X-ray Absorption Edge Spectroscopy and Computational Studies on LCuO Species: Superoxide—Cu versus Peroxide—Cu Bonding.
The geometric and electronic structures of two mononuclear CuO complexes, [Cu(O){HB(3-Ad-5-Prpz)}] (1) and [Cu(O)(β-diketiminate)] (2), have been evaluated using Cu K- and L-edge X-ray absorption spectroscopy (XAS) studies in combination with valence bond configuration interaction (VBCI) simulations...
| Publicado en: | Journal of the American Chemical Society Vol. 128; no. 25; pp. 8286 - 8297 |
|---|---|
| Autores principales: | , , , , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
6/28/2006
|
| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=hlh&AN=21506973&site=ehost-live header: @attributes: shortDbName: hlh uiTerm: 21506973 longDbName: Humanities International Complete uiTag: AN controlInfo: bkinfo: jinfo: jid: 00027863 ACS jtl: Journal of the American Chemical Society issn: 00027863 maglogo: N pubinfo: dt: 6/28/2006 vid: 128 iid: 25 pid: 997 pub: American Chemical Society artinfo: ui: 21506973 10.1021/ja0615223 ppf: 8286 ppct: 11 formats: tig: atl: X-ray Absorption Edge Spectroscopy and Computational Studies on LCuO Species: Superoxide—Cu versus Peroxide—Cu Bonding. aug: au: Sarangi, Ritimukta Aboelella, Nermeen Fujisawa, Kiyoshi Tolman, William B. Hedman, Britt Hodgson, Keith O. Solomon, Edward I. affil: Department of Chemistry, Stanford University, Stanford, California 94305 Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, Minnesota 55108 Department of Chemistry, University of Tsukuba, Tsukuba 305-8571, Japan Stanford Synchrotron Radiation Laboratory, Stanford Linear Accelerator Center, Stanford University, Stanford, California 94309 su: Spectrum analysis Chemical bonds Density functionals Functional analysis Synchrotron radiation Electromagnetic waves sug: subj: Spectrum analysis Chemical bonds Density functionals Functional analysis Synchrotron radiation Electromagnetic waves ab: The geometric and electronic structures of two mononuclear CuO complexes, [Cu(O){HB(3-Ad-5-Prpz)}] (1) and [Cu(O)(β-diketiminate)] (2), have been evaluated using Cu K- and L-edge X-ray absorption spectroscopy (XAS) studies in combination with valence bond configuration interaction (VBCI) simulations and spin-unrestricted broken symmetry density functional theory (DFT) calculations. Cu K- and L-edge XAS data indicate the Cu(II) and Cu(III) nature of 1 and 2, respectively. The total integrated intensity under the L-edges shows that the ψ*'s in 1 and 2 contain 20% and 28% Cu character, respectively, indicative of very covalent ground states in both complexes, although more so in 1. Two-state VBCI simulations also indicate that the ground state in 2 has more Cu (∣3d)) character. DFT calculations show that the ψ* in both complexes is dominated by O character, although the O character is higher in 1. It is shown that the ligand L plays an important role in modulating CuO bonding in these LCuO systems and tunes the ground states of 1 and 2 to have dominant Cu(II)-superoxide-like and Cu(III)-peroxide-like character, respectively. The contributions of ligand field (LF) and the charge on the absorbing atom in the molecule (Q) to L- and K-edge energy shifts are evaluated using DFT and time-dependent DFT calculations. It is found that LF makes a dominant contribution to the edge energy shift, while the effect of Q is minor. The charge on the Cu in the Cu(III) complex is found to be similar to that in Cu(II) complexes, which indicates a much stronger interaction with the ligand, leading to extensive charge transfer. pubtype: Academic Journal doctype: Article src: R language: English refInfo: copyright: @attributes: flag: Y dt: @attributes: year: 2006 holdings: @attributes: islocal: N |
|---|