Guan Jun, Sun Zejun, Ansari Ramin, Liu Yujia, Endo Aimi, Unno Masafumi, Ouali Armelle, Mahbub Shahrea, Furgal Joseph C, Yodsin Nuttapon, Jungsuttiwong Siriporn, Hashemi Daniel, Kieffer John, Laine Richard M
Department of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109-2136, USA.
Department of Chemistry, National University of Singapore, Singapore, 117549, Singapore.
Angew Chem Int Ed Engl. 2021 May 10;60(20):11115-11119. doi: 10.1002/anie.202014932. Epub 2021 Apr 8.
Multiple studies have explored using cage silsesquioxanes (SQs) as backbone elements in hybrid polymers motivated by their well-defined structures and physical and mechanical properties. As part of this general exploration, we report unexpected photophysical properties of copolymers derived from divinyl double decker (DD) SQs, [vinyl(Me)Si(O ) ][PhSiO ] [(O ) Si(Me)vinyl] (vinylDDvinyl). These copolymers exhibit strong emission red-shifts relative to model compounds, implying unconventional conjugation, despite vinyl(Me)Si(O-) siloxane bridges. In an effort to identify minimum SQ structures that do/do not offer extended conjugation, we explored Heck catalyzed co-polymerization of vinyl-ladder(LL)-vinyl compounds, vinyl(Me/Ph)Si(O ) [PhSiO ] (O ) Si(Me/Ph)vinyl, with Br-Ar-Br. Most surprising, the resulting oligomers show 30-60 nm emission red-shifts beyond those seen with vinylDDvinyl analogs despite lacking a true cage. Further evidence for unconventional conjugation includes apparent integer charge transfer (ICT) between LL-co-thiophene, bithiophene, and thienothiophene with 10 mol % F TCNQ, suggesting potential as p-type doped organic/inorganic semiconductors.
多项研究探讨了使用笼型倍半硅氧烷（SQs）作为杂化聚合物的主链元素，这是受其明确的结构以及物理和机械性能的驱动。作为这一总体探索的一部分，我们报告了由二乙烯基双层（DD）SQs，即[乙烯基（甲基）硅（氧）][苯基硅氧][（氧）硅（甲基）乙烯基]（乙烯基DD乙烯基）衍生的共聚物出人意料的光物理性质。尽管存在乙烯基（甲基）硅（氧-）硅氧烷桥，但这些共聚物相对于模型化合物表现出强烈的发射红移，这意味着存在非常规的共轭作用。为了确定能提供/不能提供扩展共轭作用的最小SQ结构，我们探索了乙烯基梯形（LL）-乙烯基化合物，即乙烯基（甲基/苯基）硅（氧）[苯基硅氧]（氧）硅（甲基/苯基）乙烯基，与Br-Ar-Br的Heck催化共聚反应。最令人惊讶的是，尽管没有真正的笼结构，但所得的低聚物的发射红移比乙烯基DD乙烯基类似物的发射红移超出30-60纳米。非常规共轭作用的进一步证据包括LL-共-噻吩、联噻吩和噻吩并噻吩与10摩尔％的F TCNQ之间明显的整数电荷转移（ICT），这表明其有作为p型掺杂有机/无机半导体的潜力。
