Insulin-like model complexes: Synthesis, spectra characterization and crystal structure of two novel oxovanadium complexes with poly(pyrazolyl)borate ligands VO(HB(pz)3)(H2B(pz)2) and VO(B(pz)4)2

Two new oxovanadium (IV) complexes VO(HB(pz)3)(H2B(pz)2) (1) and VO(B(pz)4)2 (2) have been obtained by the reaction of oxovanadium sulfate with the corresponding ligands KHB(pz)3, KH2B(pz)2 and KB(pz)4, respectively. The two complexes were characterized by elemental analyses, IR, UV–Vis and X-ray diffraction. Complex 1 crystallizes in the orthorhombic space group, Pca21. Complex 2 crystallizes in the orthorhombic space group, Pna21. In both complexes, five nitrogen atoms and one oxygen atom coordinate to the vanadium atom, forming a distorted octahedral geometry (VON5). In addition, related spectra characterization, hydrogen-binding properties, structural configuration and quantum chemistry calculations are also discussed.