电子给受体复合物中电荷转移吸收光谱和溶剂效应

Charge Transfer Absorption and Solvent Effects in Electron Donor-Acceptor Complex

用MP2 / 6 3 1G 方法研究了二氯甲烷溶剂分子与电子给体、受体以及电子给受体复合物间的相互作用 ,结果表明 ,二氯甲烷与电子受体和电子给受体复合物间有弱氢键相互作用 .利用CIS/ 6 3 1++G 方法研究了溶剂与溶质分子间形成氢键对激发态的影响 .自然键电荷分析表明 ,电子给受体复合物的S0 →S1跃迁导致一个电子从电子给体转移到受体 .结合非平衡溶剂化处理和自洽反应场方法研究了溶剂分子与复合物间形成氢键时的电荷转移吸收光谱 .

Mller-Plesset second order perturbation calculations for the interaction between the solvent molecule and solute were performed. The theoretical calculations showed that there existed weak hydrogen bonding interaction between the solvent molecule and the cyano group of tetracyanoethylene. CIS calculations and natural bond orbital charge population analysis indicated that the photoexcitation of the electron donor acceptor complex would lead to a charge transfer absorption, and the hydrogen bonding effect yielded a blue shift of this absorption. The equilibrium solvation energy was evaluated by self-consistent reaction field method, and nonequilibrium solvation was considered in the prediction of absorption spectrum.