title: Formation of hybrid guanidine-stabilized bis(μ-oxo)dicopper cores in solution: Electronic and steric perturbations.
abstract: A series of new hybrid peralkylated-amine-guanidine ligands based on a 1,3-propanediamine backbone and their Cu-O2chemistry is reported. The copper(I) complexes react readily with O2at low temperatures in aprotic solvents with weakly coordinating anions to form exclusively bis(μ-oxo) dicopper species (O). Variation of the substituents on each side of the hybrid bidentate ligand highlights that less sterically demanding amine and guanidine substituents increase not only the thermal stability of the formedOcores but enhance inner-sphere phenolate hydroxylation pathways. TD-DFT analysis on selected guanidine-amineOspecies suggest that the additional visible feature observed is a guanidine π*→ Cu2O2LMCT, which appears along with the classic oxo-ζu*→Cu(III) and πζ*→ Cu(III) LMCT transitions.
authors.affiliation: Lehrstuhl für Bioanorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Sonja
authors.initials: S
authors.lastname: Herres-Pawlis
authors.affiliation: Department Chemie, Anorganische Chemie, Universität Paderborn, 33098 Paderborn, Germany.
authors.forename: Roxana
authors.initials: R
authors.lastname: Haase
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305.
authors.forename: Pratik
authors.initials: P
authors.lastname: Verma
authors.affiliation: Lehrstuhl für Bioanorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Hoffmann
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305.
authors.forename: Peng
authors.initials: P
authors.lastname: Kang
authors.affiliation: Department of Chemistry, Stanford University, Stanford, California 94305.
authors.forename: T Daniel P
authors.initials: TD
authors.lastname: Stack
keywords: Copper; Density Functional Theory; Dioxygen; Guanidine Ligands; UV/Vis-Spectroscopy