caa a22 4500 605510709 CHVBK 20210128100647.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00894-015-2574-8 doi (NATIONALLICENCE)springer-10.1007/s00894-015-2574-8 Direct and solvent-assisted keto-enol tautomerism and hydrogen-bonding interactions in 4-( m -chlorobenzylamino)-3-phenyl-4,5-dihydro-1 H -1,2,4-triazol-5-one: a quantum-chemical study [Elektronische Daten] [N. Arslan, Namık Özdemir] The tautomeric equilibrium of the title triazole compound was computationally analyzed at the B3LYP/6-311++G(d,p) and MP2/6-311++G(d,p) levels of theory. The solvent effect was considered for three solvents (chloroform, methanol, and water). Two distinct mechanisms were applied: a direct intramolecular transfer using the polarizable continuum model (PCM) and a solvent-assisted mechanism. The calculations indicated that the keto form is more stable in all cases. It was found that the barrier heights for the tautomerization reaction are very high, indicating a relatively disfavored process. Although the barrier heights for solvent-assisted reactions are significantly lower than those for the unassisted tautomerization reaction, implying the importance of the superior catalytic effect of the solvents, monosolvation was not found to be sufficient for the reaction to occur. Finally, the two intermolecular hydrogen-bonding interactions in the crystal structure were investigated in the gas phase; according to the calculated energies and structural parameters, the order of stability is N3-H3···O1 > N1-H1···O1. Springer-Verlag Berlin Heidelberg, 2015 1,2,4-Triazole nationallicence DFT nationallicence MP2 nationallicence Keto-enol tautomerism nationallicence Solvent effect nationallicence Hydrogen bonding nationallicence Arslan N. Department of Computer Education and Instructional Technology, Faculty of Education, Giresun University, 28100, Giresun, Turkey aut Özdemir Namık Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139, Samsun, Turkey aut Journal of Molecular Modeling Springer Berlin Heidelberg 21/1(2015-01-01), 1-10 1610-2940 21:1<1 2015 21 894 https://doi.org/10.1007/s00894-015-2574-8 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00894-015-2574-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Arslan N. Department of Computer Education and Instructional Technology, Faculty of Education, Giresun University, 28100, Giresun, Turkey aut NATIONALLICENCE 700 1- Özdemir Namık Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayıs University, 55139, Samsun, Turkey aut NATIONALLICENCE 773 0- Journal of Molecular Modeling Springer Berlin Heidelberg 21/1(2015-01-01), 1-10 1610-2940 21:1<1 2015 21 894