Three 3-Amino-1, 2, 4-Triazole-Based Magnetic Complexes Incorporated with Different Carboxylate-Containing Coligands: Synthesis, Structures, and Magnetic Properties

Crystal structure of trans-di-aqua-bis-(nicotinamide-κN (1))bis-(4-nitro-benzoato-κO)manganese(II)

In the title centrosymmetric Mn^II complex, the Mn^II atom is coordinated by two 4-nitro­benzoate (NB) anions, two nicotinamide (NA) ligands and two water mol­ecules; the NB and NA ligands act as monodentate ligands. The resulting MnN₂O₄ coordination polyhedron is a distorted octa­hedron.

The asymmetric unit of the title compound, [Mn(C₇H₄NO₄)₂(C₆H₆N₂O)₂(H₂O)₂], contains one Mn^II atom, one 4-nitro­benzoate (NB) anion, one nicotinamide (NA) ligand and one water mol­ecule; NA and NB each act as a monodentate ligand. The Mn^II atom, lying on an inversion centre, is coordinated by four O atoms and two pyridine N atoms in a distorted octa­hedral geometry. The water mol­ecules are hydrogen bonded to the carboxyl­ate O atoms. The dihedral angle between the carboxyl­ate group and the adjacent benzene ring is 24.4 (3)°, while the benzene and pyridine rings are oriented at a dihedral angle of 86.63 (11)°. In the crystal, O—H⋯O and N—H⋯O hydrogen bonds link the mol­ecules, forming a layer parallel to the ab plane. The layers are further linked via weak C—H⋯O hydrogen bonds, a π–π stacking inter­action [centroid–centroid distance = 3.868 (2) Å] and a weak C—H⋯π inter­action, resulting in a three-dimensional network.