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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (14): 1443-1448. 上一篇    下一篇

研究论文

含四硫富瓦烯Schiff碱配体和配合物二阶非线性光学性质的密度泛函理论研究

刘艳，仇永清*，孙世玲，赵海波，苏忠民   

  1. (东北师范大学化学学院 功能材料化学研究所 长春 130024)
  • 投稿日期:2009-07-16 修回日期:2009-09-24 发布日期:2010-03-25
  • 通讯作者: 仇永清 E-mail:qiuyq466@nenu.edu.cn
  • 基金资助:

    国家自然科学基金(No.20873017)

Density Functional Theory Study On Second-order Nonlinear Optical Properties of Tetrathiafulvalene-Fused Schiff Base Ligand and Complexes

LIU Yan, CHOU Yong-Qing, SUN Shi-Ling, ZHAO Hai-Bo, SU Zhong-Min   

  1. (Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024)
  • Received:2009-07-16 Revised:2009-09-24 Published:2010-03-25
  • Contact: Qiu Yong-Qing E-mail:qiuyq466@nenu.edu.cn

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被引次数

18 | 5

采用密度泛函理论(DFT) B3LYP(UB3LYP)/6-31g*方法对含四硫富瓦烯Schiff碱配体和它的Fe(III/II), Co(II), Ni(III/II), Cu(II)配合物的极化率和二阶非线性光学(NLO)性质进行了研究, 并对其中闭壳层分子采用含时密度泛函理论(TD-DFT)方法计算了电子光谱. 结果表明: 含四硫富瓦烯Schiff碱配体本身具有较大的二阶NLO系数, 二价金属配合物二阶NLO系数与配体接近, 三价金属配合物二阶NLO系数约为配体的30倍. 金属配合物不同自旋多重度时其二阶NLO系数相差不大. 结合配体和配合物的前线分子轨道分析可知, 配体和二价金属配合物的二阶NLO系数主要是配体内的电荷转移(ILCT)的贡献, 三价金属配合物既有ILCT又有金属与配体间电荷转移(MLCT), 同时前线分子轨道能级差显著减小, 因此它们的二阶NLO系数显著增大.

关键词: 四硫富瓦烯Schiff碱, 金属配合物, 二阶NLO性质, DFT

The density functional theory (DFT) B3LYP(UB3LYP) method based on the 6-31g* level was employed to investigate the polarizabilities and second-order nonlinear optical (NLO) properties of tetrathiafulvalene-fused Schiff base ligand and its Fe(III/II), Co(II), Ni(III/II), Cu(II) complexes. The electronic spectra of closed-shell complexes were analyzed by the time-dependent density functional theory (TD-DFT) method. The results show that tetrathiafulvalene-fused Schiff base ligand possess considerable large second-order NLO coefficient and divalent metal complexes are close to that of the ligand. While for trivalent metal complexes, the β values increase to 30 times as large as that of ligand. The β values in different spin multiplicity of metal complexes are differ little. Combined with the composition of frontier molecular orbitals, the second-order NLO coefficients of ligand and divalent metal complexes are mainly related to the intraligand charge transfer (ILCT) process. While the trivalent metal complexes are assigned to an ILCT transition and combined with an MLCT (metal-to-ligand charge transfer) transition, meanwhile, the frontier molecular orbitals energy gap of the trivalent metal complexes are significantly decreased, thus lead to enhance their second-order NLO coefficients.

Key words: tetrathiafulvalene-fused Schiff base, metal complexes, second-order NLO properties, DFT