title: Reversible reduction of oxygen to peroxide facilitated by molecular recognition.
abstract: Generation of soluble sources of peroxide dianion (O(2)(2-)) is a challenge in dioxygen chemistry. The oxidizing nature of this anion renders its stabilization in organic media difficult. This Report describes the chemically reversible reduction of oxygen (O(2)) to cryptand-encapsulated O(2)(2-). The dianion is stabilized by strong hydrogen bonds to N-H groups from the hexacarboxamide cryptand. Analogous stabilization of peroxide by hydrogen bonding has been invoked recently in crystalline saccharide and protein systems. The present peroxide adducts are stable at room temperature in dimethyl sulfoxide (DMSO) and N,N'-dimethylformamide (DMF). These adducts can be obtained in gram quantities from the cryptand-driven disproportionation reaction of potassium superoxide (KO(2)) at room temperature.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA.
authors.forename: Nazario
authors.initials: N
authors.lastname: Lopez
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Graham
authors.forename: Robert
authors.initials: R
authors.lastname: McGuire
authors.forename: Glen E
authors.initials: GE
authors.lastname: Alliger
authors.forename: Yang
authors.initials: Y
authors.lastname: Shao-Horn
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Cummins
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Nocera