Title
Cooperative Effects of o- and m-Methyl Groups on the Intramolecular Charge-Transfer Emission Properties of Dibenzoylmethanatoboron Difluorides
Author
Mirai Tanaka, Shunsuke Muraoka, Yasunori Matsui, Eisuke Ohta, Takuya Ogaki, Kazuhiko Mizuno, Hiroshi Ikeda
Year
2017
Journal
Photochemical & Photobiological Sciences
Abstract
The photophysical properties of o-tolyl-, m-tolyl-, and p-xylyl-substituted asymmetric diaroylmethanatoboron difluorides in a mixture of CH2Cl2 and c-C6H12, and in the crystalline state were determined. In solution, the fluorescence (FL) properties of these substances are controlled by the position and number of methyl groups on the phenyl rings. An especially interesting finding is that FL from the p-xylyl derivative occurs from an excited state which possesses intramolecular charge-transfer character caused by the o- and m-methyl groups cooperatively. The results of X-ray crystallographic analysis reveal that these asymmetric diaroylmethanatoboron difluorides form dyads through orbital overlap of neighboring molecules. This phenomenon governs the unique FL properties of these substances in the solid state.
Instrument
FP-8500
Keywords
Fluorescence, Chemical stability, Materials