Spectroscopic Study of Electron Transfer in a Trifunctional Lysine with Anthraquinone as the Electron Acceptor

Journal Article (Journal Article)

The transient properties of the redox-active amino acid dyads [Anq-Lys(RuIIb2m)2+-OCH3](PF6)2 and [Boc-Lys(RuIIb2m)2+-NH-prPTZ](PF6)2 and the trifunctionalized amino acid [Anq-Lys(RuIIb2m)2+-NH-prPTZ](PF6)2, where Anq is 9,10-anthraquinone-2-carbonyl, Lys is l-lysine, b is 2,2′-bipyridine, m is 4′-methyl-2,2′-bipyridine-4-carbonyl, and prPTZ is 3-(10H-phenothiazine-10)propyl, were examined in CH3CN after nanosecond laser excitation. This series of redox-active assemblies was prepared by attaching derivatives of the ruthenium tris(bipyridyl) chromophore, the electron donor phenothiazine, and/or the electron acceptor anthraquinone to l-lysine with amide bonds. Emission from the chromophore was efficiently quenched (>95%) by the attached donors or acceptors in all three cases. Irradiation of [Anq-Lys(RuIIb2m)2+-NH-prPTZ] with 420-nm, 4-ns laser pulses resulted in net electron transfer from prPTZ to Anq, mediated by the metal-to-ligand charge-transfer (MLCT) excited state of the ruthenium chromophore, as observed by nanosecond transient absorption and time-resolved resonance Raman spectroscopies. The resulting redox-separated state, [(Anq•−)-Lys(RuIIb2m)2+-NH-(prPTZ•+)], at 1.54 eV, was formed with a quantum efficiency of 26% at its maximum appearance and persisted for 174 ns in CH3CN at 25 °C. © 1994, American Chemical Society. All rights reserved.

Full Text

Duke Authors

Cited Authors

  • Mecklenburg, SL; McCafferty, DG; Schoonover, JR; Peek, BM; Erickson, BW; Meyer, TJ

Published Date

  • June 1, 1994

Published In

Volume / Issue

  • 33 / 13

Start / End Page

  • 2974 - 2983

Electronic International Standard Serial Number (EISSN)

  • 1520-510X

International Standard Serial Number (ISSN)

  • 0020-1669

Digital Object Identifier (DOI)

  • 10.1021/ic00091a042

Citation Source

  • Scopus