R型半胱氨酸体系电荷转移百分数的理论计算

采用密度泛函理论中的CAM-B3LYP方法, 在6-31G(d)基组水平上优化气相条件下R型半胱氨酸(R-Cys)分子的几何构型, 理论研究电子激发过程中R-Cys体系片段间的电荷转移特征, 并基于弛豫与非弛豫激发态密度计算片段间的电荷转移百分数. 结果表明: 对于SH片段, S0到S3的电荷转移百分数为57.96%； 对于COOH片段, S0到S1~S5各激发态的电荷转移百分数均为负值, 二者电荷转移的定性结果一致； 对于NH2片段, S0到S1和S4的电荷转移百分数分别为6.98%和31.45%.

Theoretical Calculation of Charge Transfer Percentagefor R Cysteine System#br#

Using the CAM B3LYP method of density functional theory, we optimized the geometric configuration of R-Cysteine (R-Cys) molecule in gas phaseat 6-31G (d) basis set, theoretically studied the charge transfer characteristics between fragments of R-Cys system during the electron excitation, and calculated the charge transfer percentage between fragments based on the excited state density of relaxation and non relaxation. The results show that for SH fragment, the charge transfer percentage from S0 to S3 is 57.96%. For COOH fragment, the charge transfer percentages of the excited states from S0 to S1—S5 are negative, and the qualitative results of charge transfer are consistent. ForNH₂ fragments, the charge transfer percentages from S0 to S1 and S4 are 698%and 3145%, respectively.