Synthesis and structure of some zinc and cadmium 1,2-cyclohexanedione dioximines

The complexes [Zn(CH3COO)2(NioxH2)(DMF)(H2O)] (I), [Cd(CH3COO)2-(NioxH2)(DMF)(H2O)] (II), [Zn(CH3COO)2(NioxH2)(S-Nia)(H2O)] · DMF (III), [Zn(CH3COO)2(NioxH2)(Nia)(H2O)] (IV), and [Zn(CH3COO)2(NioxH2)(INia)(H2O)] (V), where NioxH2 is 1,2-cyclohexanedione dioxime, S-Nia is thionicotinamide, Nia is nicotinamide, and INia is iso-nicotinamide, were prepared and investigated. Compounds I–III were studied by X-ray diffraction (CCDC nos. 1505280–1505282 for I–III, respectively). Testing of zinc complexes containing various ligands demonstrated that at the optimized concentration (5 mg/L), they can be used for stimulating biosynthesis of both standard (57.14%, pH 4.7) and acid-labile (17.63%, pH 2.5) amylases by the micromycete Aspergillus niger CNMN FD 06 without affecting the duration of producer culturing.