Crystal structure of bis-{1-phenyl-3-methyl-4-[(quinolin-3-yl)imino-methyl-κ N]-1 H-pyrazol-5-olato-κ O}zinc methanol 2.5-solvate from synchrotron X-ray diffraction

Acta Crystallogr E Crystallogr Commun. 2017 Jul 18;73(Pt 8):1208-1212. doi: 10.1107/S2056989017010441. eCollection 2017 Jul 1.


The title compound, [Zn(C20H15N4O)2]·2.5CH3OH, I, was synthesized via the reaction of zinc acetate with the respective ligand and isolated as a methanol solvate, i.e., as I·2.5CH3OH. The crystal structure is triclinic (space group P-1), with two complex mol-ecules ( A and B ) and five methanol solvent mol-ecules in the asymmetric unit. One of the five methanol solvent mol-ecules is disordered over two sets of sites, with an occupancy ratio of 0.75:0.25. Mol-ecules A and B are conformers and distinguished by the conformations of the bidentate 1-phenyl-3-methyl-4-[(quinolin-3-yl)imino-meth-yl]-1H-pyrazol-5-olate ligands. In both mol-ecules, the zinc cations have distorted tetra-hedral coordination spheres, binding the monoanionic ligands through the pyrazolo-late O and imine N atoms. The two ligands adopt slightly different conformations in terms of the orientation of the terminal phenyl and quinoline substituents with respect to the central pyrazolo-late moiety. The mol-ecular geometries of A and B are supported by intra-molecular C-H⋯O and C-H⋯N hydrogen bonds. In the crystal of I, mol-ecules form dimers both by secondary inter-molecular Zn⋯O [3.140 (2)-3.553 (3) Å] and π-π stacking inter-actions. The dimers are linked by inter-molecular hydrogen bonds through the solvent methanol mol-ecules into a three-dimensional network.

Keywords: Schiff base ligands; crystal structure; pyrazole-quinoline; synchrotron radiation; zinc complex.

Grant support

This work was funded by Ministry of Education and Science of the Russian Federation grant 4.5388.2017/8.9. Ministry of Education and Science of the Russian Federation grant 02.a03.21.0008.