Copolymerization of vinylferrocene and N-vinylcarbazole. Conductivity studies of the trinitrofluorenone and mixed-valence [Fe(II), Fe(III)] complexes of these copolymers

Abstract

Vinylferrocene (M1) has been copolymerized with N-vinylcarbazole (M2) using azobisisobutyronitrile as the initiator. In benzene at 70°C, the reactivity ratios r1 = 0.47 and r2 = 0.20 were obtained. Using an e value of −1.34 for N-vinylcarbazole, the calculated value e for vinylferrocene is about −2.8, in general agreement with the large negative e values vinylferrocene exhibits with other monomers which are electron rich. These copolymers were treated with trinitrofluororenone to give copolymers with carbazole–trinitrofluorenone charge–transfer complex sites (type B). The copolymers were oxidized with dichlorodicyanoquinone to give a series of copolymers with both ferrocenium and ferrocene sites in them (type C). In addition, type C copolymers were further treated with trinitrofluorenone to give a class of polymers having ferrocene, ferrocenium and carbazole–trinitrofluorenone charge–transfer sites (type D). Introducing ferrocene and ferrocenium sites into the poly(vinylcarbazole–trinitrofluorenone) polymers resulted in an increase in their conductivity, but the polymers were no longer photoconducting.