[Ni(H2O)6]2[Na(H2O)3]2[V10O28]·4H2O,bis(nickel hexahydrate) bis(sodium trihydrate) decavanadate tetrahydrate

Polyoxometallates are capable of including transition metals in their crystal structures as either discrete cations or heteroatoms. The title compound crystallizes with triclinic symmetry and consists of a centrosymmetric [V₁₀O₂₈]^6? anion, a trimeric {[Na(H₂O)₃][Ni(H₂O)₆][Na(H₂O)₃]}⁴⁺ cation, an [Ni(H₂O)₆]²⁺ cation and four water molecules of crystallization. The compound possesses two Ni atoms (each on independent inversion centres), one as a discrete cation and one in a disodium–nickel trimeric cation involved in the one‐dimensional polycation–polyanion hybrid polymer. The polymers are bound together via hydrogen bonds to the water mol­ecules and the nickel(II) hexahydrate cation. Several structures of decavanadate compounds having transition metal atoms, monovalent cations and [V₁₀O₂₈]^6? anions in the ratio 2:2:1 have been reported previously. However, the present compound differs from these in its arrangement of monovalent cations and transition metal atoms.     

Synthesis and magnetic properties of nickel(II) triazamacrocyclic complexes. Crystal structure of [Ni(Me3[12]N3)(O2N)(H2O)]-(ClO4)·2H2O

Summary The synthesis, properties and X-ray crystal structure of [Ni(Me₃[12]N₃)(O₂N)(H₂O)](ClO₄)·2H₂O, in which Me₃[12]N₃ is 2,4,4-trimethyl-1,5,9-triazacyclododec-1-ene, are described. The Ni atom is octahedrally coordinated to three N atoms of the macrocycle, two O atoms of the nitrito group and one H₂O molecule. Monomeric units are linked by hydrogen bonds through one of the water of crystallization molecules, forming a chain. Magnetic measurements between 290 and 4 K reveal slight antiferromagnetic behaviour.