title: X-ray emission spectroscopy to study ligand valence orbitals in Mn coordination complexes.
abstract: We discuss a spectroscopic method to determine the character of chemical bonding and for the identification of metal ligands in coordination and bioinorganic chemistry. It is based on the analysis of satellite lines in X-ray emission spectra that arise from transitions between valence orbitals and the metal ion 1s level (valence-to-core XES). The spectra, in connection with calculations based on density functional theory (DFT), provide information that is complementary to other spectroscopic techniques, in particular X-ray absorption (XANES and EXAFS). The spectral shape is sensitive to protonation of ligands and allows ligands, which differ only slightly in atomic number (e.g., C, N, O...), to be distinguished. A theoretical discussion of the main spectral features is presented in terms of molecular orbitals for a series of Mn model systems: [Mn(H(2)O)(6)](2+), [Mn(H(2)O)(5)OH](+), and [Mn(H(2)O)(5)NH(3)](2+). An application of the method, with comparison between theory and experiment, is presented for the solvated Mn(2+) ion in water and three Mn coordination complexes, namely [LMn(acac)N(3)]BPh(4), [LMn(B(2)O(3)Ph(2))(ClO(4))], and [LMn(acac)N]BPh(4), where L represents 1,4,7-trimethyl-1,4,7-triazacyclononane, acac stands for the 2,4-pentanedionate anion, and B(2)O(3)Ph(2) represents the 1,3-diphenyl-1,3-dibora-2-oxapropane-1,3-diolato dianion.
authors: Faculty of Physics and Research Center for Nanoscale Structure of Matter, Southern Federal University, 344090 Rostov-on-Don, Russia. smolentsev@yandex.ru
authors: Grigory
authors: G
authors: Smolentsev
authors: Alexander V
authors: AV
authors: Soldatov
authors: Johannes
authors: J
authors: Messinger
authors: Kathrin
authors: K
authors: Merz
authors: Thomas
authors: T
authors: Weyhermüller
authors: Uwe
authors: U
authors: Bergmann
authors: Yulia
authors: Y
authors: Pushkar
authors: Junko
authors: J
authors: Yano
authors: Vittal K
authors: VK
authors: Yachandra
authors: Pieter
authors: P
authors: Glatzel
mesh_terms: D008024:Ligands; D017895:Manganese Compounds / Q000737:chemistry*; D008958:Models, Molecular; D013052:Spectrometry, X-Ray Emission / Q000379:methods*
chemical_list: D008024:Ligands; D017895:Manganese Compounds