Perylene and terrylene in rare gas matrixes: spectroscopic and computational studies of inclusion sites

The low-temperature (20 K) electronic absorption and emission spectra of terrylene (C30H16) and perylene (C20H12) isolated in Kr and Xe matrixes are presented. The spectra of both chromophores in Kr matrix reveal similar multiplet structure, and in each spectrum, six different sites were identified. In order to understand the origin of observed site—splitting, the theoretical calculations of complex system—chromophore embedded into Kr matrix—were carried out by means of MM+ method. The optimization of system structure yielded six different types (sites) of embedding chromophore molecules into Kr crystal lattice. As calculations have shown, the nearest environment of each site distinguishes by its specific density of rare gas atoms, on which basis the relationship between theoretically calculated sites and observed spectral features was established.