TY - JOUR A1 - Hennecke, Manfred A1 - Damerau, Thomas A1 - Müllen, K. T1 - Fluorescence depolarization in poly(p-phenylphenylenevinylene) and related oligomers JF - Macromolecules N2 - The photophysical behavior of poly(p-phenylphenylenevinylene) (PPPV) and several oligomeric model compounds in isotropic and anisotropic samples is investigated by means of polarized fluorescence spectroscopy. As long as excitation energy transfer and mutual alignment are considered, the behavior of PPPV can be modeled by a chain consisting of a distribution of independent oligomeric segments. The results of fluorescence polarization, e.g., the nonzero value of r in isotropic PPPV, cast doubt on the application of the semiconductor band model but favor an interpretation of spectroscopic properties in terms of molecular transitions. The orientation coefficients of the oligomers and of PPPV in stretched polyethylene are determined. The change of fluorescence spectra of oriented PPPV in stretched polyethylene demonstrates directly that conformational changes of the macromolecule influence the pathway of energy transfer. PY - 1993 DO - https://doi.org/10.1021/ma00065a026 SN - 0024-9297 SN - 1520-5835 VL - 26 IS - 13 SP - 3411 EP - 3418 PB - American Chemical Society CY - Washington, DC AN - OPUS4-23165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -