title: Tuning of the [Cu3(mu-O)]4+/5+ redox couple: spectroscopic evidence of charge delocalization in the mixed-valent [Cu3(mu-O)]5+ species.
abstract: Trinuclear Cu (II)-complexes of formula [Cu (II) 3(mu 3-E)(mu-4-R-pz) 3X 3] (+/- n ), E = O and OH; R = H, Cl, Br, CH(O) and NO 2; X = Cl, NCS, CH 3COO, and py, have been synthesized and characterized and the effect of substitution of terminal ligands, as well as 4-R-groups, in the one-electron oxidation process has been investigated by cyclic voltammetry. In situ UV-vis-NIR spectroelectrochemical characterization of the mixed valence Cu 3 (7+)-complex [Cu 3(mu 3-O)(mu-pz) 3Cl 3] (-) revealed an intervalence charge transfer band at 9550 cm (-1) (epsilon = 2600 cm (-1) M (-1)), whose analysis identifies this species as a delocalized, Robin-Day class-III system, with an electronic coupling factor, H ab, of 4775 cm (-1).
authors.affiliation: Department of Chemistry, University of Puerto Rico, P.O. Box 23346, San Juan, Puerto Rico.
authors.forename: Marlyn
authors.initials: M
authors.lastname: Rivera-Carrillo
authors.forename: Indranil
authors.initials: I
authors.lastname: Chakraborty
authors.forename: Gellert
authors.initials: G
authors.lastname: Mezei
authors.forename: Richard D
authors.initials: RD
authors.lastname: Webster
authors.forename: Raphael G
authors.initials: RG
authors.lastname: Raptis
mesh_terms: D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010084:Oxidation-Reduction; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009942:Organometallic Compounds; D003300:Copper