PROPERTIES OF THE COMPLEX SALT OBTAINED BY DOPING THE POLY(N-VINYLCARBAZOLE) WITH BROMINE

Poly(N-vinylcarbazole) (PVK) powder has been doped by bromine at room temperature and also at 370, 420 and 470 K for 24-72 h. It is shown, b y electron spin resonance (e.s.r.), optical absorption, X-ray photoele ctron spectroscopy (XPS), that a charge transfer complex (CT complex) is formed between PV-K and Br. However, some bromine is found to react with PVK, even after doping at room temperature, by addition or subst itution, since not only bromine anion, which evidences the presence of the charge transfer complex, but also neutral bromine, has been detec ted by CPS. After heating, our results show that PVK is transformed in to a new, more insoluble polymer. This polymer is amorphous, while som e traces of carbazole and NH4Br are present in the powders. The increa se of the conductivity is probably related to the formation of some pi bonds in the new amorphous polymer. (C) 1998 Elsevier Science Ltd. Al l rights reserved.