Iron(III) Oxidation of Carboxylic Acids and Phenols as Models for the Abiotic Transformation of Natural Organic Matter William D. Kerber, Bucknell University, Department of Chemistry, Lewisburg, PA 17837 OH
N
X FeIII O N
N N
N N FeIII X
X k1 N
k-1
O
O
(TPA) FeIII O FeIII(TPA)
O
OH
HO
X k2
(TPA) FeIII O FeII(TPA) H
2 [FeIITPA]+2(aq)
N
1a: X = H2O 1b: X = H2O, OH1c: X = OH-
Models of dimeric iron(III) complexes found in natural organic matter (NOM) have been shown to oxidize hydroquinone, a common functional group in NOM. The reaction kinetics support a pre-equilibrium mechanism in which rapid formation of an iron(III)phenoxide complex is followed by rate limiting innersphere electron transfer.
1a
1c
1b
