定性及其在基态下的质子转移,同时结合极化连续介质模型(PCM)研究了水、二甲亚砜、乙腈、乙醇、苯胺和环己烷等对2-(2-巯苯基)苯并噁唑溶剂化作用的影响.研究结果表明,醇式异构体E1为2-(2-巯苯基)苯并噁唑的优势构型;在E1向k(酮式异构体)转变过程中,存在一个较小的能垒;当考虑零点振动能(zPVE)后,逆向能垒消失.在溶液中,随着溶剂极性的增强,醇式异构体E1与k之间的反应平衡向k方向移动,在非极性溶剂环己烷中,E1为优势构型,而在强极性水溶液中,k为优势构型。The tautomers(E1,E2,E3,E4,and K) and the ground state intramolecular proton transfer reaction of 2-(2-mercaptophenyl)benzoxazole were studied at the B3LYP/6-31G(d,p) level.The effect of solvent(water,dimethylsulfoxide,acetonitrile,ethanol,aniline,and cyclohexane) was studied at the B3LYP/6-31G(d,p) level,using the polarizable continuum model.The results of density functional calculations indicate that the enol form E1 is the most stable tautomer at the ground state.In these solvents there is an equilibrium for 2-(2-mercaptophenyl)benzoxazole in the ground state between E1 and K,and the equilibrium shifts toward the tautomer K as the polarity of the solvent increases.E1 is the preferential conformation in cyclohexane,but K is the more stable tautomer in water.国家自然科学基金(Nos.20772027;20803020);973子课题(No.2003CB716005);中国博士后科学基金(No.20070410805)资助项
