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Kinetic and thermodynamic study of inter‐ and intramolecular proton transfer in N ′‐acetyl formohydrazide tautomers
Author(s) -
Tavakol Hossein
Publication year - 2010
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.22847
Subject(s) - tautomer , intramolecular force , chemistry , intermolecular force , computational chemistry , molecule , proton , gas phase , kinetic energy , solvent , thermodynamics , stereochemistry , organic chemistry , physics , quantum mechanics
Nine tautomers and eleven possible tautomeric interconversions of N ′‐acetyl formohydrazide have been studied at B3LYP/6‐311++G** level of theory. From these calculations, optimized geometries, molecular parameters, IR frequencies, NMR chemical shifts, and energetic results are obtained. In all tautomers except tautomers 4, E isomer is more stable than Z isomer. Energetic data were used to calculate the energy barriers of tautomeric interconversions and very high energy barriers were obtained for all tautomeric interconversions. Moreover, study of solvent effects on relative stabilities of tautomers and transition states showed that they are similar to those in the gas phase. In addition, intermolecular proton transfer with the assistance of one to three water molecules has been studied and the results showed that activation barriers in water‐assisted tautomerism are in general lower than those in the gas phase. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011