The study of nonresonant Raman excited virtual state of carbazole molecule

Abstract

According to the relationship between Raman intensity and the bond polarizability, we investigate the temporal bond polarizabilities of carbazole molecule from the Raman intensities. We obtain the bond polarizability of the final state and compare it with the electronic density of the ground state by the density functional theory method, then we discuss and analyze the characteristics of carbazole temporal bond polarizabilities. The results show that at the initial stage of exitation, the excited electrons tend to flow toward the bond that we called connecting bond, which connects the two six-member ring, but not toward the molecular periphery. The bond electronic density of the molecule ground state can be mapped out by the temporal bond polarizabilities at the final stage of relaxation, therefore we conclude that the excited electrons flow back to the skeleton bond. Furthermore, we find the relaxation characteristic time of connecting the bonds is longer than that of connecting the other bonds, this further confirms our observations mentioned above. These conclusions will improve our understanding of Raman excited virtual states of the molecule with the bridge bonds.