Synthesis of cyclopenta-fused aromatic hydrocarbon radicals

交替含有苯和环戊二烯部分(环戊二烯稠合多芳烃，CP-PAHs)的共轭体系因其特殊的性质而闻名，使它们例如适合用于光电子应用。含有奇数个五元环的CP-PAHs处于中性状态。在本项目中，将通过邻位羧基或邻甲酰基取代的低聚苯基的邻位偶联反应来合成自由基CP-PAHs。生成的中间体应通过氧化或还原方法转移到共轭的CP-PAHs中。环戊二烯上的大体积芳基取代基可以防止自由基中心的副反应。较高的CP-PAHs应该从含有荧烯部分的低聚芳基开始构建。描述了合成含有多达11个环的CP-PAHs的方法。应研究(部分与其他基团合作)目标化合物的芳香族、电子和磁性及其氧化还原活性。实验分析方法将得到量子化学计算的支持。

Conjugated systems, which alternately contain benzene and cyclopentadiene moieties (cyclopenta-fused polyaromatic hydrocarbons, CP-PAHs), are known for their special properties, making them, e.g., suitable for utilization in optoelectronic applications. CP-PAHs containing an odd number of five-membered rings are in their neutral state radicals. In this project radicalic CP-PAHs shall be synthesized by ortho-coupling in ortho-carboxyl- or ortho-formyl-substituted oligophenyls. The resulting intermediates shall be transferred into the conjugated CP-PAHs by oxidative or reductive methods. Side reactions at the radical centers can be prevented by bulky aryl substituents at the cyclopentadienes. Higher CP-PAHs should favorably be constructed starting with oligoaryls containing fluorene moieties. Methods are described for the synthesis of CP-PAHs containing up to eleven rings. The target compounds shall be investigated (partly in cooperation with other groups) with respect to their aromatic, electronic, and magnetic properties and their redox activities. The experimental analytical methods will be supported by quantum chemical calculations.