Kinetic and Thermodynamic Study of Inter- and Intramolecular Proton
Transfer in N0-Acetyl Formohydrazide Tautomers
International Journal of Quantum Chemistry, Vol 111, 3717–3724 (2011)
Nine tautomers and eleven possible tautomeric interconversions of N0- acetyl formohydrazide have been studied at B3LYP/6-311þþG** 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.