title: Catching an entatic state--a pair of copper complexes.
abstract: The structures of two types of guanidine-quinoline copper complexes have been investigated by single-crystal X-ray crystallography, K-edge X-ray absorption spectroscopy (XAS), resonance Raman and UV/Vis spectroscopy, cyclic voltammetry, and density functional theory (DFT). Independent of the oxidation state, the two structures, which are virtually identical for solids and complexes in solution, resemble each other strongly and are connected by a reversible electron transfer at 0.33 V. By resonant excitation of the two entatic copper complexes, the transition state of the electron transfer is accessible through vibrational modes, which are coupled to metal-ligand charge transfer (MLCT) and ligand-metal charge transfer (LMCT) states.
authors.affiliation: Ludwig-Maximilians-Universität München, Department Chemie, 81377 München (Germany).
authors.forename: Alexander
authors.initials: A
authors.lastname: Hoffmann
authors.forename: Stephan
authors.initials: S
authors.lastname: Binder
authors.forename: Anton
authors.initials: A
authors.lastname: Jesser
authors.forename: Roxana
authors.initials: R
authors.lastname: Haase
authors.forename: Ulrich
authors.initials: U
authors.lastname: Flörke
authors.forename: Manuel
authors.initials: M
authors.lastname: Gnida
authors.forename: Marco
authors.initials: M
authors.lastname: Salomone Stagni
authors.forename: Wolfram
authors.initials: W
authors.lastname: Meyer-Klaucke
authors.forename: Benjamin
authors.initials: B
authors.lastname: Lebsanft
authors.forename: Lara Elena
authors.initials: LE
authors.lastname: Grünig
authors.forename: Simon
authors.initials: S
authors.lastname: Schneider
authors.forename: Maryam
authors.initials: M
authors.lastname: Hashemi
authors.forename: Arne
authors.initials: A
authors.lastname: Goos
authors.forename: Alina
authors.initials: A
authors.lastname: Wetzel
authors.forename: Michael
authors.initials: M
authors.lastname: Rübhausen
authors.forename: Sonja
authors.initials: S
authors.lastname: Herres-Pawlis
mesh_terms: D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D015394:Molecular Structure; D010084:Oxidation-Reduction; D014961:X-Ray Diffraction
chemical_list: D003300:Copper
keywords: X-ray absorption spectrocopy; X-ray diffraction; bioinorganic chemistry; copper; resonance Raman spectroscopy