Polymerization of N‐vinylcarbazole by (3d)‐transition metal oxides

Abstract

The bulk polymerization of N-Vinylcarbazole (NVC) is carried out using some 3 d-metal oxides as catalysts and the following order of reactivity is suggested for the various metal oxides studied :the oxides of copper and cobalt being ineffective. Some kinetic studies are carried out with the NVC/MnOz system. Endorsed by the observed retardation of the rate in the presence of water and thiophene a cationic mechanism is suggested for the polymerization. The incapability of the oxides of Cu and Co to act as good catalysts is tentatively explained by supposing that they act as oxidizing rather than x-complexing polymerization catalysts. Stirring does not show any influence on the rate of polymerization. ZUSAMMENFASSUNG:Die Substanzpolymerisation von N-Vinylcarbazol (NVC) wurde mit 3 d-Metalloxid-Katalysatoren durchgefiihrt, und die folgende Reaktivitatsreihe fur die untersuchten Oxide wurde vorgeschlagen :und COO, wobei die Oxide des Kupfers und Kobalts nicht wirksam sind. Einige kinetische Untersuchungen wurden mit dem System NVC/Mn02 ausgefuhrt. A d Grund der Verzogerung der Polymerisationsgeschwindigkeit bei Gegenwart von Wasser oder Thiophen wurde ein kationischer Mechanismus fur die Polymerisation vorgeschlagen. Die Wirkungslosigkeit der Kupfer-und Kobaltoxide als Katalysatoren wurde vorlaufig mit der Annahme gedeutet, daB sie eher oxydierend wirken als durch x-Komplex-Bindung. Ruhren ubt keinen E i d d auf die Polymerisationsgeschwindigkeit aus.

Conducting composites of poly(N‐vinylcarbazole), polypyrrole, and polyaniline with 13X‐zeolite

“…Initiation of NVC was by interaction between the active Lewis acids sites as well as Bronsted acid sites23 present in 13X zeolite and the π‐electrons of vinyl group in NVC, schematically shown in Scheme (a). Relevantly, a similar pathway was believed to be operative in NVC‐MMT and NVC‐3d‐transition metal polymerization systems, and propagation would follow a carbocationic pathway 2, 12, 24. Termination would be by H transfer or by impurities like adventitious water 25.…”

“…Relevantly, a similar pathway was believed to be operative in NVC-MMT and NVC-3d-transition metal polymerization systems, and propagation would follow a carbocationic pathway. 2,12,24 Termination would be by H transfer or by impurities like adventitious water. 25 The oxidative polymerizations of PY and ANI by Cu (II) oxidant followed the pathway as shown in Scheme 1(b,c), respectively.…”