Dear Sin-Yuen, Your Au(I)Cl seems to be significantly oxidized to HAu(III)Cl4, as can be judged by the pronounced pre-edge feature at ~11921 eV, typical of square-coordinated Au(III) compounds. I added a few (likely good!) spectra of Au(III) and Au(I) chloride reference compounds to your athena file (attached), together with the paper in which they were published. My AuCl(s) looks much less oxidized than yours, but still might be somewhat altered; the best Au(I)Cl2 reference, to my opinion, is the aqueous AuCl2(-) complex, which is stable in acidic Cl solutions at elevated temperatures (included in the file). Please feel free to use these spectra by referring to this paper. best regards Gleb Dr. Gleb S. Pokrovski Directeur de Recherche CNRS Associate Editor of Economic Geology Associate Editor of Geochimica et Cosmochimica Acta Geosciences Environnement Toulouse (ex-LMTG) GET - UMR 5563 of CNRS, University of Toulouse III 14 avenue Edouard Belin , F- 31400 TOULOUSE, France e-mail:gleb.pokrovski@get.obs-mip.fr;glebounet@gmail.com phone: 33-5-61-33-26-18 , fax: 33-5-61-33-25-60 On 27/06/2014 20:11, Sin Yuen Chang wrote:
Many thanks for the response, Bruce.
For something as tricky as Au(1+) chloride, I think it is unwise to blindly trust data that you found in some disreputable corner of the internet. It really seems like the kind of thing you need to measure for yourself if you want confidence in what you have. Exactly what I am working on!
Best regards, Sin-Yuen
-----Original Message----- From:ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Bruce Ravel Sent: 27 June 2014 16:40 To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] Solid AuCl EXAFS fitting – big N
On 06/27/2014 01:14 AM, Sin Yuen Chang wrote:
Given how many times AuCl XANES has been published before, has anyone else perhaps run into this problem? Has anyone perhaps measured solid AuCl under exclusion of moisture and air, or several times as a function of time to assess beam damage?
I was under the impression that *everyone* runs into that problem. As you say Au(1+) chloride is quite unstable. Given that the white line in the data that you took from my LCF fitting example is so close in size to that of Au(3+) chloride, I would guess that the sample was no pure Au(1+) by the time we measured it.
For something as tricky as Au(1+) chloride, I think it is unwise to blindly trust data that you found in some disreputable corner of the internet. It really seems like the kind of thing you need to measure for yourself if you want confidence in what you have.
B
-- Bruce Ravel ------------------------------------bravel@bnl.gov
National Institute of Standards and Technology Synchrotron Science Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973
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