Pendent polymers of 1-methyl-2-oxo-4,5-dicyanoimidazole and their electrochemical properties

Abstract

The electron accepting 1-methyl-4,5-dicyanoimidazole group was attached to vinyl polymers, via an alkoxy link, by nucleophilic aromatic substitution (NAS) of 1-methyl-2-fluoro-4,5-dicyanoimidazole (1) with poly(vinyl alcohol), or conventional polymerizations of vinyl monomers containing 1-methyl-2-oxo-4,5-dicyanoimidazole. The cyclic voltammetry (CV) studies show that monomeric and oligomeric model compounds are electrochemically quasi-reversible and the degree of reversibility decreases as dicyanoimidazoles become more proximate within a molecule. On the other hand, the polymers show much less reversible reduction waves at Ϫ2.6ϳϪ2.7 V vs Ag/Ag ϩ , suggesting that there are chemical reactions among the pendent groups reduced at relatively high potential.

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

“…Fig. 14 shows a selection of Rasmussen’s 4,5-dicyanoimidazole derivatives, such as vinazene 73 [ 29 , 81 ], push–pull amines and betaines 74 – 78 [ 82 – 87 ], alkoxy derivatives 79 , 80 [ 88 ], biimidazoles 81 [ 89 – 92 ], and triimidazoles 82 [ 93 – 94 ], as well as fullerenes [ 95 ] and polymers [ 96 – 99 ].…”

“…Variously 4,5-dicyanoimidazole-functionalized polymers were mainly investigated by Rasmussen et al [ 29 , 81 , 86 – 88 96 – 99 ]. However, these systems were not intended as nonlinear optical polymers.…”