Structures and binding energies of the (dibenzoylmethanato)boron difluoride complexes with aromatic hydrocarbons in the ground and excited states. Density functional theory calculations

Structures of the (dibenzoylmethanato)boron difluoride molecule (DBMBF2) and its complexes with a series of aromatic hydrocarbons (benzene; toluene; o-, m-, and p-xylenes, naphthalene; anthracene; and pyrene) in the ground and the first singlet excited states have been calculated. The calculations have been performed by the density functional theory (DFT) and time-dependent density functional theory (TDDFT) for the ground and excited states, respectively, with the empirical dispersion correction. It has been shown that the complexes in the ground and excited states have similar stacking structures and are characterized by short contacts between the F atom of DBMBF2 and H atoms of the hydrocarbon molecule, which decrease on transition from the ground to the excited state. The calculated binding energies in the complexes in the excited state are two to three times higher than those in the ground state. The charge transfer in the ground state of the complexes is insignificant and directed from DBMBF2 to the ligand, while in the excited state it is 0.6–0.8 e and directed from the ligand to DBMBF2.