Chinese Journal of Applied Chemistry ›› 2017, Vol. 34 ›› Issue (12): 1474-1480.DOI: 10.11944/j.issn.1000-0518.2017.12.170156

• Full Papers • Previous Articles    

Density Functional Theory Research on the Optical Properties of Thiazole Orange Cyanine Dyes

CAO Jianfanga*(),FAN Jianglib*(),GUO Yua,WU Hongmeia   

  1. aSchool of Chemical and Environmental Engineering,Liaoning University of Technology,Jinzhou,Liaoning 121001,China
    bState Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian,Liaoning 116024,China
  • Received:2017-05-15 Accepted:2017-06-28 Published:2017-12-04 Online:2017-12-04
  • Contact: CAO Jianfang,FAN Jiangli
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.21606118, No.21601075), the Natural Science Foundation of Liaoning Province(No.2015020249), the Open Project Fund of State Key Laboratory of Fine Chemicals(No.KF1614)

Abstract:

4-(Diethylamino)butyl substituted trimethylthiazole orange(DEAB-TO3) is essentially nonfluorescent in aqueous solution, which can be used to detect nucleic acids in cells. The spectroscopic properties of 4-(two ethyl amino) butyl substituted methyl thiazole orange(DEAB-TO1) and DEAB-TO3 were studied by density functional theory method. The geometry optimization of the ground state and the excited state reveal highly distorted configuration of the excited state. Spectral analysis and orbital analysis show that the first excited state is a dark state with twisted intermolecular charge transfer. The ground state and the excited state potential energy curves show that DEAB-TO1 and DEAB-TO3 have very low energy gap and rotational energy barrier. These results explain their low background fluorescence.

Key words: density functional theory, thiazole orange dyes, geometry optimization, spectrum calculation, potential energy curvesn