Premium
Copper(II)‐Coordinated α‐Azophenols: Effect of the Metal‐Ion Geometry on Phenoxyl/Phenolate Oxidation Potential and Reactivity
Author(s) -
Kochem Amélie,
Carrillo Alexandre,
Philouze Christian,
van Gastel Maurice,
du Moulinet d'Hardemare Amaury,
Thomas Fabrice
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201402312
Subject(s) - chemistry , tetracoordinate , reactivity (psychology) , electron paramagnetic resonance , coordination geometry , coordination sphere , copper , inorganic chemistry , quinoline , steric effects , cyclic voltammetry , photochemistry , chloride , redox , benzyl alcohol , crystallography , medicinal chemistry , stereochemistry , electrochemistry , molecule , crystal structure , organic chemistry , hydrogen bond , catalysis , nuclear magnetic resonance , alternative medicine , computer graphics (images) , pathology , computer science , planar , medicine , physics , electrode
Two copper(II) complexes were synthesized from tridentate ligands involving a (N quinoline ,N azo ,O phenol ) 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 CH 2 Cl 2 display a reversible oxidation wave at E 1/2 = 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.