A new 2-D layer-like organic-inorganic hybrid tungstobismuthate constructed from [Bi2W20O70]14− units and dimeric [Cu2(dien)2]24+ complex cations

The reaction of the lacunary polyoxotungstate [B-α-BiW9O33]9− with Cu(Ac)2·H2O in the presence of diethylenetriamine under hydrothermal conditions generating a new 2-D layer-like organic-inorganic hybrid tungstobismuthate [Cu(dien)(H2O)]2[Cu2(dien)2]2H2[Bi2W20O70]·15H2O (1) (dien = diethylenetriamine). 1 has been carefully characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis (TGA), X-ray single-crystal diffraction. 1 crystallizes in the orthorhombic Pbca space group with a = 21.077(2) Å, b = 21.788(2) Å, c = 22.821(2) Å, V = 10480.1(17) Å3, Z = 4, GOOF = 1.043, R1 = 0.0454, wR2 = 0.0710. Structural analyses show that 1 exhibits an organic-inorganic hybrid 2-D layer-like architecture constructed by [Bi2W20O70]14− polyanions by means of the [Cu2(dien)2]4+ bridges. Notably, the dien ligand presents two kinds of coordination modes in 1, which has been rarely observed in previously reported polyoxometalates. The magnetic study of 1 demonstrates the existence of ferromagnetic coupling interactions between Cu2+ ions in dimeric [Cu2(dien)2]4+ groups.