title: 4-([(1E)-(2-Hydroxyphenyl)methylidene]amino)-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one.
abstract: In the title compound, C18H17N3O2, a strong intramolecular O-H...N hydrogen bond [N...O 2.607 (3), O-H 0.97 (3) and H...N 1.71 (3) A, and O-H...N 153 (2) degrees ] was observed, which leads to a unique phenol-imine tautomerism in the solid state. The C=N imine bond distance and the C-N-C bond angle [1.287 (2) A and 121.7 (1) degrees, respectively] indicate the existence of this phenol-imine tautomer. In solution, the phenol-imine tautomer of the title free Schiff base ligand is dominant in both polar and non-polar solvents, as supported by 1H NMR and UV-visible spectroscopic data.
authors.affiliation: Hacettepe University, Department of Physics, 06532 Beytepe, Ankara, Turkey. merzifon@hacettepe.edu.tr
authors.forename: T
authors.initials: T
authors.lastname: Hökelek
authors.forename: M
authors.initials: M
authors.lastname: Işiklan
authors.forename: Z
authors.initials: Z
authors.lastname: Kiliç