New solids from old cluster: Syntheses and structural characterization of [Zn(2,2′-bpy) 3] 2[As 8V 14O 42(H 2O)]·4H 2O and [Zn(2,2′-bpy)(dien)] 2[As 8V 14O 42(H 2O)]·2H 2O

Abstract

Two new arsenic–vanadium clusters, [Zn(2,2′-bpy) 3] 2[As 8V 14O 42(H 2O)]·4H 2O ( 1, 2,2′-bpy =2,2′-bipyridine) and [Zn(2,2′-bpy)(dien)] 2[As 8V 14O 42(H 2O)]·2H 2O ( 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, P 1 ¯ , 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 [As 8V 14O 42(H 2O)] 4- polyoxoanions and chiral [Zn(2,2′-bpy) 3] 2+ cations, while compound 2 is constructed from [As 8V 14O 42(H 2O)] 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.