Theory Study On The Optical Properties Of Dyes Containing Benzophenone Moiety

Along the information age coming, nonlinear optics has become an important branch of modern science. It has become an important project to find new nonlinear optical materials, due to their wide use and attractive application foreground in high-speed optical Communication, optical information processing and optoelectronics fields.The thesis mainly aims to theoretically study the linear and nonlinear optical properties of organic molecules and to investigate the structure-property-relation of molecules. In order to offer theoitial references in synthesizing compounds with stronger nonlinear optical properties, present study can be summarized as following two parts:1. Non-conjugated system four compouds have typical D-π-A structure. Molecular geometries were optimized using HF (Hartree-Fock) method, hybrid density functional theory (DFT) B3LYP and CIS (single-excitation configuration interaction) and their transition dipole moment, excited state energy, absorbed and emission spectra were calculted with time-dependent density functional theory. It indicates that TPA cross sections of organic conjugated molecules are related to the molecule length, the property of theπcenter, and the strength of the substitutions, the substitutions'symmetry and molecular dimension. Therefore, studing one-photon predict the nature of the molecular two-photon.2. whole conjugated system of four compouds have a long conjugcy, the optical properties of molecule in the ground and excited states were calculated by the same method of total non-conjugated system. The results indicate that compared with non-conjugated system the system has obvious red shift in absorption and emission spectra.