Vinylimidazole-vinylphenol copolymers

Copolymer of 4(5)-vinylimidazole and p-vinylphenol Poly-4(5)-vinylimidazole Imidazole... 

IM-OH cooperation. It is interesting that the appearance of a cooperation between imidazole and hydroxyl moieties in the synthetic polymer is found, as is observed in a-chymotrypsin-catalyzed hydrolysis. The cooperation is ascertained in the hydrolyses catalyzed by copolymers of 4 5)-vinylimidazole with vinyl alcohol, poly(IM-al) (VI), and with p-vinylphenol, poly(IM-ph) (VII) (77, 78). 

We have noted previously that the catalytic effect of the hydrolytic enzyme chymotrypsin depends critically on the interaction of a hydroxyl and an imidazole group placed in juxtaposition in the enzyme molecule. It was, therefore, particularly tempting to see if an analogous interaction could enhance the catalytic efficiency of PVI, by using copolymers of 4(5)-vinylimidazole with p-vinylphenol (VI/VP) or with vinyl alcohol (VI/VA)... 

More interesting are the results obtained with copolymers of vinylimidazole and vinylphenol 31. It is a superior catalyst at high pH values toward neutral (PNPA 3), anionic (NABA 6, NABS 5), and cationic (ANTI 32) substrates, compared with any of its monomeric or polymeric analogs. For instance, the solvolytic rate of ANTI 32 with this copolymer was ca. 63 times greater than that of imidazole at pH 9.1. 

Copolymers of 4(5)-vinylimidazole with vinylalcohol or p-vinylphenol (Figure 3) were used to show the cooperative interaction of imidazole and hydroxyl groups in the catalytic process of ester hydrolysis [8, 9]. 

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