Dicyano-Substituted Acceptor Units in Push-Pull Chromophores with Intramolecular Charge-Transfer

Abstract

Dicyano-substituted acceptor moieties such as dicyano­vinyl, dicyanoimidazole and dicyanopyrazine and their use in charge-transfer chromophores are discussed. Recent contribution to the synthesis, characterization and application of such compounds in nonlinear optics (NLO) and optoelectronics were reviewed and further evaluated. These moieties, in combination with suitable electron donors and π-conjugated systems, were shown to generate highly polarized D-π-A molecules of various shapes and structures. Fine-tuning of NLO properties has been achieved by variation of electronic behavior – the number of appended donors, the length and composition of the π-linker and chromophore planarity.