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6644822 
Journal Article 
THE STRUCTURE OF IRON(III) TETRA(4-N-METHYLPYRIDYL)PROPHYRIN SPECIES BOUND TO SYNTHETIC WATER-SOLUBLE ANIONIC POLYMERS AND THEIR REACTIONS WITH TERT-BUTYL HYDROPEROXIDE IN AQUEOUS-SOLUTION 
Smith, JRL; Lower, RJ; , 
1992 
ROYAL SOC CHEMISTRY 
CAMBRIDGE 
2187-2196 
WOS:A1992KB89200016 
This paper describes studies carried out to investigate the nature of the species that are formed when the cationic iron(III) tetra(4-N-methylpyridyl)porphyrin (FeIIIT4MPyP) is bound to three water-soluble anionic polymers, namely, poly(styrene-4-sulfonate), poly(vinylsulfonate) and poly-(acrylate), in water at pH 9.2. GPC studies with FeIIIT4MPyP and its free base, H2T4MPyP, show that the iron porphyrin is bound by electrostatic interactions and by ligation to the metal. UV-VIS spectroscopy reveals that the polymers induce a broadening and a blue-shift of the metalloporphyrin Soret band and for poly(styrene-4-sulfonate) the extent to which this occurs depends on the method of preparation of the polymer-bound porphyrin. Resonance Raman spectroscopy shows that with poly(styrene-4-sulfonate) the iron porphyrin is bound as a low spin iron species whilst with poly(acrylate) it is a mixture of high and low spin species.The rates of reactions of polymer-bound FeIIIT4MPyP with imidazole and with ButO2H in the presence of 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) are found to be dependent on the nature of the polymer and, for poly(styrene-4-sulfonate), on the method of preparation of the bound catalyst. Products from the polymer-FeIIIT4MPyP-catalysed decomposition of tert-butyl hydroperoxide in the presence and absence of ABTS have been determined and the oxidant accountability is excellent. Evidence for the formation of polymer-bound oxoiron(IV) tetra(4-N-methylpyridyl) porphyrin in the reactions with ButO2H is presented.Possible structures for the polymer-bound FeIIIT4MPyP are discussed and it is concluded that the metalloporphyrin is extensively aggregated on the polymer chains as mu-oxo x-mers.