title: N'-[(E)-1-(2-Hy-droxy-phen-yl)ethyl-idene]pyrazine-2-carbohydrazide.
abstract: The title compound, C13H12N4O2, crystallized with two independent mol-ecules (A and B) in the asymmetric unit. Mol-ecule B is planar to within 0.044 (3) Å for all non-H atoms, while mol-ecule A is slightly twisted, with a dihedral angle of 6.29 (4)° between the mean planes of the pyrazine-2-carbohydrazide and 1-(2-hy-droxy-phen-yl)ethanone moieties (r.m.s. deviations = 0.0348 and 0.0428 Å, respectively). S(5) and S(6) ring motifs are formed in both mol-ecules due to the presence of intra-molecular O-H⋯N and N-H⋯N hydrogen bonds. In the crystal, mol-ecules A and B are linked by a C-H⋯O hydrogen bond. They stack along the a-axis direction, forming columns with π-π inter-actions involving inversion-related pyrazine and benzene rings [centroid-centroid distances = 3.5489 (13)-3.8513 (16) Å].
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan.
authors.forename: Shahid
authors.initials: S
authors.lastname: Hameed
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad, Pakistan ; Medicinal Botanic Centre, PCSIR Laboratories Complex, Peshawar, Pakistan.
authors.forename: Mushtaq
authors.initials: M
authors.lastname: Ahmad
authors.affiliation: University of Sargodha, Department of Physics, Sargodha, Pakistan.
authors.forename: M Nawaz
authors.initials: MN
authors.lastname: Tahir
authors.affiliation: Department of Chemistry, Kohat University of Science and Technology, Kohat, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Israr
authors.affiliation: Department of Chemistry, Kohat University of Science and Technology, Kohat, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Anwar