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The title compound, C13H12N4O2, crystallized with two independent molecules (A and B) in the asymmetric unit. Molecule B is planar to within 0.044 (3) Å for all non-H atoms, while molecule A is slightly twisted, with a dihedral angle of 6.29 (4)° between the mean planes of the pyrazine-2-carbohydrazide and 1-(2-hydroxyphenyl)ethanone moieties (r.m.s. deviations = 0.0348 and 0.0428 Å, respectively). S(5) and S(6) ring motifs are formed in both molecules due to the presence of intramolecular O—H
N and N—HN hydrogen bonds. In the crystal, molecules A and B are linked by a C—HO hydrogen bond. They stack along the a-axis direction, forming columns with π–π interactions involving inversion-related pyrazine and benzene rings [centroid–centroid distances = 3.5489 (13)–3.8513 (16) Å].
N and N—HN hydrogen bonds. In the crystal, molecules A and B are linked by a C—HO hydrogen bond. They stack along the a-axis direction, forming columns with π–π interactions involving inversion-related pyrazine and benzene rings [centroid–centroid distances = 3.5489 (13)–3.8513 (16) Å].organic compoundsOpen access
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In the title compound, C12H9BrN4O, the dihedral angle between the aromatic rings is 12.16 (12)°. An intramolecular N—HN hydrogen bond closes an S(5) ring. In the crystal, C—HO hydrogen bonds link the molecules into C(6) chains propagating in [010]. Very weak aromatic π–π stacking [centroid–centroid separations = 3.9189 (15) and 3.9357 (15) Å] is also observed.
N hydrogen bond closes an S(5) ring. In the crystal, C—HO hydrogen bonds link the molecules into C(6) chains propagating in [010]. Very weak aromatic π–π stacking [centroid–centroid separations = 3.9189 (15) and 3.9357 (15) Å] is also observed.
