Effects of changes in the ligands on the skeleton and the catalytic activity of some new rhodium complexes with pyrazolato moieties

Article abstract of DOI:10.1016/0022-328X(94)88075-1

Whereas the reaction of 2 (where pz is either a pyrazolato or 3,5-dimethylpyrazolato group) with 3-(diphenylphosphino)benzoic acid and (2-formylphenyl)diphenylphosphine gives the dinuclearic complexes 2 (1 and 2) and 2 (5 and 6) respectively, 2-(diphenylphosphino)benzoic acid gives the monorhodium compounds (3 and 4).The structures of (6) have been determined by X-ray diffraction analyses.Both, the monorhodium and the dirhodium complexes catalyse the hydroformylation of acyclic and cyclic olefins at 120 deg C and at CO and H2 pressures of 28 atm.At 70-90 deg C the dinuclear complexes with 3-(diphenylphosphino)benzoic acid moieties are substantially more active than the monorhodium compounds.Key words: Rhodium; Phosphine; Hydroformylation; X-ray diffraction