Two Metal Complexes Supported by {VO₃}_n ⁿ⁻ Chains: Hydrothermal Syntheses and Crystal Structures of [M(dpa)V₂O₆] (M = Zn(II) and Cu(II); dpa = 2,2′-dipyridylamine)

Abstract

Two new metal complexes supported by {VO₃}_n ⁿ⁻ chains, [M(dpa)V₂O₆] (1, M = Zn²⁺; 2·H₂O, M = Cu²⁺; dpa = 2,2′-dipyridylamine), have been synthesized hydrothermally and characterized by elemental analysis, TG analysis, IR spectroscopy and single-crystal X-ray diffraction. Crystal data: [Zn(dpa)V₂O₆] 1, Triclinic, P-1, a = 9.663(7) Å, b = 10.617(7) Å, c = 15.114(10) Å, α = 105.678(10)°, β = 104.772(9)°, γ = 94.021(10)°, Z = 2; [Cu(dpa)V₂O₆]·H₂O 2·H₂O, Monoclinic, C2, a = 20.543(3) Å, b = 7.2460(9) Å, c = 10.4853(13) Å, β = 111.318(2)°, Z = 4. Complex 1 is constructed from sinusoidal {VO₃}_n ⁿ⁻ chains with {Zn(dpa)}²⁺ fragments spanning the adjacent troughs and crests into an 1D ribbon-like structure. Complex 2 is built up by linking {VO₃}_n ⁿ⁻ chains via pairs of symmetrical {Cu(dpa)}²⁺ fragments into a 2D layered structure. The Zn(II) and Cu(II) ions exhibit tetrahedral and square pyramidal coordination environments, respectively. The formation of the two isomers is attributed to the flexibility of {VO₃}_n ⁿ⁻ chains and the different coordination configurations of the two metal ions. There exist significant π–π stacking and hydrogen bonding interactions in complexes 1 and 2.

Index Abstract

Single crystal X-ray diffraction analysis reveals that two new metal complexes, [M(dpa)V₂O₆] (1, M = Zn²⁺; 2·H₂O, M = Cu²⁺; dpa = 2,2′-dipyridylamine), are constructed from {VO₃}_n ⁿ⁻ chains and {M(dpa)}²⁺ fragments into 1D and 2D structures.