The mixed Co(II)/Ni(II) complex, [Co2.67Ni1.33L4(CH3COO)2][BPh4]2·0.75H2O where HL = 4-(salicylaldimine)antipyrine, was isolated as an orange solid from the reaction of 4-(salicylaldimine)antipyrine, with mixed cobalt(II) acetate and nickel(II) acetate in ethanol. The complex was characterized by Frustrated Total Internal Reflection (FTIR), UltraViolet Visible spectroscopy (UV-Vis), X-ray single crystal diffraction, and by elemental analysis. The complex is composed of two symmetry independent cationic units, A and B. The two units are essentially isostructural; nevertheless, small differences exist between them. The units contain four metal atoms, arranged at the corners of a distorted cubane-like core alternately with phenoxy oxygen of the Schiff base. The overall eight corners occupied by metal ions in the asymmetric unit are shared between cobalt and nickel in a 5.33:2.67 ratio. Each metal divalent cation binds three coordinated sites from the corresponding tridentate Schiff base ligand, the fourth one is bound by the acetate oxygen, the fifth and the sixth donor sites come from the phenolate oxygens of other Schiff base ligands. Intermolecular hydrogen bonds join the complexes to the water molecules present in the crystal packing. The magnetic characterization was carried out for this new complex and for its isostructural counterpart containing only cobalt ions. The magnetic measurements for the cobalt(II)/nickel(II) mixed compound indicate either antiferromagnetic interactions among the two cubanes or an anisotropic contribution, whereas a ferromagnetic interaction is observed within the cubane, for both the complexes, as expected by geometrical considerations. A comparison between the magnetic properties of the pure cobalt(II) derivative and similar systems discussed in literature, is presented.

In the title two-dimensional coordination polymer, {[Cu2(C9H3O6)(OH)(C10H8N2)2]·3H2O}n, each of the two independent CuII atoms is coordinated by a bridging OH group, two O atoms from two benzene-1,3,5-tri­carboxyl­ate (L) ligands and two N atoms from a 2,2- bi­pyridine (bipy) ligand in a distorted square-pyramidal geometry. Each L ligand coordinates four CuII atoms, thus forming a polymeric layer parallel to the bc plane with bipy molecules protruding up and down. The lattice water mol­ecules involved in O—H⋯· O hydrogen bonding are situated in the inner part of each layer. The crystal packing is consolidated by π–π inter­actions between the aromatic rings of bipy ligands from neigbouring layers [inter­centroid distance = 3.762 (3) Å].

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<div class="WordSection1"><p>The new title binuclear Ni (II) compound <strong> </strong>(<strong>1</strong>) and the novel pentanuclear Ni (II) cluster {[   } <strong>(2) </strong>are formed from the reaction of an asymmetric Schiff base ligand <strong>L </strong>(L = 4-(salicylaldiminato)antipyrine) with Ni .4  in the former or Ni(ClO₄)₂.6H₂O in presence of malonate in the later.  Complex (<strong>1</strong>) consists of ( ]⁺cation) and one uncoordinated tetraphenylborate anion.  The cation adopts a distorted octahedral arrangement around each metal center.  In the binuclear unit both Ni(II) ions are linked through two phenolate (µ₂-O) oxygen atoms of L, and two oxygen atoms of a  bridging carboxylate group. Each Ni (II) coordinates to four oxygen atoms at the basal plane, two oxygen atoms from two bridging phenolate groups, one from pyrazolone ring and the last of an aqua molecule, and at the axial positions to a bridging carboxylate-O atom and an azomethine nitrogen atom.  In the pentanuclear cluster (<strong>2</strong>) consisting of [ ]⁺²cation and two tetraphenylborate anions, the core of the cation is assembled by four [Ni( )] units, linked to the central Ni-ion by two bridging water molecules. The resulting coordination sphere for the external symmetry related nickel ions is a pseudo octahedron.  The central Ni-atom unusually adopts dodecahedron geometry through its coordination to eight bridging water molecules. In complex (<strong>1</strong>) each Ni-atom is coordinated to one tridentate <strong>L</strong> ligand and in complex (<strong>2</strong>) each [Ni ( )] unit is coordinated to two bidentate <strong>L</strong> ligands.  Inter-and intramolecular hydrogen bonds are present in both crystal structures.</p></div>

The new title binuclear Ni (II) compound  (1) and the novel pentanuclear Ni (II) cluster {[   } (2) are formed from the reaction of an asymmetric Schiff base ligand L (L = 4-(salicylaldiminato)antipyrine) with Ni .4  in the former or Ni(ClO4)2.6H2O in presence of malonate in the later.  Complex (1) consists of ( ]+ cation) and one uncoordinated tetraphenylborate anion.  The cation adopts a distorted octahedral arrangement around each metal center.  In the binuclear unit both Ni(II) ions are linked through two phenolate (µ2-O) oxygen atoms of L, and two oxygen atoms of a  bridging carboxylate group. Each Ni (II) coordinates to four oxygen atoms at the basal plane, two oxygen atoms from two bridging phenolate groups, one from pyrazolone ring and the last of an aqua molecule, and at the axial positions to a bridging carboxylate-O atom and an azomethine nitrogen atom.  In the pentanuclear cluster (2) consisting of [ ]+2 cation and two tetraphenylborate anions, the core of the cation is assembled by four [Ni( )] units, linked to the central Ni-ion by two bridging water molecules. The resulting coordination sphere for the external symmetry related nickel ions is a pseudo octahedron.  The central Ni-atom unusually adopts dodecahedron geometry through its coordination to eight bridging water molecules. In complex (1) each Ni-atom is coordinated to one tridentate L ligand and in complex (2) each [Ni ( )] unit is coordinated to two bidentate L ligands.  Inter-and intramolecular hydrogen bonds are present in both crystal structures.