[Si(O(2)C(6)F(4))(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(O(2)C(6)F(4))(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‐SiO(4)‐is disposed to construct a shape‐defined crystalline macromolecule.