title: Spectroscopic and computational studies of an end-on bound superoxo-Cu(II) complex: geometric and electronic factors that determine the ground state.
abstract: A variety of techniques including absorption, magnetic circular dichroism (MCD), variable-temperature, variable-field MCD (VTVH-MCD), and resonance Raman (rR) spectroscopies are combined with density functional theory (DFT) calculations to elucidate the electronic structure of the end-on (η(1)) bound superoxo-Cu(II) complex [TMG(3)trenCuO(2)](+) (where TMG(3)tren is 1,1,1-tris[2-[N(2)-(1,1,3,3-tetramethylguanidino)]ethyl]amine). The spectral features of [TMG(3)trenCuO(2)](+) are assigned, including the first definitive assignment of a superoxo intraligand transition in a metal-superoxo complex, and a detailed description of end-on superoxo-Cu(II) bonding is developed. The lack of overlap between the two magnetic orbitals of [TMG(3)trenCuO(2)](+) eliminates antiferromagnetic coupling between the copper(II) and the superoxide, while the significant superoxo π*(σ) character of the copper dz(2) orbital leads to its ferromagnetically coupled, triplet, ground state.
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305, USA.
authors.forename: Julia S
authors.initials: JS
authors.lastname: Woertink
authors.forename: Li
authors.initials: L
authors.lastname: Tian
authors.forename: Debabrata
authors.initials: D
authors.lastname: Maiti
authors.forename: Heather R
authors.initials: HR
authors.lastname: Lucas
authors.forename: Richard A
authors.initials: RA
authors.lastname: Himes
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Karlin
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.forename: Christian
authors.initials: C
authors.lastname: Würtele
authors.forename: Max C
authors.initials: MC
authors.lastname: Holthausen
authors.forename: Eckhard
authors.initials: E
authors.lastname: Bill
authors.forename: Jörg
authors.initials: J
authors.lastname: Sundermeyer
authors.forename: Siegfried
authors.initials: S
authors.lastname: Schindler
authors.forename: Edward I
authors.initials: EI
authors.lastname: Solomon
mesh_terms: D000042:Absorption; D003300:Copper / Q000737:chemistry*; D004579:Electron Transport; D004583:Electrons; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013057:Spectrum Analysis
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D003300:Copper