A new molybdenum(V) nickel phosphate based on divacant[H_(30)(Mo~v_(16)O_(32))Ni_(14)(PO_4)26O_2(OH)_4(H_2O)8]~(12-)wheelt

摘要

A new molybdenum nickel phosphate, [H_2en]_3Na_4[Ni(H_2O)_3][H_(30)(Mo~v_(16)O_(32))Ni_(14)(PO_4)_(26)O_2(OH)_4(H_2O)_8].8H_2O1, has been hydrothermally synthesized and structurally characterized. Compound1 crystallizes in the monoclinic space group P2_1 /c witha=18.6118(6) A,b =20.9879(6) A, c =22.9360(5) A, β = 116.678(2)°, V = 8005.5(4) A~3andZ =2. The polyoxoanion of 1 exhibits an unusualdivacant wheel-type cluster in which two {NiO_6} octahedra are lost from the well-known "saturated"{Mo_(16)TM_(16)P_(26)} wheel. The two vacant sites are occupied by two protonated ethylenediamines (H_2en)via the strong hydrogen-bonding interactions between the surface O atoms of the polyoxoanions andthe amine group derived from the H_2en ligands. DC susceptibility measurements show that compound1 exhibits strong antiferromagnetic interactions inside the wheel-type cluster.