Molecular design and luminescence of boron difluoride benzoylacetonates

Two groups of compounds differing in the crystal supramolecular architecture and luminescence properties have been identified in a series of boron difluoride benzoylacetonates. In the case of the first group, the luminescence spectra of saturated solutions are bathochromically shifted relative to those of crystals. Molecules of the compounds of the first group are organized into infinite stacks with just one type of overlapping. The quantum-chemistry simulation demonstrates that the geometry of dimers in a crystal, unlike that in saturated solutions is not optimal. J-aggregates composed of dimers of the geometry similar to the optimal one are formed in crystals of the compounds of the second group. The luminescence spectra of saturated solutions and crystals of the second group compounds are identical.