- Tuesday, January 1, 1991
- Preparation and characterization of poly(siloxane)-supported tetra(-4-pyridyl)porphyrinatomanganese(III) catalysts for oxidation reactions
- Published at:Not Found
H. S. Hilal*, C.Kim, M.L.Sito and A.F.Schreiner, J. Mol. Catal. , 64(1991)133-142.
Tetra(4-pyridyl)porphyrinatomanganese(III), [MnIII(TPyP)]+, has been covalently bonded to the surface of a chlorinated crosslinked poly(siloxane) which contains the immobilized chloropropyl group, -CH-CH&H&l. The metalloporphyrin complex was found to react with the immobilized ligand via a quaternization reaction of the 4-pyridlne N-atom. The porphyrin binding involves a chemical process rather than physical adsorption. There is evidence that two porphyrins species coexist, both bonded to the surface, one being
quatemization reaction is carried out at higher temperature (150 “C). At moderate reaction temperatures (70-80 “C) the quatemization reaction resulted in only one species, supported [MnIII(TPyP)
demetallated[ MnIII(TPyP) ]+ and the other (H2TPyP), both in the quatemary salt forms, when the ]+ , as evident from electronic spectra of the solid. Also, visible absorption spectra taken of the solution remainin g after the quatemixation reaction showed no po rphyrin. Solid state electronic absorption, dispersive IR and FT-IR spectra have been used for confirmation.