Panchromatic Push–Pull Dyes of Elongated Form from Triphenylamine, Diketopyrrolopyrrole, and Tetracyanobutadiene Modules

Abstract

Several symmetrical and unsymmetrical thiophene-functionalized diketopyrrolopyrrole chromophores bearing a bis(<i>p</i>-methoxyphenyl)-<i>p</i>-phenylamine substituent were synthesized through palladium-catalyzed cross-coupling reactions. Mono-substitution and di-substitution occur using either alkyne or borolane groups, allowing the preparation of mixed systems. The alkyne derivatives could be prepared in high yields, and are versatile building blocks for the [2+2] cy­cloaddition of tetracyanoethylene, leading to 1,1,4,4-tetracyanobuta-1,3-diene derivatives. These interesting push–pull molecules exhibit a rich redox activity, which is understandable in light of the behavior of appropriate reference compounds. These innovative and rationally designed scaffolds are highly colored, exhibiting high absorption coefficients and spanning an absorption range of more than 600 nm of the UV/Vis electromagnetic spectrum.