Solid state coordination chemistry of the copper(II)-terpyridine/ oxovanadium organophosphonate system: Hydrothermal syntheses, structural characterization and magnetic properties

The hydrothermal reactions of CuSO ₄·5H ₂O, Na ₃VO ₄, 2,2′:6′:2″-terpyridine (terpy), and the appropriate organophosphonate ligand yield a series of materials of the Cu(II)-terpy/oxovanadium organophosphonate family. The complexes exhibit distinct structures spanning one-, two- and three-dimensions and exhibiting diverse oxovanadium building blocks. Thus, [{Cu(terpy)}(V ₂O ₄)(O ₃PPh)(HO ₃PPh) ₂] (1) is one-dimensional and constructed from binuclear units of corner-sharing V(v) square pyramids. While [{Cu(terpy)}VO(O ₃PCH ₂PO3)] (2), [{Cu(terPy)} ₂(V ₄O ₁₀)(O ₃PCH ₂CH ₂PO ₃)] (3), and [{Cu(terPy)}(V ₂O ₄){O ₃P(CH ₂) ₃PO ₃}]·2.5H ₂O (4-2.5H ₂O) are similarly one-dimensional, the V/O structural components consist of isolated V(iv) square pyramids, tetranuclear V(v) units of three tetrahedra and one square pyramid in a corner-sharing arrangement, and isolated V(v) tetrahedra and square pyramids, respectively. The second propylenediphosphonate derivative, [{Cu(terpy)}(V ₂O ₄){O ₃P(CH ₂) ₃PO ₃}] (5) is three-dimensional and exhibits isolated V(v) tetrahedra as the vanadate component. The two-dimensional structure of [{Cu(terpy)(H ₂O)}(V ₃O ₆){O ₃P(CH ₂) ₄PO ₃}] (6) is mixed valence with isolated V(iv) square pyramids and binuclear units of corner-sharing V(v) tetrahedra providing the V/O substructures.