Posts Tagged ‘free energy change’

Caesium trifluoride: could it be made?

Saturday, November 23rd, 2013
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Mercury (IV) tetrafluoride attracted much interest when it was reported in 2007[1] as the first instance of the metal being induced to act as a proper transition element (utilising d-electrons for bonding) rather than a post-transition main group metal (utilising just s-electrons) for which the HgF2 dihalide would be more normal (“Is mercury now a transition element?”[2]). Perhaps this is the modern equivalent of transmutation! Well, now we have new speculation about how to induce the same sort of behaviour for caesium; might it form CsF3 (at high pressures) rather than the CsF we would be more familiar with.[3] Here I report some further calculations inspired by this report.



  1. X. Wang, L. Andrews, S. Riedel, and M. Kaupp, "Mercury Is a Transition Metal: The First Experimental Evidence for HgF4", Angewandte Chemie International Edition, vol. 46, pp. 8371-8375, 2007.
  2. W.B. Jensen, "Is Mercury Now a Transition Element?", Journal of Chemical Education, vol. 85, pp. 1182, 2008.
  3. M. Miao, "Caesium in high oxidation states and as a p-block element", Nature Chemistry, vol. 5, pp. 846-852, 2013.