Crystal structure of diaquatris(benzohydrazide-kappa N-2,O)(isophthalato-kappa O)samarium(III) nitrate

The first benzohydrazide complex of a lanthanide is reported. In the title compound, [Sm(C8H4O4) (C7H8N2O)(3)(H2O)(2)]NO3, systematic name diaquatris(benzohydrazide-kappa N-2,O)(isophthalato-kappa O)samarium(III) nitrate, the Sm-III ion is nine-coordinated in a distorted tricapped trigonal-prismatic geometry by three oxygen atoms and three nitrogen atoms from three benzhydrazide (bzz) ligands, one oxygen atom from the isophthalate (itp(2-)) ligand, and two oxygen atoms from coordinated water molecules. The nitrate group is disordered over two sets of sites with occupancy factors of 0.310 (17) and 0.690 (17). In the crystal, adjacent molecules are linked into chains via pairs of O-H center dot center dot center dot O and N -H center dot center dot center dot O hydrogen bonds between the carboxylate acceptor and the coordinated water and amine NH2 donors. Molecules are further stacked by r-rr interactions involving the benzene ring of the itp(2-) ligands, forming double chains that extend in the b-axis direction. These double chains are further linked into a three-dimensional supramolecular network via hydrogen bonds (O- H center dot center dot center dot O, N - H center dot center dot center dot O and C- H center dot center dot center dot O) between the complex molecule and the nitrate groups along with C -H center dot center dot center dot pi and pi-pi interactions involving the benzene rings of the bzz and itp(2-) ligands.