Theoretical study on stability and nonlinear optical properties of tetrahydropyrrole diradical and its isoelectronic systems in different electronic states  

作　　者：SUN XiaoNa QIU YongQing SUN ShiLing LIU ChunGuang DU YanQing SU ZhongMin 

机构地区：[1]Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, China

出　　处：《Science China Chemistry》2011年第7期1086-1093,共8页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (20873017);the Program for Changjiang Scholars and Innovative Research Teams in University (IRT0714)

摘　　要：The polarizabilities and hyperpolarizabilities of the tetrahydropyrrole diradical in different electronic states have been investigated using ab initio and density functional theory （DFT） methods combined with the finite field （FF） approach. The polarizability average value as is a maximum for the singlet state, while that for the closed-shell is a minimum. The trend in second hyperpolarizability average value yis in good agreement with that for as The yvalues of the singlet and triplet states are, respectively, about 3 and 2 times larger than that of the closed-shell. The order of the first hyperpolarizability total effective value βtot is βot （closed shell） βtot （singlet） 〉 βtot （triplet）. The as, βtot, and 7 values of different electronic states obtained using the B3LYP and MP4SDQ methods are close to those obtained using the reliable CCSD method. The nonlinear optical （NLO） properties of two systems isoelectronic with the tetrahydropyrrole diradical-cyclopentane and tetrahydrofuran diradicalsshow that the polarizabilities and hyperpolarizabilities of these systems are all smaller than those of the tetrahydropyrrole diradical in the three electronic states.The polarizabilities and hyperpolarizabilities of the tetrahydropyrrole diradical in different electronic states have been investigated using ab initio and density functional theory(DFT) methods combined with the finite field(FF) approach.The polarizability average value αs is a maximum for the singlet state,while that for the closed-shell is a minimum.The trend in second hyperpolarizability average value γ is in good agreement with that for αs.The γ values of the singlet and triplet states are,respectively,about 3 and 2 times larger than that of the closed-shell.The order of the first hyperpolarizability total effective value βtot is βtot(closed-shell) > βtot(singlet) > βtot(triplet).The αs,βtot,and γ values of different electronic states obtained using the B3LYP and MP4SDQ methods are close to those obtained using the reliable CCSD method.The nonlinear optical(NLO) properties of two systems isoelectronic with the tetrahydropyrrole diradical - cyclopentane and tetrahydrofuran diradicals - show that the polarizabilities and hyperpolarizabilities of these systems are all smaller than those of the tetrahydropyrrole diradical in the three electronic states.

关 键 词：RADICAL electronic state isoelectronic system NLO properties 

分 类 号：O641.4[理学—物理化学] TQ251.3[理学—化学]