Submitted by Julia C. / University of California Davis on Wed, 11/30/2011 - 19:38

Greetings VIPErs,

I am looking for molar absorptivity (or molar extinction coefficient) data for a handful of inorganic compounds (in solution), as a function of wavelength in the UV/visible spectrum. Can you help?

The compounds are Co(NO3)2, CoCl2, K2CrO7, AuCl3, K2CrO4, NiCl2, CuSO4, and KMnO4.

I have tried the following online resources without success: the CRC Handbook, the NIST Chemical WebBook, the Combined Chemical Dictionary, PubChem, SciFinder, and Google.

I would greatly appreciate your suggestions for resources that may have these data! If the search is to no avail, I will probably resort to tracking down a UV/vis spectrophotometer (and the various chemicals) and taking the measurements myself, but I would hugely appreciate a more reliable source, in addition to not having to do this.

Many thanks!

Kurt Birdwhistell / Loyola University New Orleans

The first two in your list you should be looking up [Co(OH2)6]2+.  and for NiCl2 you should be looking at [Ni(OH2)6]2+.  Did you try looking these compounds up using Scifinder scholar.  Then look at the physical parameters page. 



Fri, 12/02/2011 - 11:21 Permalink
Jeffrey Bodwin / Minnesota State University Moorhead

Hmm, grade papers and do administrivia, or do some fun science for a little while...  I think I'll do SCIENCE!!

We don't have AuCl3 on the shelf, and the CoCl2 solution was just a tiny bit cloudy, but I ran the rest of these samples.  Data is at and I took a picture of the samples .  Oooo, pretty...

Any questions about them, let me know.

Fri, 12/09/2011 - 13:01 Permalink
Julia C. / University of California Davis

Your data, and photo, are awesome!  Thank you so much for collecting these data to share with me--I am just amazed by your kindness and generosity with your time and resources!

Many, many thanks,


Sun, 12/11/2011 - 16:32 Permalink
Joanne Stewart / Hope College

Dear Jeff,

The link to your data still works (so cool), but the link to the photo seems broken. Would it be possible to fix it?

Thanks, Joanne

Mon, 12/17/2012 - 12:01 Permalink