Solid state coordination chemistry: structural consequences of variations in tether length in the oxovanadium–copper–bisterpy–{O3P(CH2)nPO3}4− system, n = 1–6 (bisterpy = 2,2′:4′,4″:2″,2‴-quarterpyridyl-6′,6″-di-2-pyridine)

Abstract

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⁺/V_xO_yⁿ⁻/{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(CH₂)₃PO₃}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.