Characterization and hydroformylation performance of mesoporous MCM-41-supported water-soluble Rh complex dissolved in ionic liquids

The TPPTS-Rh complex [TPPTS = trisodium salt of tri-(m-sulfophenyl)-phosphine, P(m-C6H4SO3Na)3], which was dissolved in the ionic liquids 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMI⋅BF4), 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMI⋅PF6), and 1,1,3,3-tetramethylguanidinium lactate (TMGL), was immobilized on MCM-41. The resulting supported ionic liquid-phase catalysts (SILPCs) were very active for the hydroformylation of higher olefins. The SILPCs with the regular hexagonal array of MCM-41 were structurally stable before and after the catalytic reaction, as characterized by XRD, N2 adsorption/desorption, FTIR, 31P-NMR, SEM, HRTEM, and TGA-DSC. The obtained SILPCs showed higher catalytic activity, independent of IL type, as compared with their ionic liquid-organic biphasic counterparts and the one with SiO2 as carrier. Such SILPCs could be reused several times without significant loss of activity or selectivity.