title: Manganese Kβ X-ray emission spectroscopy as a probe of metal-ligand interactions.
abstract: A systematic series of high-spin mononuclear Mn(II), Mn(III), and Mn(IV) complexes has been investigated by manganese Kβ X-ray emission spectroscopy (XES). The factors contributing to the Kβ main line and the valence to core region are discussed. The Kβ main lines are dominated by 3p-3d exchange correlation (spin state) effects, shifting to lower energy upon oxidation of Mn(II) to Mn(III) due to the decrease in spin state from S = 5/2 to S = 2, whereas the valence to core region shows greater sensitivity to the chemical environment surrounding the Mn center. A density functional theory (DFT) approach has been used to calculate the valence to core spectra and assess the contributions to the energies and intensities. The valence spectra are dominated by manganese np to 1s electric dipole-allowed transitions and are particularly sensitive to spin state and ligand identity (reflected primarily in the transition energies) as well as oxidation state and metal-ligand bond lengths (reflected primarily in the transition intensities). The ability to use these methods to distinguish different ligand contributions within a heteroleptic coordination sphere is highlighted. The similarities and differences between the current Mn XES study and previous studies of Fe XES investigations are discussed. These findings serve as an important calibration for future applications to manganese active sites in biological and chemical catalysis.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA.
authors.forename: Martha A
authors.initials: MA
authors.lastname: Beckwith
authors.forename: Michael
authors.initials: M
authors.lastname: Roemelt
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Collomb
authors.forename: Carole
authors.initials: C
authors.lastname: DuBoc
authors.forename: Tsu-Chien
authors.initials: TC
authors.lastname: Weng
authors.forename: Uwe
authors.initials: U
authors.lastname: Bergmann
authors.forename: Pieter
authors.initials: P
authors.lastname: Glatzel
authors.forename: Frank
authors.initials: F
authors.lastname: Neese
authors.forename: Serena
authors.initials: S
authors.lastname: DeBeer
mesh_terms: D008024:Ligands; D008345:Manganese / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D011789:Quantum Theory; D013052:Spectrometry, X-Ray Emission; D013237:Stereoisomerism
chemical_list: D008024:Ligands; D009942:Organometallic Compounds; D008345:Manganese