Bleach catalysis in aqueous medium by iron(III)-isoindoline complexes and hydrogen peroxide

Hydrogen peroxide and peroxymonocarbonate anion-based bleach reactions are important for many applications such as paper bleach, waste water treatment laundry. Nonheme iron(III) complexes, [Fe III (L 1-4 )Cl 2 ] with the 1,3-bis(2 ′ -Ar-imino)isoindolines ligands (HL n , n=1–4, Ar = pyridyl, thiazolyl, benzimidazolyl N-methylbenzimidazolyl, respectively) have been shown to catalyze oxidative degradation of morin a soluble model bleachable stain by H O in buffered aqueous solution. In these experiments bleaching activity catalysts was significantly influenced Lewis acidity redox properties metal centers, showed linear correlation Fe /Fe II potentials (in range 197–415 mV) controlled modification electron donor ligand introducing various aryl groups on bis-iminoisoindoline moiety. A similar trend but low yields observed disproportionation (catalase-like reaction) which is major side reaction catalytic transition complexes. The effect bicarbonate ions might be explained reduction Fe(III) and/or formation monoanion, much stronger oxidant could increase catalytically active high-valent oxoiron species.