Preparation and properties of π-conjugated poly(benzimidazole-4,7-diyl)s

摘要: Preparation, optical properties, and electrochemical redox behavior of poly(benzimidazole-4,7-diyl)s are reported. Dehalogenation polycondensation 4,7-dibromobenzimidazole its derivatives (2-heptyl 2-phenyl derivatives) with zerovalent nickel complexes gives the corresponding polymers in 72-100% yield. Poly(benzimidazole-4,7-diyl) heptyl derivative have molecular weights 1.3 × 10 4 3.8 , respectively, as determined by light scattering measurements. In non-acidic solvents give rise to one absorption peak at about 300 nm, which is assigned a π-π * transition occurring benzimidazole monomeric unit, another longer wavelength, considered originate from π-conjugated main chain. The peak, well photoluminescence polymers, shifted acidic media due protonation. electrochemically active regarding reduction (or n-doping) show electrochromism.