Sugar hydrazone–metal complexes: transition- and non-transition metal complexes of monosaccharide S-alkylhydrazonecarbodithioates and dehydro-l-ascorbic acid bis(S-alkylhydrazonecarbodithioates)

Copper(II), nickel(II) and palladium(II) complexes with aldehydo-d-arabinose-, l-arabinose-, d-galactose-, d-glucose- and d-mannose- S-methyl- and S-benzylhydrazonecarbodithioates were synthesized and characterized by elemental analyses, infrared and UV–Vis. In these complexes the aldehydo sugar hydrazone acts as a mononegative NS bidentate ligand. The reaction of Cu(II) chloride, however, proceeded with reduction, and copper(I) complexes were isolated. The hydrazone molecule in these Cu(I) complexes acts as neutral NS bidentate ligand. Dehydro-l-ascorbic acid bis(S-methylhydrazinecarbodithioate) and bis(hydrazinecarbothioamide), as well as their corresponding Cu(II), Ni(II), zinc(II) and Pd(II) complexes were prepared and characterized. Electrospray (ES) and field desorption (FD) mass spectra suggest that the Cu(II), Ni(II), and Pd(II) complexes are monomeric (square planar), whereas the Zn(II) are dimeric and pentacoordinate.