Reductive electrochemical study of Ni(II) complexes with N2O2 Schiff base complexes and spectroscopic characterisation of the reduced species. Reactivity towards CO

摘要: Abstract Reductive electrochemical properties of series nickel(II) complexes with salen ligands, which have different diimine bridges and substituents in the aldehyde moiety been studied several solvents (CH3CN, dmf (CH3)2SO). In order to assess relative importance Ni(I) Ni(II) anion radical species, reduced species characterised by combining EPR UV–Vis spectroscopy. The results shown that aliphatic are four-coordinate a B1g (dxy)1 ground state, whereas those aromatic square–planar rapidly dimerise. None was found bind pyridine, imidazole triphenylphosphine, but presence stronger π-acceptor ligand CO, new were formed that, on basis data, can be formulated as five-coordinate [NiL·CO]−. These more stable than parent confirmed positive E1/2 values consequence extensive π delocalisation M→CO.