title: Further studies of fluoride ion entrapment in octasilsesquioxane cages; X-ray crystal structure studies and factors that affect their formation.
abstract: A range of fluoride-encapsulated octasilsesquioxane cage compounds have been prepared using the TBAF route. Our studies suggest that whilst it is relatively straightforward to prepare fluoride-encapsulated octasilsesquioxane cage compounds with adjacent sp(2) carbons, leading to a range of aryl and vinyl substituted compounds, the corresponding sp(3) carbon derivatives are more capricious, requiring an electron withdrawing group that can stabilize the cage whilst not acting as a leaving group. Analysis by X-ray crystallography and solution (19)F/(29)Si NMR spectroscopy of R(8)T(8)@F(-) reveal very similar environments for the encapsulated fluoride octasilsesquioxane cages. Migration of a fluoride ion from inside the cage to outside the cage without breaking the T(8) framework and the possibility of encapsulating other anions within silsesquioxane cages have been also investigated.
authors.affiliation: Department of Chemistry and Analytical Sciences, Open University, Walton Hall, Milton Keynes, UK MK7 6AA. P.G.Taylor@open.ac.uk
authors.forename: Peter G
authors.initials: PG
authors.lastname: Taylor
authors.forename: Alan R
authors.initials: AR
authors.lastname: Bassindale
authors.forename: Youssef
authors.initials: Y
authors.lastname: El Aziz
authors.forename: Manuel
authors.initials: M
authors.lastname: Pourny
authors.forename: Richard
authors.initials: R
authors.lastname: Stevenson
authors.forename: Michael B
authors.initials: MB
authors.lastname: Hursthouse
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Coles