Synthesis and structure of mononuclear zinc complexes with pyridine-2-aldoxime

Three mononuclear different-ligand Zn(II) complexes, [Zn(CH 3 COO) 2 (PaoH) 2 ] ( I ), [Zn(PaoH) 2 (DMSO) 2 ][BF 4 ] 2 ( II ), and [Zn(NCS) 2 (PaoH) 2 ] ( III ) (DMSO = dimethylsulfoxide) were prepared by the reaction of zinc acetate and tetrafluoroborate with pyridine-2-aldoxime (PaoH). The composition and structure of the complexes were confirmed by IR spectroscopy and X-ray diffraction. All compounds crystallize in the monoclinic system, compounds I and II have space group P2 1 / n , while compound III has space group C2/ c . In all compounds, the Zn coordination polyhedron is a distorted octahedron, which is formed by the N 4 O 2 sets of donor atoms in I and II and by N 6 in III . Complex I in the optimal concentration of 5–10 mg/L was found to stimulate the biosynthesis of standard (pH 4.7) amylases by the micromycete Aspergillus niger CNMN FD 06.