Tautomeric equilibria for ionized oxamic acid - inhibitor of LDH

Authors

Department of Chemistry, Warsaw University of Life Sciences (SGGW), 02-776 Warszawa, Poland

Abstract

Amide-iminol tautomerism was studied for ionized oxamic acid (OA+•) in the gas phase using the
DFT method with the UB3LYP functional and various basis sets {6-31++G(d,p), 6-311+G(d,p), and augcc-
pVDZ}. Among twenty tautomers-rotamers possible for OA+•, eleven isomers were found to be
thermodynamically stable. Similarly as for the neutral molecule, ionization (OA → OA+• + e) favors the
amidization process (amide ← iminol). Isomerization seems to change solely the conformational
preferences. π-Electron delocalization in the NCO and OCO moieties is close to that for n-π conjugated
fragments.

Keywords


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