溶质和溶剂极性对二氮杂苯异构体吸收光谱移动的影响

Effect of the Solute and Solvent's Polarity on the Absorption Spectra Shift of Diazine Tautomers

采用根据连续介质理论和热力学约束平衡态方法得到的新非平衡态静电溶剂化能公式,在单球孔穴点偶极模型近似下推导得到了吸收/发射光谱移动计算的新解析公式.在CASSCF(6,5)/6-31++G**水平上分别计算了邻位、间位、对位三种二氮杂苯异构体真空中的n→π*跃迁吸收光谱能量值和在5种不同极性溶剂中的偶极矩,并讨论了三种异构体偶极矩变化和溶剂极性变化对n→π*跃迁的吸收光谱移动的影响.

Based on the new electrostatic solvation energy expression of the nonequilibrium state by means of dielectric continuum theory and constrained equilibrium method,a novel formula for the absorption/emission spectral shift is deduced within the dipole-in-a-sphere approximation.The absorption spectra in the n → π＊ electronic transition of three tautomers：pyridazine,pyrimidine and pyrazine in vacuum and the dipole moments of the tautomers in five polar solvents are calculated at the level of CASSCF（6,5）/6-31 ＋＋G＊＊.The variation tendency of the blue shifts in the n → π＊ transition,due to the variational dipole moments of solutes and polarities of solvents,is discussed.