jump to navigation

Coronene and the Nazis September 22, 2008

Posted by fetzthechemist in PAHs, Uncategorized.
trackback

There are two main sources of commercial coronene, with vastly different origins. One comes from industrial-scale process deposits and the other from synthesis. The latter is easy to describe.

The Bureau of Community Reference had a program to make high-purity samples of certain PAHs that were to be studied for their biological activities and for their characterization through spectroscopy. All of these were synthesized in large amounts through traditional, unambiguous synthesis routes. It is sold by BCR or one of its agents.

The coronene purchased from most of the chemical supply houses is characterized as different due to its impurities (1). This coronene has traces of benzo[ghi]perylene, benzo[pqr]naphtho[8,1,2-bcd]perylene, naphtho[8,1,2[abc]coronene and ovalene. This indicates a production by some ring-addition mechanism. This was the case.

This material was originally found as yellowish brown deposits in the process pipes of coal liquification processes used by the Germans during World War II to generate motor fuels. These were in short supply due to the Allied enbargo on oil shipments.

Some quantity of these deposits were purchased or obtained by a specialty chemical supplier. Assays after adsorption chromatography and zone refining, showed this material to be about 98 % coronene.

So a little bit of history tied into those bottles of coronene sitting in labs around the world.

Reference

1. W. Schmidt, in “Polycyclic Aromatic Hydrocarbons and Astrophysics”, A. Leger, L. d’Hendecourt, and B. Boccara, eds. Reidel, Dordrecht, The Netherlands, 1987, pp. 149-164

 

Advertisements

Comments»

1. Chip - September 30, 2008

Very interesting note! I’m glad that you pointed this out to me. Here’s the DART mass spectrum of the Aldrich coronene sample that we were discussing on Carbon Based Curiosities, replotted to show the higher-mass impurities.. I see 3 of the four impurities that you mentioned. The label says that it’s 99% pure. Considering the high relative abundances of ovalene and naphtho[8,1,2[abc]coronene , I don’t believe the label!

The link is only good for 2 weeks before the file will be deleted.

2. fetzthechemist - September 30, 2008

Unfortunately, there is no link in your comment. 😦 I’d be interested in how high this goes, as Werner Schmidt showed PAHs with masses at 424 and 448 in the article cited.

You can add the link to your comment or mail it to me at fetzpahs@hotmail.com

This might be publishable as a short note somewhere.

3. Chip - September 30, 2008

Somehow the link to the figure got deleted from my comment. Here it is:

4. Chip - September 30, 2008

I’ll go measure it again to see if I see anything larger, or any trace peaks. It only takes a few seconds once I get in the lab. If you think this is worthy of a note somewhere, I am always glad to collaborate… 🙂

5. Chip - September 30, 2008

I do see trace MH+ peaks at 425 and 449. I’ll crunch the data and send it to you.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: