[Si(O2 C6 F4 )2 ]14 : Self-Assembly of a Giant Perfluorinated Macrocyclic Host by Low-Barrier Si-O Bond Metathesis.

The dynamic covalent self-assembly of 14 units of bis(perfluorocatecholato)silane leads to [Si(O2 C6 F4 )2 ]14 -the first giant perfluorinated macrocycle. The oligomerization process is monitored spectroscopically, and the macrocycle analyzed by single-crystal X-ray diffraction. The molecule forms a rigid cavity that can host two o-closo-dodecacarboranes. Computations rationalize the consistent and reproducible formation of the 14mer and disclose a non-catalyzed Si-O/ Si-O σ-bond metathesis with an exceptionally low energetic barrier. For the first time, the most prevalent linker in our geosphere-SiO4 -is disposed to construct a shape-defined crystalline macromolecule.