title: Ultrafast Photoinduced Electron Transfer from Peroxide Dianion.
abstract: The encapsulation of peroxide dianion by hexacarboxamide cryptand provides a platform for the study of electron transfer of isolated peroxide anion. Photoinitiated electron transfer (ET) between freely diffusing Ru(bpy)3(2+) and the peroxide dianion occurs with a rate constant of 2.0 × 10(10) M(-1) s(-1). A competing electron transfer quenching pathway is observed within an ion pair. Picosecond transient spectroscopy furnishes a rate constant of 1.1 × 10(10) s(-1) for this first-order process. A driving force dependence for the ET rate within the ion pair using a series of Ru(bpy)3(2+) derivatives allows for the electronic coupling and reorganization energies to be assessed. The ET reaction is nonadiabatic and dominated by a large inner-sphere reorganization energy, in accordance with that expected for the change in bond distance accompanying the conversion of peroxide dianion to superoxide anion.
authors: †Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138-2902, United States.
authors: Bryce L
authors: BL
authors: Anderson
authors: †Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138-2902, United States.|‡Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States.
authors: Andrew G
authors: AG
authors: Maher
authors: ‡Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States.
authors: Matthew
authors: M
authors: Nava
authors: ‡Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States.
authors: Nazario
authors: N
authors: Lopez
authors: ‡Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139-4307, United States.
authors: Christopher C
authors: CC
authors: Cummins
authors: †Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138-2902, United States.
authors: Daniel G
authors: DG
authors: Nocera
mesh_terms: D000838:Anions / Q000737:chemistry; D004579:Electron Transport; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry; D010545:Peroxides / Q000737:chemistry*; D055668:Photochemical Processes; D011789:Quantum Theory
chemical_list: D000838:Anions; D009942:Organometallic Compounds; D010545:Peroxides; C415768:tris(2,2'-bipyridyl)ruthenium(II)