Cage Doubling: Solvent-Mediated Re-equilibration of a [3 + 6] Prismatic Organic Cage to a Large [6 + 12] Truncated Tetrahedron

We show that a [3 + 6] trigonal prismatic imine (a) cage can rearrange stoichiometrically and structurally to form a [6 + 12] cage (b) with a truncated tetrahedral shape. Molecular simulations rationalize why this rearrangement was only observed for the prismatic [3 + 6] cage TCC1 but not for the analogous [3 + 6] cages, TCC2 and TCC3. Solvent was found to be a dominant factor in driving this rearrangement.