Coordination compounds of Co(II) assembled through deprotonation-protonation of the ligand

The process of deprotonation-protonation of the Schiff base 2,6-diacetylpyridine bis(isonicotinoylhydrazone) in the coordination compounds of Co(II) was studied, as a method for the synthesis of new complexes. Five new coordination compounds were obtained, of which in three complexes the Schiff base coordinates in neutral form (H2L) - [Co(H2L)(H2O)2]X2 (X = ClO4- , Cl- , Br- ), and in two complexes the ligand is bis-protonated (H4L2+) - [Co(H4L)(H2O)2](HSO4)4 and [Co(H4L)(SO4)(H2O)]SO4·2,5H2O. The chemical and structural composition were determined by the methods of elemental analysis, IR spectroscopy and single crystal X-ray diffraction.