Département de chimie moléculaire

Two new dinucleating phenol-based ligands (m-HLSMe and p-HLSMe) bearing pyridine-contg. pendant arms with a SMe group on one pyridine (meta or para position relative to the pyridine nitrogen atom) were synthesized. After coordination by two copper(II) ions, the corresponding $μ$-phenoxido, $μ$-hydroxido dicopper(II) complexes were isolated and characterized by UV/visible, EPR spectroscopy, single-crystal x-ray anal. (for the complex with the SMe substituent at the meta position) and electrochem. The presented compds. mimic the active site of type 3 copper enzymes and in particular the distinct environments of the copper ions. Both complexes are active as catalysts for the oxidn. of 3,5-di-tert-butylcatechol to the resp. quinone. The catalytic properties of the complexes depend on substrate binding, as reflected by the KM values detd. for the complexes in presence of 3,5-dtbc and are not correlated directly with the redox properties of the dicopper center. [on SciFinder(R)]