Tanaka Mirai, Muraoka Shunsuke, Matsui Yasunori, Ohta Eisuke, Ogaki Takuya, Mizuno Kazuhiko, Ikeda Hiroshi
Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Photochem Photobiol Sci. 2017 Jun 14;16(6):845-853. doi: 10.1039/c7pp00005g.
The photophysical properties of o-tolyl-, m-tolyl-, and p-xylyl-substituted asymmetric diaroylmethanatoboron difluorides in a mixture of CHCl and c-CH, 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.
测定了邻甲苯基、间甲苯基和对二甲苯基取代的不对称二芳酰甲烷基硼二氟化物在CHCl和c-CH混合物中以及晶体状态下的光物理性质。在溶液中，这些物质的荧光（FL）性质受苯环上甲基的位置和数量控制。一个特别有趣的发现是，对二甲苯基衍生物的FL来自一种激发态，该激发态具有由邻位和间位甲基协同作用引起的分子内电荷转移特性。X射线晶体学分析结果表明，这些不对称二芳酰甲烷基硼二氟化物通过相邻分子的轨道重叠形成二元组。这种现象决定了这些物质在固态下独特的FL性质。
