Synthesis and properties of cobalt(III) complexes of tripodal ligands containing amide functional groups

Two new, trigonally symmetrical, triamide tripodal ligands and their complexes with the cobalt(III) ion, [1,1,1-tris(4-amino-1-oxo-2-azabutyl)ethanato]cobalt(III)trihydrate 1 and [1,1,1-tris(4-amino-4-methyl-3-oxo-2-azapentyl)- ethanato]cobalt(III)-water-ethanol (1/8/0.5) 2 have been prepared. The hexadentate structures of the neutral. trigonal, triamido complexes have been established by an X-ray study of 1 and C-13 NMR spectrometry of both molecules. The chemical, spectroscopic and electrochemical properties of the complexes have been investigated as well as those of the monoamido tripodal complex [1,9-diamino-5-(4-amino-2-azabutyl)-5-ethoxycarbonyl-4-oxo-3,7-diazanonanato]cobalt(III) chloride.