Z. Slanina et al., COMPLEXES OF 2-AMINOPYRIMIDINE, 2-HYDROXYPYRIMIDINE AND THEIR TAUTOMERS WITH WATER - RELATIVE THERMODYNAMIC STABILITIES, Thermochimica acta, 228, 1993, pp. 1-7
Relative stabilities in two pairs of complexes of tautomers of substit
uted pyrimidine (2-aminopyrimidine and 2-iminopyrimidine; 2-hydroxypyr
imidine and 2-oxypyrimidine) with water have been computed. Descriptio
n of the isomers is based on ab initio SCF calculation, with energetic
s corrected by the second-order perturbation treatment. The relative s
tabilities are evaluated in terms of partition functions constructed f
rom the calculated dimeric parameters. Complexes of 2-hydroxypyrimidin
e and 2-oxypyrimidine with water were found to coexist at higher tempe
ratures. However, the overall heat capacity can be enhanced by about 3
%, at most, by the isomeric interplay. The relation to non-equilibrium
situations is discussed.