Photophysical Processes in Polymers. VI. Spectroscopic Properties of 1-Vinylpyrene and Poly(1-Vinylpyrene)

The absorption spectra, corrected fluorescence spectra, and fluorescence quantum yields of 1-vinylpyrene and poly(1-vinylpyrene) are reported. The triplet-triplet absorption spectrum of poly(1-vinylpyrene) is compared to that of pyrene, and the excimer fluorescence of the polymer is studied as a function of temperature. Based upon the temperature dependence of the excimer emission, it is concluded that efficient formation and inefficient emission of nonequilibrium-geometry pyrene excimers takes place in poly(1-vinylpyrene). Radiative and radiationless transition mechanisms are discussed. Values reported for poly(1-vinylpyrene) in fluid solution at room temperature are qFM ≅ 0, qFD = 0.44, qPM ≅ 0, φT = 0.005, kFD = 0.83 × 107sec−1, kGD = 1.0 × 107sec−1, kDM >∼ 1 × 107sec−1, and kTM <∼ 5 × 105sec−1.