TRANSIENT ABSORPTION STUDIES ON 3,6-DIBROMO POLYVINYLCARBAZOLE AND ITS MODEL COMPOUNDS

3,6-Dibromo-N-ethylcarbazole (DBNEC) and its polymeric analogue poly-3 ,6-dibromovinylcarbazole (PDBVCz) were studied by transient absorption spectroscopy. The transient absorption spectrum of the 3,6-dibromo-N- ethylcarbazole radical cation and decay rate constants of radical cati ons of 3,6-dibromo-N-ethylcarbazole and its polymeric analogue are pre sented. In the case of unsubstituted carbazole, the ratio of the yield of radical cation of monomer to polymer is 2.0, whereas in the case o f PDBVCz, under the same experimental conditions, the yield of the rad ical cation is an order of magnitude less in comparison with the monom er model compound DBNEC. This drastic difference in yield has been cor related to the difference in the conformational structure of the polym er as evidenced by nuclear magnetic resonance spectroscopy. (C) 1997 E lsevier Science S.A.