Substituent influence on the spectra of some benzo[f]quinoline derivatives

Abstract

The aim of this study was to investigate the relations between the properties of some organic compounds that are cycloaddition derivatives of benzo[f]quinoline, namely benzo[f]pyrrolo[1,2-a]quinolines (BQCDs) and the structure of variable substituent in the addition cycle. The work was focused on the differences in the molecular parameters like frontier orbitals and dipole moment as well as electronic absorption spectra of substituted BQCDs.The optimized molecular structures of BQCDs were calculated using Gaussian 09, with DFT method, the frontier orbitals and electronic absorption spectra being modeled with restricted Hartree Fock method also implemented in Gaussian 09. Influence of substituted radical on the dipole moments and frontier orbital energies of the BQCDs was evidenced from calculated values. Substituent effect on the BQCDs recorded electronic absorption spectra in diluted solution and protonated diluted solution was also emphasized: different types of the transitions underlying absorption bands in the visible range were presumed based on the quantum chemical and experimental investigation.