Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, 28040 Madrid, Spain.
J Org Chem. 2009 Sep 18;74(18):7148-56. doi: 10.1021/jo901648d.
Efficient electron delocalization by aromatic homoconjugated 7,7-diphenylnorbornane (DPN) in alternated homoconjugated-conjugated block copolymers and reference compounds is revealed by photophysical and electrochemical measurements. The synthesis of the polymers was achieved by Suzuki polycondensation reaction. Effective electron delocalization by DPN is demonstrated by the significant red shifts observed in the absorption and emission spectra and the variation of the energy band gap of the polymers and monomeric model compounds in comparison to a series of oligophenylenes used as references (p-quaterphenyl, p-terphenyl, and biphenyl). The electron delocalization is also clearly demonstrated by the lower oxidation potential measured for homoconjugated model compound in comparison to p-terphenyl. The results show that the electron delocalization caused by two homoconjugated aryl rings is comparable to the effect produced by one conjugated aryl ring.
通过光物理和电化学测量揭示了芳香同共轭 7,7-二苯基降冰片烷（DPN）在交替同共轭嵌段共聚物和参比化合物中有效电子离域。聚合物的合成通过 Suzuki 缩聚反应实现。与用作参比的一系列寡聚苯（对四苯基、对三联苯和联苯）相比，DPN 的有效电子离域通过吸收和发射光谱中观察到的显著红移以及聚合物和单体模型化合物的能带隙变化得到证明。与对三联苯相比，同共轭模型化合物较低的氧化电位也清楚地表明了电子离域。结果表明，两个同共轭芳环引起的电子离域与一个共轭芳环产生的效果相当。
