Posts Tagged ‘Gilbert Lewis’

Intermolecular atom-atom bonds in crystals? The O…O case.

Saturday, July 25th, 2015

I recently followed this bloggers trail; link1link2 to arrive at this delightful short commentary on atom-atom bonds in crystals[1] by Jack Dunitz. Here he discusses that age-old question (to chemists), what is a bond? Even almost 100 years after Gilbert Lewis’ famous analysis,[2] we continue to ponder this question. Indeed, quite a debate on this topic broke out in a recent post here. My eye was caught by one example in Jack's article: "The close stacking of planar anions, as occurs in salts of croconic acid …far from producing a lowering of the crystal energy, this stacking interaction in itself leads to an increase by several thousand kJ mol−1 arising from Coulombic repulsion between the doubly negatively charged anions" I thought I might explore this point a bit further in this post.



  1. J.D. Dunitz, "Intermolecular atom–atom bonds in crystals?", IUCrJ, vol. 2, pp. 157-158, 2015.
  2. G.N. Lewis, "THE ATOM AND THE MOLECULE.", Journal of the American Chemical Society, vol. 38, pp. 762-785, 1916.