On the observation of intervalence charge transfer bands in hydrogen-bonded mixed-valence complexes.
Ruthenium clusters of the type [Ru3(μ3-O)(OAc)6(CO)(L)(nic)], where L = 4-dimethylaminopyridine (dmap) and nic = isonicotinic acid, form hydrogen-bonded mixed-valence dimers upon a single electron reduction. Electrochemical responses show two overlapping reduction waves, indicating the presence of a thermodynamically stable mixed-valence dimer with considerable electronic coupling across the hydrogen bond. Electronic spectra of the singly reduced hydrogen-bonded mixed-valence dimer reveal two intervalence charge transfer bands in the near-infrared region consistent with a Robin-Day class II system. These bands are assigned as metal-to-metal and metal-to-bridge charge transfer, and their behavior is best described by a semiclassical three state model. Infrared spectroscopy suggests localized behavior indicating electron transfer between the two clusters is slower than 10(10) s(-1).
Department of Chemistry and Biochemistry, University of California San Diego , 9500 Gilman Dr. MC 0358, La Jolla, California 92093-0358, United States.
Gabriele
G
Canzi
John C
JC
Goeltz
Jane S
JS
Henderson
Roger E
RE
Park
Chiara
C
Maruggi
Clifford P
CP
Kubiak
D056831:Coordination Complexes / Q000737:chemistry*; D019281:Dimerization; D004563:Electrochemistry; D004579:Electron Transport; D006860:Hydrogen Bonding; D008956:Models, Chemical; D015394:Molecular Structure; D012428:Ruthenium / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics
D056831:Coordination Complexes; D012428:Ruthenium