溶剂对2-(N-甲基)氨基-5-硝基吡啶光学性质的影响  

Effect of Solvent on Optical Properties of 2-(N-Nethyl)Amino-5-Nitropyridine Molecule

作　　者：黄志敏[1] 韩奎[1] 李海鹏[1] 逯振平[1] 张文涛[1] 唐刚[1] 

机构地区：[1]中国矿业大学理学院,江苏徐州221116

出　　处：《中国矿业大学学报》2007年第6期858-863,共6页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(10674177);中国矿业大学科技基金项目(2006B025)

摘　　要：基于自洽反应场(SCRF)中的极化连续介质模型(PCM),采用从头算HF/6-31G方法优化了标题分子2-(N-甲基)氨基-5-硝基吡啶在不同溶剂中的几何结构,采用含时密度泛函方法,在B3LYP理论水平下,利用6-31+G(d,p)基组,计算了不同溶剂中该分子的紫外吸收光谱.系统研究了溶剂对2-(N-甲基)氨基-5-硝基吡啶分子的构型、紫外吸收光谱和非线性光学(NLO)性质的影响.结果表明:随着溶剂相对介电常数rε的增大,2-(N-甲基)氨基-5-硝基吡啶分子电偶极矩、线性极化率和第一超极化率都增大,并且在rε>10后,溶剂对分子构型、分子NLO性质以及分子吸收峰的影响趋于平缓.此外,氢键对分子NLO性质的影响较大,但PCM模型不能较好的描述这种氢键作用.Ab initio calculation has been performed to study the nonlinear optical （NLO） properties of 2-（N-methyl） amino-5-nitropyridine molecule. Based on the polarized continuum model（PCM） of the self-consitent reaction field（SCRF） theory, the geometrical structures of 2-（N- methyl） amino-5-nitropyridine molecule in gas and different solvents were optimized by HF/6- 31G method. The ultraviolet spectra were calculated using time dependent density functional theory on the basis of B3LYP/6-31＋G（d,p） method. The effects of solvents on the geometrical structures, ultraviolet spectra and NLO properties of 2-（N-methyl） amino-5-nitropyridine molecule were studied. The results show that with the increasing of the solvent dielectric constant, the dipole moment, polarizabilities and first-order nonlinear hyperpolarizabilities increase rapidly, then increase slowly at εr〉10. In addition, the effect of hydrogen bonding on the NLO properties of 2-（N-methyl） amino-5-nitropyridine molecule is significant. But the PCM model can not obviously describe hydrogen bonding effects well.

关 键 词：极化连续介质模型(PCM) 溶剂效应 第一超极化率 氢键作用 

分 类 号：O641.3[理学—物理化学] O437[理学—化学]