On the redox reactions of radicals with AlIII(phthalocyaninate) pendants covalently bonded to poly(ethyleneamide). Mechanistic alterations when radicals are formed inside pockets of micelle-like polymer aggregates

The mechanisms of the redox reactions between a polymer containing Al(III) sulfonated phthalocyanine pendants, (AlIII(⌊NHS(O2)trspc)2−)2, and radicals have been investigated in this work. Pulse radiolysis and photochemical methods were used for these studies. Oxidizing radicals, OH•, HCO3•, (CH3)2COHCH2•, and N3•, as well as reducing radicals, eaq−, CO2•−, and (CH3)2C•OH, respectively accept or donate one electron forming pendent phthalocyanine radicals, AlIII(⌊NHS(O2)trspc •)− or 3−. The kinetics of the redox processes is consistent with a mechanism where the pendants react with radicals formed inside aggregates of five to six polymer strands. Electron donating radicals, that is, CO2•− and (CH3)2C•OH, produce one‐electron reduced phthalocyanine pendants that, even though they were stable under anaerobic conditions, donated charge to a Pt catalyst. While the polymer was regenerated in the Pt catalyzed processes, 2‐propanol and CO2 were respectively reduced to propane and CO. The reaction of SO3•− radicals with the polymer stood in contrast with the reactions of the radicals mentioned above. A first step of the mechanism, the coordination of the SO3•− radical to the Al(III), was subsequently followed by the formation of a SO3•−‐phthalocyanine ligand adduct. The decay of the SO3•−‐phthalocyanine ligand adduct in a ∼102 ms time domain regenerates the polymer, and it was attributed to the dimerization/disproportionation of SO3•− radicals escaping from the aggregates of polymer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 Aggregates of ∼ 5 strands are formed in aqueous solutions of Al(III) phthalocyanine‐decorated poly(ethyleneamide). Redox processes of organic and inorganic radicals inside the aggregates exhibit distinct reaction mechanisms.