16

Up until now, there have been attempts at synthesizing octafluorocubane, shown below, but success has been elusive.

C8F8 from https://www.science.org/do/10.1126/a9b6212c-ea5f-46c5-af6f-ef3d2d1893f0/full/octafluorocubane.png

Has there been any success, and how might the symmetry and fluorine's electron affinity affect its properties?

Mithoron
  • 4,546
  • 14
  • 40
  • 61
DrMoishe Pippik
  • 32,365
  • 1
  • 35
  • 69

1 Answers1

22

[Caveat: This is not so much a question-and-answer as a desire to share Derek Lowe's article in his inimitable style. Given enough down-votes, I'll delete both Q-&-A. But enjoy the synthesis summary, cited below!]

Yes! The synthesis of perfluorocubane (or octafluorocubane, if you prefer) has been accomplished, as described by Derek Lowe, "[I]t is predicted to have the ability to hold a free electron in the middle of that cube (!) That's because of the C-F bond properties - all the electron density is being pulled towards the F atoms, so the center of the cube really has room for one to sit in there without running into a lot of interference... [T]here are eight sigma-star orbitals from those C-F bonds all pointing into the center of the cage and overlapping, and giving you effectively a stabilized vacant orbital there."

Get more details in Lowe's article!

DrMoishe Pippik
  • 32,365
  • 1
  • 35
  • 69
  • 2
    "Quantum Mechanics: A Hand-Waving Approach" - I'd buy that book if Derek wrote it! – Nicolau Saker Neto Aug 23 '22 at 22:44
  • 2
    I'll upvote if you go into the related HN comments section and straighten-out some of those goofy comments :) – Todd Minehardt Aug 23 '22 at 23:59
  • 5
    @ToddMinehardt, I'd upvote anyone who convinces Lowe to continue his series, Things I Won't Work With, or start another! They're great material for teaching, or just for personal edification and amusement. – DrMoishe Pippik Aug 24 '22 at 02:47
  • I think the electron is trapped by the 8 positively charged carbons. – Kevin Kostlan Aug 25 '22 at 02:10
  • They should try dodecahedrane next! – matt_black Aug 25 '22 at 11:22
  • BTW, realize that though octafluorocubane can trap an occasional electron, one could not produce a bulk sample where each molecule traps an electron due to the total Coulomb (electrostatic) repulsion. "If a pair of charges of 1 C each were 1 m apart, the force of repulsion between the two charges would be 9 billion newton's," from http://www.tecumseh.k12.oh.us/Downloads/Physics_12_23.pdf . Of course, if there's a similar molecule that can cage protons, one could, theoretically, mix the two "clathrates" to make it electrically neutral (if the charges don't unite to make hydrogen). ;-) – DrMoishe Pippik Aug 25 '22 at 16:06
  • @DrMoishePippik one wild idea is to use an alkali metal as the electron source, complexing it with a cryptand, thus $\ce{[M(crypt)^+][C8F8^-]}$. – Oscar Lanzi Feb 26 '23 at 02:12