Electroactive and Photoactive Rod-Coil Copolymers: Design, Synthesis, and Supramolecular Regulation of Photophysical Properties

Autor: John A. Osaheni, Samson A. Jenekhe
Rok vydání: 1995
Předmět:
Zdroj: Journal of the American Chemical Society. 117:7389-7398
ISSN: 1520-5126
0002-7863
DOI: 10.1021/ja00133a012
Popis: Two series of electroactive and photoactive rod-coil copolymers have been designed, synthesized, and investigated to explore a new structural motif for organizing molecular and macromolecular materials at the supramolecular structure level for enhanced functional and solid state photophysical properties. The rod-coil copolymers consisting of electroactive and photoactive rodlike conjugated segments and inactive coillike segments, exemplified by poly(1,4-phenylene benzobi sthiazole-co-decamethylene benzobisthiazole) and poly( 1 ,4-phenylenebisvinylene benzobisthiazole-co-decamethylene benzobisthiazole), have semi-flexible (semi-rigid) chains whose flexibility (rigidity), folding, intermolecular interactions, and packing, and hence the solid state supramolecular structure and photophysical properties of the materials, are regulated by copolymer composition. The molecular structure, chain sequence lengths, and copolymer composition were determined by NMR (1H, 13C), FTIR, and UV-Visible spectra. The sequence length distribution of the conjugated rodlike segments predicted from the copolymerization statistics was in good agreement with the 1H NMR results. It is shown that nanocomposites are formed at rod molar fractions of less than 0.5 which also marks a dramatic change in the photophysical properties of the copolymers. The photoluminescence quantum yield varied with copolymer composition, reaching over 6- and 7-fold enhancements compared to the "bulk" pure conjugated polymers. jg
Databáze: OpenAIRE