Computation of Electronic Absorption Spectra and Spectral Properties of Neutral 1-Methyl Chrysene and Its Positive Ion in H3BO3 Matrix by AM1 and PM3 Methods

Abstract

The theoretical electronic absorption spectrum of methyl chrysene, a polycylic aromatic hydrocarbon in boric acid matrix, is calculated for the first time, using semi-empirical method. Earlier reported theoretical results of electronic spectrum were calculated in free state and the results compared with the spectrum of aromatic system in glassy or other matrices. The interaction between the trapped polycyclic aromatic hydrocarbons (neutral and ions) and its environment induces perturbations of the energy levels which results in large shifts of the electronic transitions as compared to isolated polycyclic aromatic hydrocarbon molecule.The spectroscopic and electronic parameters have been reported, using semi empirical methods, for the present probe in free, aqeuous and H₃BO₃ matrix. The static polarizability values have also been calculated to check the Laser action of the 1-methyl chrysene and its cation.