Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (09): 1867-1873.doi: 10.3866/PKU.WHXB20090910

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Second-Order Nonlinear Optical Properties of a Series of Y-Shaped Organic Molecules with a Thiazole Chromophore

LUO Shan-Shan, QIU Yong-Qing, LIU Xiao-Dong, LIU Chun-Guang, SU Zhong-Min   

  1. Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun 130024, P. R. China
  • Received:2009-04-07 Revised:2009-06-03 Published:2009-09-03
  • Contact: QIU Yong-Qing E-mail:qiuyq466@nenu.edu.cn

Abstract:

Density functional theory (DFT) B3LYP/6-31G* method was employed to optimize the structures of a series of Y-shaped organic heterocyclic molecules containing a thiazole chromophore. Based on the obtained stable molecular configuration, we adopted the finite field (FF) method and time-dependent density-functional theory (TD-DFT) to calculate and analyze the nonlinear optical (NLO) properties and electric spectra of these molecules. Results show that the molecules possess A-π-D-π-A (A: acceptor, D: donor) structures, and the dipole moment of the ground state, the polarizability, and the second-order NLO coefficient (β) of the molecules increase with increase of the length of conjugate bridge of the branched chain and the conjugation effect of the chromophore. The total virtual value of second-order polarizability (βtot) of the series of organic heterocyclic molecules was found to be related to the energy gap of the frontier molecular orbital. The molecule with smaller energy gap of the frontier molecular orbital shows larger values of βtot.

Key words: Density functional theory, Y-shaped organic molecule, Thiazole chromophore, Second-order nonlinear optical property

MSC2000: 

  • O641