N—甲基—吡咯烷并[3,4]C60衍生物的结构、电子光谱和二阶非线性光学性质的理论研究  

Theoretical Investigation on Electronic Spectra and Second-orderNonlinear Optical Properties of N - Methyl - pyrrolo[3,4]C60 Derivatives

作　　者：刘永军[1] 刘英[2] 刘成卜[3] 

机构地区：[1]曲阜师范大学化学系,山东大学理论化学研究所 [2]曲阜师范大学化学系, [3]山东大学理论化学研究所,

出　　处：《化学学报》2001年第6期906-912,共7页Acta Chimica Sinica

基　　金：国家自然科学基金

摘　　要：利用半经验AM1量子化学方法研究了N-甲基-吡咯烷并[3,4]C60(MPC)及其噻吩取代衍生物(TMPC)的几何结构.电子结构研究表明,MPC及TMPC衍生物的前沿轨道主要由G60部分决定,C60母体与加成基团之间存在较强的分子内电荷转移,C60部分是电子受体,而噻吩环部分和吡咯环部分为电子给体.在AM1优化几何构型的基础上,用INDO/SCI方法计算了MPC及TMPC的电子光谱,用完全态求和(SOS)公式计算了其二阶非线性光学性质.结果表明,MPC与TMPC在400 nm以上均存在吸收峰,TMPC的这些吸收峰(400 nm以上)比MPC的吸收峰强得多,与实验所得结果一致.对于TMPC来说,其二阶非线性光学系数β0值随分子构型的不同而有较大的变化,β0值最大可达60×10-30esu.By using AM1 semiempirical quantum calculation method, the structures and electronic properties of N - methyl - pyrmlo[3,4] C-60(MPC) and N - methyl - 2 - (2 ' - dimethylaniline - substituted dithienylenthylene) - pyrrolo[3,4] C-60(TMPC) have been studied. The frontier molecular orbitals of the C60 moiety dominate those of MPC and TMPC. For MPC and TMPC, there exists strong intramolecular electron transfer. The C60 moiety is electron acceptor while the thiophene and pyrrolidine parts are electron donor, Based on the AM1 optimizing geometry, the electronic spectra and second - order nonlinear optical polarizabilities (beta) of TMPC and MPC are calculated by using INDO/SCI method combined with sum - over - states (SOS) expression. The calculated results reveal that there exist absorption peaks above 400 nm both for TMPC and MPC and those of TMPC are much stronger than those of MPG. For TMPC, beta values vary with different isomers.

关 键 词：N-甲基-吡咯烷并[3 4]碳60衍生物 富勒烯衍生物 结构 电子光谱 二阶非线性光学性质 AI1 INDO/SCI 

分 类 号：O635.1[理学—高分子化学] O621.13[理学—化学]