Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (08): 1847-1853.doi: 10.3866/PKU.WHXB20110840

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

Density Functional Theory Study on Vinyl Thiophene Group Conjugated Spirooxazines

SUN Hai-Tao1, TIAN Xiao-Hui1, YUAN Yi-Zhong1, SUN Jin-Yu1, SUN Zhen-Rong2, ZHUO Xiao-Ling1   

  1. 1. Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China;
    2. State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
  • Received:2011-04-21 Revised:2011-05-18 Published:2011-07-19
  • Contact: TIAN Xiao-Hui E-mail:tianxh@263.net
  • Supported by:

    The project was supported by the National High Technology Research and Development Program of China (0099AA03500), Shanghai Leading Academic Discipline Project (B502) and Shanghai Key Laboratory Project, China (08DZ2230500, 09JC1404300).

Abstract:

We carried out a theoretical study on the geometries, electronic structures, and frontier molecular orbitals of vinyl thiophene group conjugated spirooxazines (SO-SO3) using density functional theory (DFT) at the B3LYP/6-31G* level. The calculated results show that the equalization of bond lengths at the left and right parts of the open-forms occurred during the ring-opening process. A large conjugated system was formed and this significantly narrowed the energy gap. The conjugated system became larger and its electrons flowed easily because of the introduction of different lengths of vinyl thiophene conjugation moieties into the spirooxazine molecule. The electrons and energy efficiently transferred from the vinyl thiophene to naphthoxazine. The orbital contribution rate of the vinyl thiophene group in the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) increased obviously. Time-dependent DFT (TD-DFT) calculations showed that as the conjugated vinyl thiophene unit reached 2-3 the first singlet excited state of SO2 and SO3 resulted from the electron transition from the HOMO to the LUMO, which were also assigned to the π* transition. Meanwhile, λmax was between 466 and 540 nm with an obvious red-shift while the λmax of O-SO2 and O-SO3 reached 605 and 647 nm, respectively.

Key words: Vinyl thiophene, Spirooxazine, Density functional theory, Frontier molecular orbital, Electronic absorption spectrum

MSC2000: 

  • O641