FLUORESCENCE OF PERYLENE-CONTAINING AND NAPHTHALENE-CONTAINING POLYIMIDES - EVIDENCE OF MOLECULAR AGGREGATION AND CHAIN COILING IN CHLOROFORM SOLUTION

Fluorescence of several new polyimides in which neighboring imides are linked by a N-N bond was examined in chloroform solutions. For the naphthalene-containing polyimide 1, analysis of the emission, excitation, and absorption spectra at different concentrations showed the existence of a ground-state intermolecular charge transfer (CT) complex due to chain association and aggregation. For the perylene-containing polyimides 3-6, the fluorescence was characterized by a low energy band superimposed on the normal perylene-diimide bands. This was interpreted as arising from a CT interaction between electron donor-acceptor pairs on the polymers backbone of the same chain, revealing certain degrees of chain coiling of these polymers in solution. (C) 1995 John Wiley & Sons, Inc.