ISSN:
1572-879X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Catalysts prepared by impregnation of the molecular species H(CO)Rh[P(C6H5)3]3 or ClRh[P(C6H5)3]3 with the aluminophosphate micropore VPI-5 have been found to catalyse the conversion of sodium 4-styrenesulfonate in aqueous solution in the presence of gaseous H2/CO mixture into the expected aldehyde hydroformylation product together with a substantial quantity of olefin polymer. Reaction in the presence of H2 in the gas phase gave the expected olefin hydrogenation product but no polymer, while in the presence of CO or N2 in the gas phase no reaction product of any sort could be found. The addition of a small quantity of hydroquinone as a radical scavenger to the reaction in the presence of gaseous H2/CO had no effect, indicating that the polymerization process did not occur by a free radical mechanism. It is suggested that polymerization occurs via a coordinated ligand insertion mechanism, and evidence suggests that the catalytic sites are those rhodium complex molecules which are externally accessible either at VPI-5 pore mouths or otherwise are located at the VPI-5 external surface, and which have been modified, probably by a ligand exchange process involving VPI-5 framework atoms.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1019092318145
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