Electrocatalytical reduction of bromocyclopentane and iodobenzene using Cobalt(III) and Nickel(II) Tris- and Bis-bidentates Schiff Bases Complexes

The following bidentate Schiff base: 2-[(4-Methoxybenzyl)iminomethyl]-phenol (HL), was employed as an asymmetric ligand in the synthesis of two mononuclear nickel(II) and cobalt(III) complexes (Ni(II)-2L and Co(III)-3L). This ligand has been synthesized via condensation of salicylaldehyde and 4-methoxybenzylamine in methanolic solution, while the both complexes result from complexation of metal(II) chloride hydrate salts with HL. These coordination compounds were structurally characterized by elemental analysis, FT-IR, UV-Vis, H-1 NMR and C-13 NMR spectral studies. Moreover, the electrochemical properties of both complexes were studied by cyclic voltammetry in DMF solution containing 0.1 M tetra-n-butylammonium tetrafluoroborate (Et4NBF4). This study reveals that each complex showed successively two redox couples: M(III)/M(II) and M(II)/M(I). Finally, the electrocatalytic activity of these complexes has been examined and it has been found that the both complexes worked as effective homogeneous electrocatalysts for the electroreduction of bromocyclopentane and iodobenzene using glassy carbon as working electrode.