Wakamiya Atsushi, Mori Kenji, Araki Takafumi, Yamaguchi Shigehiro
Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.
J Am Chem Soc. 2009 Aug 12;131(31):10850-1. doi: 10.1021/ja905007s.
As a B-B bond-containing polycyclic pi-electron system, a dithieno3,2-c:2',3'-e derivative and its dianion salts were successfully prepared, and their structures were determined by X-ray crystallography. The neutral dithieno-1,2-dihydro-1,2-diborin has a twisted diborin ring in which both the sigma-pi and p-pi* orbital interactions between the bithiophene pi framework and the B-B bond moiety effectively take place, giving rise to an absorption that is significantly red-shifted compared with that of the parent bithiophene. Upon a two-electron reduction, the dithienodiborin pi framework becomes planar and has a characteristic peripheral pi conjugation through the B-B bond with 14 pi electrons. Furthermore, the dianion salts show an intriguing countercation effect on their photophysical properties, indicative of possible electronic tuning by the countercations.
作为一种含B-B键的多环π电子体系，成功制备了二噻吩并3,2-c:2',3'-e衍生物及其二价阴离子盐，并通过X射线晶体学确定了它们的结构。中性的二噻吩-1,2-二氢-1,2-二硼具有扭曲的二硼环，其中联噻吩π骨架与B-B键部分之间的σ-π和p-π*轨道相互作用有效地发生，导致吸收峰相对于母体联噻吩发生显著红移。经过双电子还原后，二噻吩二硼π骨架变得平面化，并通过具有14个π电子的B-B键具有特征性的周边π共轭。此外，二价阴离子盐对其光物理性质表现出有趣的抗衡阳离子效应，表明抗衡阳离子可能进行电子调谐。
