Abstract
Abstract Using the method of density functional theory in approximating B3LYP with the basis set 6‐31G(d) the computations of structures of the following dyes 2,2′‐N‐N′‐di(1,3‐diisopropylbenzene)‐diimide 3,4,9,10‐perylenetethracarbon acid (Perylene Orange‐PO) and 1,6,7,12‐tethraphenyl ether 2,2′‐N,N′‐di(1,3‐diisopropylbenzene)‐diimide 3,4,9,10‐perylenetethracarbon acid (Perylene Red‐PR) were performed. It was revealed that PO and PR have nonplanar structures. On the basis of the predicted geometrical structures and molecular orbitals of S0 ground state their theoretical UV‐vis spectra, which are in good agreement with experiment, were obtained by applying time‐dependent DFT (TDDFT) method. In addition, the calculations of complex [PR … NaN3] and its UV‐vis spectrum, which was compared with the observed electron spectrum of PR ethanol solution in the presence of NaN3 under the laser irradiation at 532 nm, were carried out. By using DFT method at B3LYP level the calculations of the assumed complex were made where the reaction coordinate was the distance between Na+ and carbonyl group O atom. It was suggested that [PR … NaN3] complex formation involves transition of PR to the triplet state which brings about formation of PR anion. New peak at 793 nm in UV‐vis spectrum of this solution under the laser irradiation at 532 nm is supposed to be a PR anion band. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007