关键词: 邻苯二甲酸二辛酯/
外电场/
密度泛函理论/
紫外-可见光谱
English Abstract
Investigation of external electric field effect on C24H38O4 molecule by density functional theory
Du Jian-Bin1,2,Zhang Qian1,
Li Qi-Feng2,
Tang Yan-Lin3
1.College of Physics and Electrical Information, Langfang Normal University, Langfang 065000, China;
2.College of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072, China;
3.Department of Physics, Guizhou University, Guiyang 550025, China
Fund Project:Project supported by the National Key Research and Development Program of China (Grant Nos. 2014YQ060773, 2017YFC0803600), the Young Fund of Hebei Education Department, China (Grant No. QN2015219), and the Natural Science Foundation of Langfang Normal University, China (Grant No. LSLY201509).Received Date:12 September 2017
Accepted Date:01 February 2018
Published Online:20 March 2019
Abstract:The C24H38O4 (dioctyl phthalate, DOP) is a main component of the plasticizer. In order to study the influence of external electrical field on molecular structure and spectrum of DOP, the method B3LYP of the density functional theory at B3LYP/6-311G(d,p) level is employed to calculate geometrical parameters of the ground state of DOP molecule under different external electric fields (from 0 to 0.0125 a.u.) in this article. On this basis, the ultraviolet-visible absorption spectrum of DOP is calculated by using the time-dependent density functional theory in the same fundamental group and compared with the ultraviolet absorption peak of the molecules, measured by UNICO ultraviolet and visible spectrophotometer. Finally, by using the time-dependent density functional theory in the same fundamental group, we study wavelengths and oscillator strengths of the first twenty-six excited states of DOP molecule in external electric field. The obtained results are as follows. The strongest absorption of ultraviolet-visible absorption spectrum appears in the end absorption band from n to σ* transition. The stronger absorption occurs in the E band of benzene electronic transition from π to π*. The molecular geometry parameters are strongly dependent on the external field intensity. The dipole moment of DOP molecule is proved to first decrease and then increase with the sharp increase of external field, but the total energy first increases and then decreases with the increase of the external field intensity. The ultraviolet absorption peaks of excited states of DOP are proved to have observably red shift, and the oscillator strength sharply decreases with the increasing of the field intensity.
Keywords: C24H38O4/
external electric field/
density functional theory/
ultraviolet-visible spectrum
