Electronic structure of laser dye DCM and its derivatives

Abstract

AbstractThe electron energetic characteristics of laser dye molecules 4‐dicyanomethylene‐2‐methyl‐6‐p‐dimethylamino‐styryl‐4H‐pyran (DCM), (E)‐2‐{2‐[2‐(4‐dimethylaminophenyl)ethynyl]‐6‐threefluoromethyl‐4H‐4‐pyranylidene}‐malonitrile (DCMF3), (E)‐2‐{2‐[2‐(4‐dimethylaminophenyl)ethynyl]‐6‐n‐heptafluoropropyl‐4H‐4‐pyranylidene}‐malonitrile (DCMF7), (E)‐2‐{2‐[2‐(5‐piperidine‐2‐thienyl)ethynyl]‐6‐threefluoromethyl‐4H‐4‐pyranylidene}‐malonitrile (PTFDN) were investigated thoroughly using semiempirical methods ZINDO/1 and ZINDO/S. The geometry optimization was carried out by the method of conjugated gradients. On the basis of the electronic structure and optimum geometry of the molecules, the spectra of electronic transitions to the excited states, the dipole moments, and oscillator strengths of the transitions were calculated by the method of configuration interaction. Typical features of the electronic absorption spectra of these molecules were calculated and compared with the experimental data. The influence of the solvent on the optical absorption spectra was explored. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005