Coordination Compounds of N-(2-aminophenyl)- and N-(3-aminophenyl)pyridine-2'-carboxamide with Cobalt(II) and Cobalt(III). The Nature of Amide Deprotonation Induced by Cobalt(III) in Acidic pH

Article abstract of DOI:10.1007/BF00811265

New complexes of the general formulae CoL2X*nH2O (X=Cl, Br, I, NCS, NO3 and n=0, 1, 2 or 3), Co2L2X3*EtOH (X=Cl, Br, I, NCS),Co(DH)X2 (X=NCS, NO3) and Co(DH)2X2 (X=NCS, I) have been prepared, where LH=N-(2-aminophenyl)pyridine-2'-carboxamide and DH=N-(3-aminophenyl)pyridine-2'-carboxamide.The compounds were characterized by X-ray powder patterns, conductivity measurements, thermogravimetric analysis, magnetic properties as well as by IR, ligand field and 1H-NMR spectroscopy.In the presence of oxygen, LH undergoes a cobalt(III) ion promoted amide hydrogen ionization in the pH region 4-6. - Keywords: Amide deprotonation; Cobalt(II) complexes; Cobalt(III) complexes; Electronic spectra; IR; Magnetic moments