Tropone–Containing Conjugated Polymer, Part VInfluence of Fused Benzene Ring upon Photophysical Properties

p–Phenylenevinylene type (P1), p–phenylene type (P2), and p–phenyleneethynylene type (P3) conjugated polymers containing tropone in the main chain were obtained by Heck reaction, Suzuki coupling, and Sonogashira coupling, respectively. The carbonyl stretching vibration peaks in the IR spectra were always detected at the lower wavenumber region compared with that of tropone. P1 and P2 in chloroform had the absorption peak maximum at 515 nm and 400 nm, respectively. The fluorescence from these polymer solutions was almost quenched, in contrast to previously reported P4 bearing benzotropone unit (λem = 566 nm). The acid–doping to P1 did not bring about any spectral change in the UV spectra. From the powder XRD pattern, P1 was found to have the π-stacked structure in the solid state.