title: Ca(2+) -Induced Oxygen Generation by FeO4(2-) at pH 9-10.
abstract: Although FeO4(2-) (ferrate(IV)) is a very strong oxidant that readily oxidizes water in acidic medium, at pH 9-10 it is relatively stable (<2 % decomposition after 1 h at 298 K). However, FeO4(2-) is readily activated by Ca(2+) at pH 9-10 to generate O2. The reaction has the following rate law: d[O2]/dt=kCa [Ca(2+) ][FeO4(2-)](2). (18)O-labeling experiments show that both O atoms in O2 come from FeO4(2-). These results together with DFT calculations suggest that the function of Ca(2+) is to facilitate O-O coupling between two FeO4 (2-) ions by bridging them together. Similar activating effects are also observed with Mg(2+) and Sr(2+).
authors.affiliation: Department of Biology and Chemistry and Institute of Molecular Functional Materials, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong, China.
authors.forename: Li
authors.initials: L
authors.lastname: Ma
authors.affiliation: Department of Biology and Chemistry and Institute of Molecular Functional Materials, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong, China.
authors.forename: William W Y
authors.initials: WW
authors.lastname: Lam
authors.affiliation: Department of Biology and Chemistry and Institute of Molecular Functional Materials, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong, China.
authors.forename: Po-Kam
authors.initials: PK
authors.lastname: Lo
authors.affiliation: Department of Biology and Chemistry and Institute of Molecular Functional Materials, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong, China. kaichung@cityu.edu.hk.
authors.forename: Kai-Chung
authors.initials: KC
authors.lastname: Lau
authors.affiliation: Department of Biology and Chemistry and Institute of Molecular Functional Materials, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong, China. bhtclau@cityu.edu.hk.
authors.forename: Tai-Chu
authors.initials: TC
authors.lastname: Lau
keywords: Lewis acid; calcium; dioxygen generation; iron(VI)