Synthesis and tuning of optical properties of conjugated polymers involving benzo[h]quinoline-based neutral pentacoordinate organosilicon complexes in the main chain

We present the synthesis and optical properties of a series of alternating polymers containing pentacoordinate silicon complexes in the main chain. By employing the benzo[h]quinoline ligand, the pentacoordinate silicon complexes were obtained. The polymers were prepared via the Sonogashira-Hagihara coupling reaction. From the series of measurements for optical properties of the synthesized polymers, new absorption bands and bathochromic shifts in emission spectra were observed. These data suggest that intramolecular charge transfer could occur after the excitation because of the elongation of π-conjugation via the polymer main chains. The modulation of the optical properties of the conjugated polymers involving the pentacoordinate silicon was accomplished.