A new nitrogen rich open chain diazine ligand system: synthesis coordination chemistry and magneto-structural studies

N′-(2-Hydroxy-3-methoxybenzylidene)pyrazine-2-carbohydrazide monohydrate

In the title hydrated Schiff base, the dihedral angle between the aromatic rings is 5.06 (11)° and an intra­molecular O—H⋯N hydrogen bond closes an S(6) ring. In the crystal, O_w—H⋯O and O_w—H⋯N (w = water) hydrogen bonds link the components into centrosymmetric tetra­mers (two Schiff bases and two water mol­ecules). Longer N—H⋯O hydrogen bonds link the tetra­mers into [010] chains.

In the title hydrated Schiff base, C₁₃H₁₂N₄O₃·H₂O, the dihedral angle between the aromatic rings is 5.06 (11)° and an intra­molecular O—H⋯N hydrogen bond closes an S(6) ring. In the crystal, O_w—H⋯O and O_w—H⋯N (w = water) hydrogen bonds link the components into centrosymmetric tetra­mers (two Schiff bases and two water mol­ecules). Longer N—H⋯O hydrogen bonds link the tetra­mers into [010] chains. A weak C—H⋯O hydrogen bond and aromatic π–π stacking between the pyrazine and phenyl rings [centroid–centroid separations = 3.604 (2) and 3.715 (2) Å] are also observed.

N′-[1-(Pyrazin-2-yl)ethylidene]pyrazine-2-carbohydrazide

The title compoud, C11H10N6O, was synthesized by the condensation reaction of pyrazine-2-carbohydrazide with 2-acetylpyrazine in ethanol. The dihedral angle between the pyrazine rings is 4.7 (3)°. In the crystal, aromatic π–π stacking [centroid–centroid separations = 3.606 (5) and 3.671 (5) Å] connect the molecules into stacks propagating in the [010] direction. A weak C—H...N interaction is also observed. The crystal studied was refined as a two-component twin.