Symmetrical and unsymmetrical donor-acceptor (D–A) based chromophores were designed and synthesized by the Pd–catalyzed Sonogashira cross–coupling reaction of 1,1′-diiodoferrocene with (4-N,N-dimethylaminophenyl)ethyne followed by [2+2] cycloaddition-retroelectrocyclization reaction with tetracyanoethylene (TCNE) or 7,7,8,8-tetracyanoquinodimethane (TCNQ). Ferrocene was used as a central donor unit and 4-(N,N-dimethylamino)phenyl group as the end-capping donor. Herein, we report the cycloaddition-retrocyclization reaction of TCNE/TCNQ groups on the disubstituted ferrocene containing more than one triple bond to get disubstituted tetracyanobutadiene (TCBD) and cyclohexa-2,5-diene-1,4-diylidene-expanded TCBD products. The effect of the conjugation length and different π–acceptor linkers were investigated by photophysical, redox and computational studies. The redox study reveals multiple oxidation waves corresponding to donor moieties (ferrocene and 4-(N,N-dimethylamino)phenyl group) and reduction waves corresponding to acceptor units (TCBD / cyclohexa-2,5- diene-1,4-diylidene-expanded TCBD). The thermogravimetric analysis data shows that the compounds exhibit high thermal stability. The computational studies reveal HOMO-LUMO gaps consistent with the experimentally obtained data.

通过 1,1'-二碘二茂铁与 (4- N,N-二甲基氨基苯基)乙炔的 Pd 催化 Sonogashira 交叉偶联反应设计和合成基于对称和不对称供体-受体 (D–A) 的发色团，然后 [2+ 2]与四氰乙烯(TCNE)或7,7,8,8-四氰基醌二甲烷(TCNQ)的环加成-逆电环化反应。使用二茂铁作为中心供体单元，4-( N,N-二甲基氨基)苯基作为封端供体。在此，我们报道了TCNE/TCNQ基团在含有一个以上三键的二取代二茂铁上发生环加成-再环化反应，得到二取代四氰基丁二烯(TCBD)和环己-2,5-二烯-1,4-二亚基扩展的TCBD产物。通过光物理、氧化还原和计算研究研究了缀合长度和不同 π 受体连接体的影响。氧化还原研究揭示了对应于供体部分（二茂铁和 4-( N,N-二甲基氨基）苯基）的多个氧化波和对应于受体单元（TCBD / 环己-2,5-二烯-1,4-二亚基-）的还原波扩展了 TCBD）。热重分析数据表明该化合物表现出较高的热稳定性。计算研究揭示了 HOMO-LUMO 间隙与实验获得的数据一致。