1263777-05-4Relevant academic research and scientific papers
Copper(II)-coordinated α-Azophenols: Effect of the metal-ion geometry on phenoxyl/phenolate oxidation potential and reactivity
Kochem, Amélie,Carrillo, Alexandre,Philouze, Christian,Van Gastel, Maurice,Du Moulinet D'Hardemare, Amaury,Thomas, Fabrice
, p. 4263 - 4267 (2014)
Two copper(II) complexes were synthesized from tridentate ligands involving a (Nquinoline,Nazo,Ophenol) donor set. The copper(II) ion is tetracoordinate with a chloride ion occupying the fourth position of the coordination sphere. Both X-ray diffraction and electron paramagnetic resonance (EPR) spectroscopy reveal that the copper(II) ion geometry is square planar in 1. In contrast, significant tetrahedral distortions are observed in 2, as a result of the steric clash between the hydrogen atoms of the methyl substituent of the quinoline group and the chloride ion. Cyclic voltammetry curves of 1 and 2 in CH2Cl2 display a reversible oxidation wave at E1/2 = 0.59 V and 0.56 V versus ferrocenium/ferrocene, respectively, which was assigned to the phenoxyl/phenolate redox couple. Compounds 1+ and 2+ were generated and characterized by UV/Vis and EPR spectroscopy. Their reactivity with benzyl alcohol was investigated by kinetic measurements. Tetrahedral distortion at the metal ion in a copper(II) complex containing tridentate ligands with a (Nquinoline,Nazo,Ophenol) donor set is tuned by the α-quinoline substituent. The CuII-phenoxyl radical species oxidizes benzyl alcohol at rate constants that are essentially independent of the distortion at the metal center.
