Preparation Of Phosphine-Rhodium Complexes For Hydroformylation Of Higher Olefins

The present dissertation sets the hydroformylation of higher olefins as the object of study. Works have been focused on the development of novel catalyst system. The significant results are described as follows:1. A series of bidentate P,N ligands were synthesized by reductive amination with 2-(diphenylphosphino)benzaldehyde and different alkyl-amines; On the other hand, on the basis of successful syntheses of a linear chain alkyl(diphenyl)phosphine and three alkyl-substituted triphenylphsophines, a series of amphiphilic phosphines were prepared with oleum in high yields. The structures and physical-chemical properties of the above ligands and their rhodium complexes were characterized systemically.2. The coordination of phosphine and nitrogen atoms with rhodium was observed by using the bidentate P,N ligands. The shorter of the chain in the structure of P,N ligand, the higher activity of 1-hexene hydroformlylation with aminophosphine rhodium complexes. The addition of appropriate water to the catalyst system caused a rate enhancement for the hydroformylation of 1-hexene. The tri-o-amino phosphine rhodium complex could be recycled to a certain extent by setting proper pH value after reaction.3. The aqueous phosphine ligands were found to be of typical surfactants and micelle effects. A higher activity along with a higher selectivity to normal aldehyde was achieved with a proper L/Rh ratio. No significant losses in the catalystic performances were observed for several consecutive runs with the catalyst generated from the better hydrophilic phosphine.4. It was found that the aqueous phosphine-rhodium complexes showed higher activity of 1-hexen hydroformylation in the media of hydrophilic ionic liquid coupled with suitable reaction conditions. The catalyst could be readily reused for several times through the phase separation after the reaction.5. The rhodium complexes generated from terr-butyl group(s) substituted triphenylphosphines showed cone angle effect for normal aldehyde in homogeneous system. Such Rh-P complexes could be uniformly and highly dispersed at the surfaces of amino-functionalized mesoporous silicas due to the chemical interaction between the surface amino-groups and the Rh-P complexes. Besides the good stability, the heterogenized catalysts afforded the catalytic activity and cone angle effect comparable to those of the corresponding homogeneous ones.