Catalyseurs D'Oxydation I. Influence De La Coordinence Sur L'Activité Des Chélates D'Éléments De Transition

Abstract

AbstractDifferent chelates of the transition elements, resembling to the metallic enzymes, were investigated for their catalytic activities in the oxidation, by molecular oxygen (1 atm) at 100°C., of liquid cumene. Cumylhydroperoxide is the main product. Catalytic activity was measured from the increase of the rate of reaction, and the decrease of the yield in hydroperoxide (relatively to the amount of cumene transformed) following the use of the catalyst. The ligands of Co (II), Ni (II.), Mn (II,), Cu (II), Fe (II) and Cr (III) were (successively: the ligand, the ratio ligand: cation, and the coordinence of the chelate: 1) salicylaldehyde ethylenediimine, 1:1, 4; 2) diazoic pigments, 2:1, 6; 3) formazylic complexes, 1:1, 4. Comparison has been made between the activities of these chelates, and that of the corresponding naphtenate and stearate. The chelates of the same cation bound to different ligands have equal activities when the coordinence is the same. The relative catalytic activities of the complexes—of the same cation—of coordinence 2, 4, and 6 are respectively about 4, 5, 3, and 1.