Solid state coordination chemistry: structural consequences of variations in tether length in the oxovanadium–copper–bisterpy–{O 3 P(CH 2 ) n PO 3 } 4− system, n = 1–6 (bisterpy = 2,2′:4′,4″:2″,2‴-quarterpyridyl-6′,6″-di-2-pyridine)

Hydrothermal reactions of Na3VO4, an appropriate Cu(II) source, bisterpy and an organodiphosphonate, H2O3P(CH2)nPO3H2 (n = 1-6) yielded a family of materials of the type [Cu2(bisterpy)]4+/VxOy(n-)/[O3P(CH2)nPO3]4-. This family of bimetallic oxides is characterized by an unusual structural diversity. The oxides [[Cu2(bisterpy)]V2O4[O3PCH2PO3H]2] (1), [[Cu2(bisterpy)(H2O)]VO2[O3P(CH2)3PO3][HO3P(CH2)3PO3H2]] (4) and [[Cu2(bisterpy)]V2O4[O3P(CH2)6PO3H]2].2H2O (7.2H2O) are one-dimensional, while [[Cu2(bisterpy)(H2O)2]V2O4[O3P(CH2)2PO3][HO3P(CH2)2PO3H]2] (2), [[Cu2(bisterpy)]V4O8[O3P(CH23PO3]2].4H2O (3.4H2O) and [[Cu2(bisterpy)]V2O4(OH)2[O3P(CH2)4PO3]].4H2O (5.4H2O) are two-dimensional. The V(IV) oxide [[Cu2(bisterpy)]V4O4[O3P(CH2)5PO3H]4].7.3H2O (6.7.3H2O) provides a relatively unusual example of a three-dimensional bimetallic oxide phosphonate. The structures reveal a variety of V/P/O substructures as building blocks.