Talk:Ethylenetetracarboxylic dianhydride

Additional references
The Taherpour paper lists the following references as "previous attempts" but it is not clear whether they succeeeded or not:
 * [7] J.M. Patterson, N.B. Haidar, L.L. Braun, W.T. Smith Jr., J. Anal. Appl. Pyrol. 2 (1981) 331–337.
 * [8] V.D. Kiselev, G.G. Iskhakova, Y.G. Shtyrlin, A.I. Konovalov, Zhu. Org. Khim. 29 (6) (1993) 1111–1115.
 * [10] J. Sauer, B. Schroeder, A. Mielert, Chem. Berichte 100 (1) (1967) 315–322.
 * [11] J. Sauer, B. Schroeder, R. Wiemer, Chem. Berichte 100 (1) (1967) 306–314.

If I ever get a round tuitt, I may check them... All the best, --Jorge Stolfi (talk) 18:24, 3 January 2010 (UTC)
 * I got the abstract of Patterson (1981), and it claims that pyrolysis of the acid at the right temperature yields the dianhydride (among other things). So he gets the priority, I guess. --Jorge Stolfi (talk) 02:56, 4 January 2010 (UTC)
 * Oops, J. Sauer, B. Schroeder, R. Wiemer also have it in (1967). Not clear whther they were the first either.
 * Jürgen Sauer, Barbara Schröder, Richard Wiemer (1967), Eine Studie der Diels-Alder-Reaktion, VI. Kinetischer Nachweis des Moleküls C6O6 (Dianhydrid der Äthylentetracarbonsäure). Chemische Berichte Volume 100 Issue 1, Pages 306-314
 * Jürgen Sauer, Barbara Schröder, Albrecht Mielert (1967), Eine Studie der Diels-Alder-Reaktion, VII. Reaktionen des Dianhydrids der Äthylentetracarbonsäure (C6O6). Chemische Berichte Volume 100 Issue 1, Pages 315-322

Alternative structure
The structure shown in the infobox pic is given in Taherpour's paper. However the reaction path conjectured in that paper suggests an alternative structure, namely two malonic anhydride rings connected by a double bond in the 3 position. I cannot figure out wether Taherpour has ruled it out, and I can access the abstracts of the three earlier articles. Could someone please check that? Thanks... All the best, --Jorge Stolfi (talk) 06:21, 19 February 2010 (UTC)
 * I don't have the full Taherpour paper, but I assume he matched his product to known spectroscopic data of the compound? Constraint (or not) of the alkene stretch and different electronic characteristics for the carbonyl/alkene bond rotation should make them distinguishable, but not sure there is enough real or calculated data on the known possibilities to assign "this not that" vs just "looks like this". DMacks (talk) 07:01, 19 February 2010 (UTC)
 * The paper states "The structure was confirmed by the analytical methods and compared to the previous reported results." so they just matched, not proved from a direct structural analysis of their compound. DMacks (talk) 20:52, 24 February 2010 (UTC)


 * And thinking deeper, malonic anhydride is a highly strained structure (4-membered ring, and one with 3 sp2 centers!), seems less likely than the proposed 5-membered ring structure. I made the diagram at right so we can make sure we're talking about the same ideas. DMacks (talk) 21:08, 24 February 2010 (UTC)