Crystal structures of oxalato and oxamido polyaminecobalt(III) complexes produced by hydrolysis of monooxamide

The reactions of sodium monooxamide (H2NCOCO2Na) with trans-[Co(en)(2)Cl-2] Cl, trans-[Co(3,2,3-tet)Cl-2]Cl (3,2,3-tet = 1,5,8,12-tetraazadodecane), ci s-alpha-[Co(trien)Cl-2]Cl and [Co(tren)Cl-2]Cl result in the formation of [ Co(en)(2)(ox)]Cl . 4H(2)O (1), cis-beta-[Co(3,2,3-tet)(ox)]Cl . 4 H2O (2), cis-alpha-[Co(trien)(ox)]Cl . 2 H2O (3), and [Co(tren)(ox)](ClO4) . 0.5 H2O (4) respectively, implying a hydrolytic cleavage of the amide bond. [Co(tr en) (O,O'-oxam)]Cl-2 . 2 H2O (5) (oxam = H2NCOCO2-) and p-[Co(tren) (NH3)(O -oxam)]Cl-2 (6) have also been prepared in order to give mechanistic inform ation for the hydrolysis of monooxamide. Crystal structures of the products are reported and possible pathways for the hydrolysis reactions are discus sed.