Bis(μ-4-methyl­benzoato-κ2 O:O′)bis­aqua­(4-methyl­benzoato-κ2 OO′)zinc(II)–bis­(μ-4-methyl­benzoato-κ2 O:O′)bis­(4-methyl­benzoato-κO)(nicotinamide-κN)zinc(II)–water (1/1/2)

摘要

The crystal structure of the title compound, [Zn2(C8H7O2)4(H2O)2]·[Zn2(C8H7O2)4(C6H6N2O)2]·2H₂O, consists of two kinds of dinuclear Zn^II complexes (complex A and complex B) and uncoordinated water mol­ecules. In complex A, [Zn₂(C₈H₇O₂)₄(H₂O)₂], each Zn cation is chelated by a 4-methyl­benzoate (PMB) anion and coordinated by a water mol­ecule, and is further bridged by two PMB anions in a trigonal-bipyramidal geometry. In complex B, [Zn₂(C₈H₇O₂)₄(C₆H₆N₂O)₂], each Zn^II cation is coordinated by a monodentate PMB anion and one nicotinamide (NA) ligand, and is further bridged by two PMB anions in a tetra­hedral geometry. Weak intra-mol­ecular π–π stacking between adjacent benzene rings is observed in complex B, the centroid–centroid distance being 3.710 (2) Å. Extensive O—H⋯O and N—H⋯O hydrogen bonding and weak C—H⋯O hydrogen bonding is present in the crystal structure. The crystal studied was a racemic twin; the minor twin component refined to 38%.