N-Vinyl imidazoles

In this case, a moderately water-soluble amphiphilic N-vinylcaprolaclam (NVC1) played the role of a fl-unit, and a well-water-compatible N-vinyl-imidazole (NVIAz) served as a P-unil. The polymerization was carried out in a medium of 10% aqueous dimethylsulfoxide (DMSO). The addition of DMSO to the reaction solvent was necessary because of insufficient NVC1 solubility in pure water. It was also shown that in this solvent mixture, the NVCl-homopolymers and NVCl/NVIAz-copolymers retained their LCST-behaviour [26,28]. Hence, the DMSO in the reaction solvent did not significantly suppress the hydrophobic interactions of the NVC1 units. The polymerization was initiated by the redox system (N,N,N, N -tetramethylethylenediamine (TMEDA) + ammonium persulphate (APS)) and was carried out at 65 °C (1st step). This condition was very important, since admittedly the temperature was higher than the phase separation threshold of the reaction bulk when the polymeric products were formed that is, under these thermal conditions, hydrophobically-induced folding as the NVCl-blocks appear was ensured. After completion of the reaction, the... 

Experimentally, the described synthetic strategy was first realized by Lozinsky et al. [80,81], who studied the redox-initiated free-radical copolymerization of thermosensitive N-vinylcaprolac lam with hydrophilic N-vinyl-imidazole at different temperatures. These and other experimental studies [82 - 84] showed the universality of this approach of obtaining copolymers capable of forming nanostructures with a core-shell morphology. 

Poly(N-vinyl-imidazole) (PVI) and Poly(4(5)-vinyl-imidazole) (P4VI). . 62... 

Poly N(vinyl-imidazole) can be obtained by radical polymerization of the corresponding monomer 36>, which is a commercial product. 

Cross-linked poly(N-vinyl-imidazole) was obtained by reaction of poly(N-vinyl-imidazole) with 1,4 dibromobutane37>. 

Poly(N-vinyl-imidazole) is an essentially monofunctional polybase, as shown by the sharpness of the jump in the titration curve 89). From conductance measurements, it was found that the data fitted the Henderson-Hasselbach expression with a term for the ionic strength ... 

In the case of Ag+, only two imidazolyl groups participate in complex formation, and the overall stability constant is log p2 = 8.00, about one order of magnitude larger than the overall formation constant of the Ag/imidazole complex (log p2 = 6.84). Complexes of Cu2 + with poly 4(5)-vinyl-imidazole, poly(N-vinyl-imidazole), and... 

Fe(lI,in)-protoporphyrin-IX-dfester (7 c, d) with poly(N-vinyl)-imidazole) polystyrene (in mixture with l-(2-phenyl-ethylimidazde) . ... 

M = St, MM A. N-vinyl pyrrolidone, N-vinyl imidazole, N-methyl methacrylamide NCA = y-benzyl glutamate or N -benzyloxycarbonyl lysine N-corboxy onhydrides... 

Leonhardt and Mosbach prepared metal-complexing imprinted polymers by polymerising Co " complexes of N-vinyl imidazole and A-protected amino acids [14]. After work-up of the polymer and removal of the amino acid templates, the catalytic activities of the resulting imprinted metal-complexing polymers were evaluated by following the hydrolysis of the p-nitrophenyl esters of various amino acids. Assessment of the rate of hydrolysis revealed a clear preference for the substrates used as the templates. The polymers could be used several times without any deterioration of the catalytic activities and true turnover was observed. 

Glucose oxidase (GOX) was electrically wired to glassy carbon electrodes by redox hydrogels based on poly (N-vinyl imidazole)... 

Scheme 3 Reactions of diazomethines lla-cand N-vinyl-imidazole(15) withTCNE, 1.

Activity studies of glucose immobilized onto poly(N-vinyl imidazole) and metal ion chelated poly (N-vinyl imidazole) hydrogels. J. Mol. Catalysis B Enzym., 21, 273. 

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