SYNTHESIS, SPECTROSCOPIC AND X-RAY CRYSTAL STUDIES OF MIXED-CHELATE COPPER(II) COMPLEXES CONTAINING A NOVEL BETA-DIKETONATE LIGAND

Mixed-chelate copper(II) complexes, [CuL(tmed)]X (where L = a beta-dik etonate derived from 2,4-diacetyl-5-hydroxy-5-methyl-3-phenyl tmed = N ,N,N', N'-tetramethylethylenediamine and X = NO3 or BPh(4)) were prepa red and studied by conductivity (NO3 only), UV-vis and ESR techniques. The crystal structure of the nitrate complex was determined by X-ray diffraction. It consists of a mononuclear square-planar copper(II) com plex cation and a nitrate counterion which is not coordinated to coppe r. The rate enhancement effects of [CuL(tmed)]NO3 on the autooxidation of 3,5-di-tert-butylcatechol in acidic solutions are compared with th ose of other similar copper(II) complexes.