Obeid Naim M, Klemmer Lukas, Maus Daniel, Zimmer Michael, Jeck Jonathan, Bejan Iulia, White Andrew J P, Huch Volker, Jung Gregor, Scheschkewitz David
Krupp-Chair of General and Inorganic Chemistry, Saarland University, 66123 Saarbrücken, Germany.
Dalton Trans. 2017 Jul 11;46(27):8839-8848. doi: 10.1039/c7dt00397h.
A series of aryl disilenes TipSi[double bond, length as m-dash]Si(Tip)Ar (2a-c) and para-arylene bridged tetrasiladienes, TipSi[double bond, length as m-dash]Si(Tip)-LU-Si(Tip)[double bond, length as m-dash]SiTip (3a-d) are synthesized by the transfer of the TipSi[double bond, length as m-dash]SiTip unit to aryl halides and dihalides by nucleophilic disilenides TipSi[double bond, length as m-dash]SiTipLi (Tip = 2,4,6-iPrCH, Ar = aryl substituent, LU = para-arylene linking unit). The scope of the nucleophilic Si[double bond, length as m-dash]Si transfer reaction is demonstrated to also include substrates of considerable steric bulk such as mesityl or duryl halides Ar-X (Ar = Mes = 2,4,6-MeCH; Ar = Dur = 2,3,5,6-MeCH, X = Br or I). Bridged tetrasiladienes TipSi[double bond, length as m-dash]Si(Tip)-LU-Si(Tip)[double bond, length as m-dash]SiTip with more extended linking units surprisingly exhibit fluorescence at room temperature, albeit weak. DFT calculations suggest that partial charge transfer character of the excited state is a possible explanation.
通过亲核二硅化物TipSi═SiTipLi（Tip = 2,4,6 - iPr₃C₆H₂，Ar = 芳基取代基，LU = 对亚芳基连接单元）将TipSi═SiTip单元转移至芳基卤化物和二卤化物上，合成了一系列芳基二硅烯TipSi═Si(Tip)Ar（2a - c）和对亚芳基桥连的四硅二烯TipSi═Si(Tip)-LU-Si(Tip)═SiTip（3a - d）。亲核Si═Si转移反应的范围被证明还包括具有相当大空间位阻的底物，如均三甲苯基或连四甲苯基卤化物Ar - X（Ar = Mes = 2,4,6 - Me₃C₆H₂；Ar = Dur = 2,3,5,6 - Me₄C₆H₂，X = Br或I）。具有更长连接单元的桥连四硅二烯TipSi═Si(Tip)-LU-Si(Tip)═SiTip在室温下出人意料地表现出荧光，尽管很微弱。密度泛函理论计算表明，激发态的部分电荷转移特性可能是一种解释。
