Electrochemical synthesis of MII complexes with a schiff base containing an amido group. Crystal structure of a cobalt(II) complex with a reorganised ligand

Article abstract of DOI:10.1002/zaac.200570034

M(HL)(H₂O)_n complexes have been obtained by the electrochemical reaction of Fe, Co, Ni, Cu, Zn and Cd anodes with the potentially pentadentate and trianionic asymmetrical Schiff base 3-aza-N-{2-[1-aza-2-(5-nitro-2-hydroxylphenyl)-vinyl]phenyl}-4-(5-nitro-2- hydroxyphenyl)but-3-enamide (H₃L), containing a hard amido donor atom. The complexes have been characterized by elemental analysis, mass spectrometry, IR and ¹H NMR spectroscopies, magnetic measurements and molar conductivities. Co(HL)(H₂O) (2) has been found to rearrange in DMF solution into a crystallographically solved octahedral complex, CoL ¹(H₂O)₂ (7) [where H₂L¹ is the symmetrical Schiff base ligand N, N′-(1,2-phenylene)-bis(5-nitro-3- hydroxysalicylidenimine)]. A hydrolysis mechanism is discussed to explain this rearrangement.