The vast majority of the in-isomers of molecules displaying in/out stereoisomerism possess only hydrogen atoms or lone pair electrons as bridgehead substituents, because larger inwardly-directed functional groups are difficult to accommodate in the limited interior space of such macrocycles. The in-fluorosilaphane below has an in-fluorine atom, the largest in-functional group in any well-characterized compound. For a brief communication describing the synthesis and structure of this molecule, see "An in-Fluorosilaphane: The Largest in-Functionality Is a Uniquely Encapsulated Fluorine Atom," S. Dell, N. J. Vogelaar, D. M. Ho, and R. A. Pascal, Jr., J. Am. Chem. Soc. 1998, 120, 6421-6422.