Re: [Ifeffit] How to identify N and O atoms in the first coordinate

Hello mzhu I mean edge of xanes, not pre-edge. I agree that the bonding length affects to the edge, so that you need to check the bonding length of the nitrogen-coordinated organic and others by using EXAFS. As you compare the results of EXAFS with the edge of xanes, you may check whether the shift of edge is made by the bonding length or nitrogen atom. I also think that the calculation of the shift of edge by using FEFF gives you help Have a nice day!

From: mzhu@udel.edu> To: ifeffit@millenia.cars.aps.anl.gov> Date: Sat, 20 Dec 2008 10:57:12 -0500> Subject: Re: [Ifeffit] How to identify N and O atoms in the first coordinate> > Hello JeongEunSuk,> Following your recommendation, I do find the pre-edge peak corresponding to s->d electron transition slightly shifts to higher energy for a nickel nitrogen-coordinated organic reference than for a nickel oxygen-coordinated organic reference. But the peak position is nearly the same for the nitrogen-coordinated organic reference with the aqueous nickel solution. I guess it is because the long Ni-OH2 bond in the aqueous nickel solution which also results in a less electron density on nickel(higher oxidation state). I will think about that. Thanks for your recommendations. > > Best wishes,> > Mengqiang Zhu > > > > > > > > -----------------------> Mengqiang Zhu> Ph.D Candidate > Environmental Soil Chemistry> Department of Plant and Soil Sciences > University of Delaware> 152 Townse! nd Hall> Newark, DE 19716 > http://ag.udel.edu/soilchem/zhu.html > > > ---- Original message ----> >Date: Sat, 20 Dec 2008 16:02:44 +0900> >From: ifeffit-bounces@millenia.cars.aps.anl.gov (on behalf of JeongEunSuk )> >Subject: Re: [Ifeffit] How to identify N and O atoms in the first coordinate > >To: ifeffit > >> > Hello mzhu> > > > I think that it is impossible to distinguish> > nitrogen with oxygen by using EXAFS. I would like> > to recommend XANES for your study.> > The shift of pre-edge of XANES shows how the> > oxidation state of metal is changed.> > As you know, If there are nitrogen atoms in> > substitute for oxygen atoms around metal, the> > pre-edge of metal xanes may shift to high energy> > because the oxidation state increases.> > > >> > > From: mzhu@udel.edu> > > To: ifeffit@millenia.cars.aps.anl.gov> > > Date: Fri, 19 Dec 2008 16:20:39 -0500> > > Subject: [Ifeffit] How to identify N and O atoms> > in th! e first coordinate> > >> > > Hello all,> > > Merry Christmas!> > > I h ave some samples of heavy metal sorption on> > bacterial biofilm. I want to figure out what> > elements are coordinated with the heavy metal in the> > first coordinate. Since the oxygen and nitrogen have> > similar scattering factors, how can I differetiate> > them? Using shell-by-shell fitting or linear> > combination fitting with standards? Thanks.> > >> > > Best wishes,> > >> > > Mengqiang Zhu> > >> > >> > >> > >> > >> > >> > >> > > -----------------------> > > Mengqiang Zhu> > > Ph.D Candidate> > > Environmental Soil Chemistry> > > Department of Plant and Soil Sciences> > > University of Delaware> > > 152 Townsend Hall> > > Newark, DE 19716> > > ! http://ag.udel.edu/soilchem/zhu.html> > > _______________________________________________> > > Ifeffit mailing list> > > Ifeffit@millenia.cars.aps.anl.gov> > >> > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit> >> > ------------------------------------------------> >> > 블로그에 윈도우 라이브> > 메신저(베타)를 홍보해! 주시는 모든> > 분께 선물을 드립니다! 홍보하기> >________________> >_______________________________________________> >Ifeffit mailing list> >Ifeffit@millenia.cars.aps.anl.gov> >http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit> > _______________________________________________> Ifeffit mailing list> Ifeffit@millenia.cars.aps.anl.gov> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit

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