Secondary metal-ligand cationic subunits {ML}n+ as structural determinants in the oxovanadium/phenylphosphonate/{ML}n+ system, where {ML} is a Cu2+/organonitrogen moiety

The hydrothermal reactions of CuSO4 center dot 5H(2)O, Na3VO4, phenylphosphonic acid and the appropriate organonitrogen ligand yield a series of materials of the oxovanadium/ phenylphosphonate/ Cu(II) - ligand family. The structural influences of the organonitrogen ligand are most pronounced in the dimensionality of the material. Thus, [{Cu( phen)} VO(O3PC6H5)(2)] center dot 0.5 H2O ( 1) is one-dimensional; [{Cu-2( bpytrz)(H2O)} VO(O3PC6H5)(2)(HO3PC6H5)] ( 2) (bpytrz = 3,5-di-2-pyridyl-1,2,4-triazolate) is two-dimensional, and [{Cu(4,4'-bpy)}(0.5)VO2(O3PC6H5)] ( 3) is three-dimensional. When the phenylphosphonate component is replaced by phenyl-1,2-diphosphonate, the three-dimensional material [{Cu(4,4'-bpy)} VO2(HO3PC6H4PO3)] ( 4) is obtained. In contrast to the structure of 3 which exhibits a three-dimensional Cu - V - P - O substructure which encapsulates the {Cu-2(bpy)}(4+) unit, 4 exhibits the more common "pillared'' layer structure with Cu - V - P - O networks buttressed by the 4,4'-bipyridyl groups. When the starting materials that gave 4 are reacted at 200 degrees C rather than 120 degrees C, the copper phase [{Cu(4,4'-bpy)(0.5)}{Cu(H2O)}(O3PC6H4PO3)] center dot H2O (5) is obtained. Compound 5 exhibits a "pillared'' layer structure with a Cu - P - O network exhibiting embedded binuclear copper( II) sites.