Hybrid inorganic-organic 1-D and 2-D frameworks with {as₈V ₁₄O₄₂} clusters as building blocks

Three novel hetero-polyoxovanadates, [Cd(2,2′-bpy) ₃]{[Cd(dien)]As₈V₁₄O₄₂(H ₂O)} (1, 2,2′-bpy=2,2′-bipyridine, and dien=diethylenetriamine), [Zn(2,2′-bpy)₂]₂[As ₈V₁₄O₄₂(H₂O)]·H₂O (2) and [Ni(en)₂]₃[As₈V₁₄O ₄₂(HPO₃)]·4H₂O (3, en=ethlenediamine), were hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Crystal data: 1 monoclinic, P2(1)/n, a=15.1728(5), b=19.2863(5), c=25.7122(9)Å, β=96.005(2)°, Z=4. 2, orthorhombic, P2(1)2(1)2(1), a=12.1270(3), b=15.8678(8), c=40.0422(1)Å, Z=4. 3, triclinic, P1&O|, a=12.9340(3), b=13.4130(3), c=21.1820(4)Å, α=87.170(3)°, β=77.517(3)°, γ=68.480(3)°, Z=2. Compounds 1-3 are all made of the {As₈V₁₄O₄₂} shells linked by corresponding transition metal complexes into extended structures. Compound 1 and 2 present 1-D wave-like and tubular structures, respectively, while compound 3 exhibits a novel 2-D structure containing interwinding puckery layers. Variable temperature susceptibility measurements demonstrate the presence of antiferromagnetic interaction between V^IV cations in 1 and 2.