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The synthesis and characterisation of phenolate complexes of Cu(II) and Ni(II) that are capable of supporting a phenoxyl radical ligand
- Source :
-
Inorganica Chimica Acta . Jan2007, Vol. 360 Issue 1, p203-211. 9p. - Publication Year :
- 2007
-
Abstract
- Abstract: New CuII and NiII complexes of potentially tridentate N2O Schiff base ligands 1 and 2 have been synthesised and characterised. [Cu(2)(OH2)]+ possesses a square planar geometry in the solid state whereas [Ni(1)2] possesses a distorted octahedral geometry in which the amine donors of 1 coordinate weakly to the NiII centre. EPR spectroscopy demonstrates that the N2O2 coordination sphere of [Cu(2)(OH2)]+ is retained in CH2Cl2 solution. [Cu(2)(OH2)]+ exhibits a reversible one electron oxidation at E 1/2 =0.54V versus [Fc]+/[Fc], the product of which has been characterised by UV–Vis absorption and EPR spectroscopies. The spectroscopic signature of the oxidised product is consistent with the formation of a stable phenoxyl radical ligand bound to a CuII centre. [Ni(1)2] possesses a reversible metal-based oxidation process at E 1/2 =0.03V versus [Fc]+/[Fc] and a further oxidation, attributed to the generation of a phenoxyl radical centre, at =0.44V versus [Fc]+/[Fc]. UV–Vis absorption and EPR spectroscopic studies indicate that the lower potential process is a formal NiIII/II couple. In contrast, the pro-ligands 1H and 2H exhibit chemically irreversible oxidation processes at =0.42 and 0.40V versus Fc+/Fc, respectively, and do not support the formation of stable phenoxyl radical species. [Copyright &y& Elsevier]
- Subjects :
- *OXIDATION
*ABSORPTION
*INDUSTRIAL chemistry
*SPECTRUM analysis
Subjects
Details
- Language :
- English
- ISSN :
- 00201693
- Volume :
- 360
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Inorganica Chimica Acta
- Publication Type :
- Academic Journal
- Accession number :
- 23364591
- Full Text :
- https://doi.org/10.1016/j.ica.2006.07.057