Abstract Details
| Multi-Edge X-ray Absorption Spectroscopy: A Powerful Probe into the Electronic Structure | |
|---|---|
| Abstract ID | LCLS/SSRL-13 |
| Presenter | Robert Szilagyi |
| Presentation Type | LCLS/SSRL Invited Speaker |
| Full Author List | R. K. Szilagyi (1) |
| Affiliations | (1) Dept. Chemistry and Biochemistry, Montana State Univ., Bozeman, MT |
| Category | Bio/Life Sciences |
| Abstract | Demonstrative examples will be discussed for the rich information content of the multi-edge X-ray absorption spectroscopic (meXAS) technique for classical and non-innocent inorganic complexes and organometallic compounds with catalytic importance. In particularly our recent meXAS results for the formally Cu(I)Cu(I)/Cu(I)Cu(II)/Cu(II)Cu(II) binuclear [1] redox system supported with pincer-type ligands will be presented. The electronic structures of these complexes show striking resemblance of the binuclear CuA active site of cytochrome c oxidase despite a very different Cu coordination environment. We also investigated the non-innocent behavior of the pincer type ligand in mononuclear complexes that was originally thought to be innocent ancillaries for a Ni(II)/Ni(III) systems [2]. The latter complexes show organometallic reactivity in C−X bond breaking events (where X = H, C, O, N, and the halides), specifically cross-coupling and functionalization reactions.
The above scientific insights could have not been gained without the nationally unparallel facilities of Stanford Synchrotron Radiation Laboratory, such as beamlines 7-3/9-3, 10-1/8-2, and 6-2/4-3 for hard, intermediate, and soft X-ray measurements, respectively. Access to these beamlines allowed us to determine the composition of chemically important, unoccupied frontier orbitals from both the metal and the ligand points of view, and thus allowed for an unambiguous mapping of the total electronic structure solely from experiment. We anticipate that the demand for these beamlines will grow in the future due to the unique information content of the meXAS technique. Development work at SSRL toward making these beamlines more accessible and user friendly will enable the expansion of the user base at SSRL toward more traditional organometallic chemists. |
| Footnotes | References:
1. Harkins, S.B.; Mankad, N.P; Miller, A.J.M.; Szilagyi, R.K; Peters, J.C. Probing the Electronic Structures of [Cu2(m-XR2)]n+ Diamond Cores as a Function of the Bridging X Atom (X = N or P) and Charge (n = 0, 1, 2) J. Am. Chem. Soc. 2008, 130(11), 3478-3485 2. Adhikari, D.; Mossin, S.; Basuli, F.; Huffman, J.C.; Szilagyi, R.K.; Meyer, K.; Mindiola, D.J. Structural, Spectroscopic, and Theoretical Elucidation of a Redox-Active Pincer-Type Ancillary Applied in Catalysis J. Am. Chem. Soc. 2008, 130(11), 3676-3682 |
| Funding Acknowledgement | |