The Molecular Foundry, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720, USA.
Chem Asian J. 2012 Nov;7(11):2615-20. doi: 10.1002/asia.201200631. Epub 2012 Sep 3.
Ladder-type oligophenylenes (LOPP) with bridging heteroatoms are interesting systems as they offer novel electronic and photophysical properties on account of the rigid structural features, more efficient electron delocalization on the coplanar aromatic framework, and strong intermolecular interactions. LOPPs incorporating multiple phosphorous centers combine the excellent electronic properties of phospholes and rigidified conjugated framework of LOPPs, thus positioning themselves as an attractive class of organic semiconductors. To date, there still lacks an effective synthetic methodology towards LOPPs with multiple phosphorous bridges. Herein, we describe the synthesis and properties of a new class of bisphosphole-bridged ladder oligo(p-phenylene)s and the related phosphoxides. The synthesis of phospholes was achieved by a four-fold free-radical phosphanylation reaction of a tetrabromo p-terphenylene or biphenyl-thiophene. Sequential trapping of four highly reactive aryl radicals occurred effectively to give the desired phosphorous-containing ladder compound. The oxides of the phospholes are shown to be strong fluorophores that can be used as potential n-type building blocks for organic semiconducting materials.
梯型寡聚亚苯基（LOPP）具有桥连杂原子，是一类有趣的体系，由于其刚性的结构特征、共面芳香骨架上更有效的电子离域以及强的分子间相互作用，它们具有新颖的电子和光物理性质。含多个磷中心的 LOPP 结合了磷叶立德的优异电子性质和 LOPP 的刚性共轭骨架，因此成为一类有吸引力的有机半导体。迄今为止，对于具有多个磷桥的 LOPP，仍然缺乏有效的合成方法。在此，我们描述了一类新型双磷桥联梯型寡聚对亚苯基和相关的氧化膦的合成和性质。磷叶立德的合成是通过四溴对三联苯或联苯-噻吩的四自由基膦化反应来实现的。四个高反应性芳基自由基的连续捕获有效地得到了所需的含磷梯型化合物。磷叶立德的氧化物是强荧光团，可以用作潜在的 n 型有机半导体材料的构建块。
