Polymer supported metal catalysts heterogenous catalyst

Although the oxidation of tertiary phosphines by these catalytic processes has minimal useful application, it needs to be considered as a problematic side reaction in homogeneous catalysis. Much effort is being currently expended to immobilize platinum metal phosphine complexes on heterogenized tertiary phosphine supports, and irreversible oxidation at phosphorus on these supports effectively destroys the supported catalyst. Recent observations that the compound Rh6(CO)i6 catalyzes the oxidation of tertiary phosphines correlate with the report that phosphine oxidation occurs with molecular oxygen on Rh6(CO)i6 bound to diphenylphosphino-functionalized poly(styrenedivinylbenzene). Thus, in order to use these phosphinated polymer-supported rhodium catalysts, one needs either to rigorously exclude oxygen, or to find a way to inhibit the simultaneous catalyzed phosphine oxidation. 

Chandrasekhar, V. and Athimoolam, A. (2002) New hybrid inorganic-organic polymers as supports for heterogeneous catalysis a novel Pd(0) metalated cyclophosphazene-containing polymer as an efficient heterogeneous catalyst for the Heck reaction. Org. Lett., 4, 2113-6. 

From the discussion in the previous sections, it is apparent that whatever the morphology of the CFP, macroreticular or gel-type, the metal nanoclusters in polymer-supported heterogeneous metal catalysts are... 

---