Synthesis and characterization of imide-derived hydroxamic acids and their complexes

In this study, 3 new hydroxamates and metal complexes were synthesized and characterized by using phthalimide and saccharin molecules which are low molecular weight imide compounds as a starting material. For this purpose, ethyl phthalimide-N-acetate, ethyl saccharin-N-acetate and ethyl saccharin-N-butanoate esters of the starting materials were synthesized and converted to phthalimide-N-acetohydroxamic acid, sodium saccharin-N-acetohydroxamate and sodium saccharin-N-butanohydroxamate salts. In the second step, corresponding metal complexes were prepared by reaction of the synthesized ligands with metal sulfate salts. The structures of the synthesized ligands and complexes were characterized by elemental analysis, IR, 1H-NMR, 13C-NMR, mass spectroscopy and thermal analysis studies. In addition, spin magnetic moments were calculated by measuring the magnetic susceptibilities of the complexes. As a result, metal:ligand ratios were found as 1:1 in the complexes of phthalimide-N-acetohydroxamic acid, saccharin-N-acetohydroxamate and Cu and Zn complexes of saccharin-N-butanohydroxamate, 1:2 in Ni and Cd complexes of saccharin-N-butanohydroxamate. The complexes contain different numbers of water molecules. It was determined that the synthesized ligands had an inhibitory effect, although not high, against the tyrosinase enzyme.