In Situ Ligand Reactions under Hydrothermal Conditions Afford a Novel Zinc-Substituted Polyoxovanadate Dimer

A novel polyoxovanadate (POV), [Zn(2,2‘-bpy)3]4[(ppz){{Zn(tepa)}2ZnAs8V13O41(H2O)}2][As8V14O42(0.5H2O)]2·4H2O
(1, 2,2‘-bpy = 2,2‘-bipyridine, ppz = piperazine, tepa = tetraethylenepentamine), has been hydrothermally
synthesized and structurally characterized by elemental analysis, IR spectra, thermogravimetric analysis, magnetic
measurement, and single-crystal X-ray diffraction analysis. Crystal data for 1:  orthorhombic, Aba2, a = 28.3414(14) Å, b = 27.9995(16) Å, c = 41.5819(16) Å, V = 32997(3) Å3, Z = 4, ρ = 2.264 mg·cm-3. X-ray structure
analysis shows that the structure of 1 consists of one unique zinc-substituted POV dimer and two POV monomers.
Interestingly, the formation of the zinc-substituted POV dimer involves two new in situ ligand reactions under
hydrothermal conditions, the intermolecular and intramolecular deamination coupling reactions of dien. Magnetization
measurement revealed the presence of antiferromagnetic interaction between VIV ions in 1.