Comments on: The history of stereochemical notation: a search for the earliest example.

By: Henry Rzepa

Henry Rzepa — Thu, 13 Sep 2012 06:45:18 +0000

A digression, but the diagram captioned as by Wells is presumably of diborane, the bridging structure having been famously suggested in 1943 by Longuet-Higgins and Bell (DOI: 10.1039/JR9430000250), but not illustrated as clearly as by Wells. But the oddity is why represent the boron atoms as being so much smaller than the hydrogen? I do not have immediate access to the article referred to (A. F. Wells, Structural Inorganic Chemistry, Clarendon, Oxford, 1945).

By: Henry Rzepa

Henry Rzepa — Wed, 12 Sep 2012 19:09:07 +0000

Thanks Lukas. Perhaps the surprising aspect is that it has taken until 2012 to write a published history of this aspect of notation. And that (apart from CIP), the originators of notation rarely get full recognition. Even by 1956, the use of this now ubiquitous stereochemical notation was not common; thus Woodward appears not to have endorsed it.

Since the reference you give is a large download, I have taken the liberty of quoting the figure you refer to here:

By: Look@s

Look@s — Wed, 12 Sep 2012 18:50:46 +0000

Addendum: Dotted lines and thick lines used in combination already by R. Kuhn in 1932, see Jensens article.

By: Look@s

Look@s — Wed, 12 Sep 2012 18:47:02 +0000

Henry,

I have found that with questions about historical facts in chemistry, there are a few incredibly knowledgeable historians of chemistry, among them Prof. William B. Jensen, just retired from the Univ. of Cincinnati.

He has a regular column in the J. Chem. Educ. entitled “Ask a historian”. Those contributions he has collected in a PDF file and you can download them (24 MB) from here

As it happens, he has just written a column entitled “Origin of Stereochemical Line and Wedge Symbols” (page 109). It says at the end that the text has been submitted to the J. Chem. Educ. in 2012, but I have not yet seen it online.

The funny thing is, he also cites a source from 1956 (Cram and Hammond) as the first appearance in print, but a different one. Maybe you want to inform Dr. Jensen about your finding. In addition he shows earlier examples of wedges dating back to the 1930s.