Synthesis, characterization and photovoltaic properties of platinum-containing poly(aryleneethynylene) polymers with phenanthrenyl-imidazole moiety

A new type of soluble, solution-processable platinum(II) polyyne polymers based on phenanthrenyl-imidazole chromophore and their corresponding diplatinum model complexes were synthesized via the CuI-catalyzed dehydrohalogenation reaction of the platinum(II) chloride precursor and each of the diethynyl ligands. The photophysical (absorption and emission spectra), thermal, electrochemical and photovoltaic properties of the polymers were investigated. Both polymers exhibit strong absorption bands centered at 459–466 nm. The effect of adding thiophene ring along the polymer backbone was evaluated. Bulk heterojunction solar cells fabricated by blending these metallopolymers with methanofullerene were studied, with the power conversion efficiency reaching 0.39%, although the band gap energies of the polymers are not low.