FUNCTIONAL METALLOMACROCYCLES AND THEIR POLYMERS .34. KINETICS AND MECHANISM OF THE BIOMIMETIC DECOMPOSITION OF HYDROGEN-PEROXIDE CATALYZEDBY HETEROGENEOUS OCTACARBOXYPHTHALOCYANINATO IRON(III) SUPPORTED ON AMORPHOUS ENRICHED RAYON STAPLE FIBERS

Catalase-like decomposition of hydrogen peroxide with the octacarboxy- phthalocyaninatoiron(III) (Fe(III)-oapc) supported on amorphous enrich ed rayon staple fibre (degree of crystallinity = 14%) was studied in a queous solution at pH 7.0 and 25 degrees C. The Fe(III)-oapc supported on the rayon staple fibre is remarkably effective as an immobilized c atalyst for decomposition of hydrogen peroxide. The reaction rate was analysed in terms of Michaelis-Menten kinetics, which suggests that th e catalysed decomposition of hydrogen peroxide proceeds via the format ion of an activated complex. Iron atom distribution of the rayon stapl e fibre indicated that Fe(III)-oapc existed on the fibre homogeneously . Electronic and e.s.r. spectra of the fibre suggests monomeric Fe(III )-oapc with a distorted rhombic coordinating high spin iron(III) ion. Fe(III)-oapc is considered to be immobilized by hydrogen bonding betwe en carboxylic groups on Fe(III)-oapc and hydroxy groups of cellulose, and a weak coordination bonding of iron with hydroxy groups on cellulo se. The immobilization of Fe-oapc to the rayon staple fibre extends it s catalytic lifetime and makes the catalyst molecule the monomeric act ive state. Copyright (C) 1996 Elsevier Science Ltd.