Phosphorus-31 nuclear magnetic resonance studies of polymer-anchored rhodium(I) complexes

Immobilization Techniques

“…The phosphine functionality can be introduced to polystyrenes by alternative approaches, such as lithiation (e.g., with butyllithium) followed by a reaction with ClP(C 6 H 5 ) 2 . For example, six different supported Rh-phosphine complexes were identified using NMR spectroscopy in the reaction of phosphinated polystyrene with an Rh-precursor [94]. It was found that the distribution of relatively bulky phosphine groups in the resin was strongly affected by the degree of cross-linking.…”

Synthesis and structure of metal complexes with organic polymers or inorganic supports

“…33). The possible and predictable formation of different organometallic species during the supportation on inorganic matrix has been clearly evidenced in the case of alumina/Cp*TiC13 (Cp* = pentamethylcyclopentadienyl) or alumina/CpTiClj systems (Ref.…”

Polymer-Bound Phosphine Catalysts

“…Examples of phosphinated monomers include vinyldiphenylphosphine, allyldiphenylphosphine, and p-diphenylphosphinostyrene; these are copolymerized with styrene (and sometimes divinylbenzene). (28)(29)(30)(31)(32)(33)(34) By varying the amounts of monomers a wide range of ligand loadings and cross-linking densities are possible.…”

“…There are just two major contributions in this area. (34,46) Both examined polymers prepared through the polymerization of phosphine monomers; this avoided the complicating effect of an uneven distribution of phosphine sites. These studies examined both cross-linked and noncross-linked polymers.…”

“…(34) Even with a phosphine function in each repeating unit, up to 200,000 pulses were required. The initial spectrum was different from the final one, apparently reflecting a 0.5-1 hr requirement for ligand exchange to reach equilibrium.…”