Perylene complexes with p-dichlorobenzene and related species: comparison of rotational coherence data with structure calculations

Rotational coherence experiments have been carried out on complexes of perylene with p-dichlorobenzene (DCB), p-difluorobenzene (DFB) and hexafluorobenzene, largely to seek an explanation for the unusually small complexation shifts of the first two. All three complexes were found to have overlapped, parallel ring structures, similar to that of perylene/benzene. Moreover, in structures corresponding to the electronic ground state, the halogen-halogen axes of DFB and DCB were found to be aligned perpendicular to the perylene long axis.