부산대학교 도서관

Quantum chemical caculations of the most stable conformers of methylamine-pyridoxal-5-phosphate Schiff base three tautomeric (enol, keto, and zwitterionic) structures and their monohydrates and dihydrates have been carried out at the B3LYP/6-31+G**, M062X/6-31+G**, and BVP86/TZVP levels of theory. The optimized structures, harmonic force fields, and vibrational frequencies of tautomers have been obtained. The influence of macrohydration on the conformational composition of tautomers have been studied using the polarized continuum model. Vertical ionization potentials of the most stable monohydrates and dihydrates of methylamine-pyridoxal-5'-phosphate tautomers have been calculated. The influence of macrohydration and microhydration on the structure, spectra, and vertical ionization energies of the monohydrates and dihydrates of methylamine-pyridoxal-5-phosphate tautomers have been discussed.