Dalton communications. Effects of catalyst site accessibility on catalysis by rhodium(I) complexes of amphiphilic ligands [Ph2P(CH2)nPMe3]+(n= 2, 3, 6 or 10) tethered to a cation-exchange resin

Abstract

The effects of catalyst site accessibility on the activities of supported olefin hydrogenation catalysts have been assessed utilizing the complexes [Rh(nbd)L₂][NO₃]₃[nbd =η⁴-norbornadiene; L = Ph₂P(CH₂)_nPMe₃⁺; n= 2, 3, 6 or 10] tethered to a cation-exchange resin via the tetraalkyl-phosphonium moieties of the co-ordinated ligands; the most active catalysts are those containing the longer-chain ligands, where the catalyst sites are farthest removed from steric hindrance by the resin surface.