HETEROGENIZED CATALYSTS FOR OLEFIN HYDROFORMYLATION CONTAINING COBALTAND PALLADIUM-COBALT COMPLEXES ANCHORED ON PHOSPHINATED SIO2 - A C-13SOLID-STATE NMR-STUDY

C-13 solid-state NMR technique with high-power fl decoupling was emplo yed to study heterogenized hydroformylation catalysts containing the a nchored complexes of general composition =Si-P2Co2(CO)(6.6) and =Si-P2 PdCo2(CO)(7.8) (where =Si-P-2 is the diphosphine ligand covalently bon ded to a silica surface), The data on the content and state of complex ed CO are compared with those obtained earlier by IR. The values of ch emical shift anisotropy provide information on the molecular motion of anchored metal carbonyl fragments, Evidence is presented for the fast restricted motion of these fragments which is not typical for the sup ported metal crystallites. The interaction of CO, H-2, and ethylene wi th the anchored Co and Pd-Co carbonyl complexes were studied to identi fy the species which might act as intermediates in hydroformylation re action. During these studies, the resonances attributed tentatively to pi-bonded ethylene and surface propionyls were observed. Based on the data obtained, we discuss the mechanism of action of Co and Pd-Co cat alysts, as well as the reasons of the observed Pd-Co synergism.