Biopolym. Cell. 1992; 8(1):51-56.
http://dx.doi.org/10.7124/bc.00030F
Structure and Function of Biopolymers
Isocytosine tautomerism in solution
1Pivovarov V. B., 1Sheina G. G.
  1. B. I. Verkin Institute for Low Temperature Physics and Engineering, NAS of Ukraine
    47, Prospekt Lenina, Kharkiv, Ukraine, 61103

Abstract

Studies on temperature changes in vibrational spcctra of aqueous solutions of isocytosine (i-Cyt) and its model compounds in the range from 23 °C to 98 °C are aimed at revealing rare tautomeric forms of i-Cyt in solutions and at clearing up physicochemical conditions of their existence. IR-spectra of methanol solutions of the above compounds are obtained. Spectral analysis and comparison between results obtained and literature data allow to conclude that tautomeric equilibrium of i-Cyt is of keto-amine – keto-imine type. The supposition of the energetic advantage of the existence of the tautomer with lesser dipole moment due to the lesser polar environment gives and argument for the increase of the rare imine form concentration at the increase of the solution temperature
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