Octafluorocubane radical anion – the place does the additional electron sit?

Derek Lowe stories the story[1] that the not too long ago synthesized octafluorocubane can take up one electron to kind a radical anion – an electron in a dice. So I assumed it could be enjoyable to compute precisely the place that electron sits!

A ωB97XD/Def2-TZVPPD/SCRF=chloroform calculation (DOI: 10.14469/hpc/11090) is carried out on the impartial system (optimizing its geometry) after which the unconventional anion on the similar geometry. Cubes of whole electron density are evaluated for each after which the impartial kind is subtracted from the anion. The result’s proven under (density isosurface worth 0.0025 au; click on on the picture to load a rotatable 3D mannequin of the density distinction).

The under is on the optimised anion geometry for each species;

The color code is that blue represents the placement of the extra electron, and crimson signifies lowered electron density in comparison with the anion. Arrow 1 reveals an extra sphere of density contained in the dice – sure, an electron in a dice. However you in all probability wouldn’t have anticipated that the outer floor of the dice (arrow 2) can also be surrounded by that electron and there’s a lowered density layer on the within floor of the dice. The C-F bonds have areas of each further density and lowered density.

Postscript: Perfluorododecahedrane added as per remark

Postscript: Perfluorotetrahedrane added for completeness