A square-planar nickel(II) monoradical complex with a bis(salicylidene)diamine ligand

Benisvy, L., Kannappan, R., Song, Y.-F., Milikisyants, S., Huber, M., Mutikainen, I., Turpeinen, U., Gamez, P., Bernasconi, L., Baerends, E. J., Hartl, F. ORCID: https://orcid.org/0000-0002-7013-5360 and Reedijk, J. (2007) A square-planar nickel(II) monoradical complex with a bis(salicylidene)diamine ligand. European Journal of Inorganic Chemistry, 2007 (5). pp. 637-642. ISSN 1434-1948 doi: 10.1002/ejic.200601015

Abstract/Summary

The new square-planar Ni-II-N2O2 complex [Ni(L-Me)] (1(Me)), where L-Me, stands for the dianionic phenolato form of N,N'bis(3,5-di-tert-butyl-salicylidene)-4,5-dimethyl-1,2-phenyl- enediamine ((LH2)-L-Me), has been synthesised and fully characterised. X-ray crystallography was also used for the characterisation. The electrochemical one-electron oxidation of 1(Me) produces the thermally stable (within the temperature range 10-295 K) cationic species (1(Me))(+). The UV/Vis and X-band EPR experimental data, supported by DFT calculations, indicate that (1(Me))(+), is best described as a Ni-II monoradical complex and, thus, does NOT exist in a Ni-III ground state, in contrast to its demethylated counterpart [Ni(L-H)](+) (1(H))(+) below 170 K.