Synthesis and characterization of novel (oligo)thienyl-imidazo-phenanthrolines as versatile π-conjugated systems for several optical applications

A series of new heterocyclic chromophores 3-6 were synthesized in moderate to excellent yields by condensation of 5,6-phenantroline-dione with formyl-thiophene derivatives 1-2 in the presence of ammonium acetate in glacial acetic acid. These chromophores possess an (oligo)thienyl π-conjugated system attached to an imidazo-phenanthroline moiety. These derivatives were evaluated concerning their solvatochromic properties, thermal stabilities, and molecular optical nonlinearities.

New thermally stable heterocyclic chromophores 3-6 based on an (oligo)thiophene π-conjugated bridge and an imidazo-phenanthroline moiety were synthesized in moderate to excellent yields by condensation of 5,6-phenanthroline-dione with formyl (oligo)thiophenes 1-2 in the presence of ammonium acetate in glacial acetic acid.