Synthesis and second-order nonlinear optical properties of new chromophores containing benzimidazole, thiophene, and pyrrole heterocycles

New efficient and thermally stable NLO chromophores 4 and 5 based on a thienylpyrrolyl donor π-conjugated bridge and a benzimidazolyl acceptor moieties were developed by a one-step Na2S2O4 reduction of substituted o-nitroanilines in the presence of formyl-thienylpyrroles.