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A theoretical study of tautomerism: 2‐ and 4‐oxopyrimidine and some of their derivatives
Author(s) -
Leś A.,
OrtegaBlake I.
Publication year - 1985
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560270506
Subject(s) - tautomer , ab initio , mndo , chemistry , pseudopotential , computational chemistry , basis (linear algebra) , relaxation (psychology) , ab initio quantum chemistry methods , stability (learning theory) , thermodynamics , molecule , atomic physics , physics , mathematics , organic chemistry , computer science , psychology , social psychology , geometry , machine learning
Here we present a detailed study of the theoretical approach to the tautomerization processes considering 2‐ and 4‐oxo‐pyrimidine and several of their derivatives. We look into molecular relaxation, suitability of semiempirical methods, and the effect of basis sets size in pseudopotential ab initio calculations. We found that no semiempirical method is suited for studying the relative stability of the tautomers, even ab initio calculations with minimal basis sets. On the other hand MNDO appears to be very useful for molecular relaxation and can be used, as well as Ab initio calculations, for reasonable estimates of relative tautomerization. We also considered the quality of prediction of other parameters, in particular the ionization potentials. We considered the correlation of experimental and theoretical values as a means to adjust the theoretical results to obtain more reliable predictions.