View Full Version : Help reading IR charts?
twotimintim
2008-11-13, 16:08
Hey guys. I jsut did an experiment wherein we made some polysiloxanes, I got the IR spec charts for them. (with the wavenumber in 1/cm)
Now I also ahve some refererence charts, but they are wavenumber in microns , and they seem to be flipped.
I am fairly decent at doing Organic IR spec, but not so much inorganic
Any tips on comparing the my run with the published one?
that all makes sense. the 1/cm (wavenumber) scale is going to be different than the micron scale, as a longer wavelength is going to be a smaller wavenumber. when you compare them, just pick the biggest / most important peaks and convert those peaks. no need to convert the whole spectrum.
use this http://www.spectralcalc.com/convert/convert.php (select spectral units as the type).
but to be honest, i would throw out the outdated micron reference charts and grab something from the web.
my favorite website for literature spectra is http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi (yes, i have a favorite spectral database :) )
if you made something a little more obscure, it probably won't be on there, but with a little thinking you should be able to dig up something similar. try a search for %siloxane if you are really having troubles and scroll through to find something.
there is really no difference between this and a normal organic molecule, the only new peaks you will see are the Si-O and Si-C, everything else is the usual (+/- inductive effects etc).
twotimintim
2008-11-14, 02:51
awesome help. thanks man, I did end up converting the peaks. That database will be of help in the future though