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

Resumo

Three mononuclear different-ligand Zn(II) complexes, [Zn(CH₃COO)₂(PaoH)₂] (I), [Zn(PaoH)₂(DMSO)₂][BF₄]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 P2₁/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 N₄O₂ sets of donor atoms in I and II and by N₆ 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.