New solids from old cluster: Syntheses and structural characterization of [Zn(2,2′-bpy)₃]₂[As₈V₁₄O ₄₂(H₂O)]·4H₂O and [Zn(2,2′-bpy) (dien)]₂[As₈V₁₄O₄₂(H ₂O)]·2H₂O

Two new arsenic-vanadium clusters, [Zn(2,2′-bpy)₃] ₂[As₈V₁₄O₄₂(H₂O)] ·4H₂O (1, 2,2′-bpy =2,2′-bipyridine) and [Zn(2,2′-bpy)(dien)]₂[As₈V₁₄O ₄₂(H₂O)]·2H₂O (2, dien= diethylenetriamine), have been hydrothermally synthesized and characterized by IR, elemental analysis, EPR, XRD, TGA, magnetic measurements, and single-crystal X-ray diffraction analysis. Crystal data: 1, triclinic,P1̄, a=14.3793(2) Å, b=16.7706(2) Å, c=24.7077(1) Å, α=93.740(1)°, β=93.182(1)°, γ=113.363(1)°, Z=2; 2 orthorhombic, P4(3)2(1)2, a=21.3442(7) Å, b=21.3442(7) Å, c=15.8837(7) Å, Z=4. X-ray crystallographic study showed that compound 1 is composed of the discrete [As₈V₁₄O₄₂(H₂O)]^4- polyoxoanions and chiral [Zn(2,2′-bpy)₃]²⁺ cations, while compound 2 is constructed from [As₈V₁₄O ₄₂(H₂O)]^4- cluster anions and novel [Zn(2,2′-bpy)(dien)]²⁺ complex fragments linked through hydrogen bonds into a network. Variable temperature susceptibility measurements demonstrate the presence of antiferromagnetic interaction between V^IV cations in 1 and 2.