New water-soluble imidazole-containing polymers

Copolymers of 1-vinylimidazole with 1-vinylbenzimidazole, 1-isopropenylimidazole, and 9-vinylcarbazole were synthesized under radical -initiation conditions. The experimental reactivity ratios are in satisfactory agreement with the values calculated in the PM3 approximation, thus indicating the prevalent influence of electronic factors on the activity of the monomers. The potentiometric titration of the copolymers in a hydrochloride form revealed the abnormal stability of a part of protonated imidazole units in the alkaline region, this stability being due to their stabilization by hydrogen bonding. The 9-vinylcarbazole copolymers displayed intense fluorescence whose spectrum resembles that of the low-molecular-mass analog 9-ethylcarbazole.