Branched charge-transfer chromophores featuring a 4,5-dicyanoimidazole unit

Six branched and stable push–pull chromophores featuring 4,5-dicyanoimidazole as an acceptor moiety, an N,N-dimethylamino group as a donor and various π-conjugated linkers are reported. Systematic extension of the π-linker revealed that the optical and electrochemical properties of A–π–D chromophores are mainly affected by the nature of the π-conjugated backbone (length and planarity) as well as by the number of appended donors.