Novel π-Conjugated Systems: The First Silatropylium Ion and Planar Cyclooctatetraene Annelated with Bicyclic Frameworks and New Derivatives of Fullerene C60 (ORGANIC MATERIALS CHEMISTRY-High-Pressure Organic Chemistry)

Abstract

The first silylium ion with cyclic π-conjugation, the silatropylium ion, was prepared, which was made possible by annelation with three bicyclo[2.2.2]octene frameworks and steric protection of the silyliumion center by a mesityl group. The presence of cyclic π-conjugation through the p-orbital of silicon was confirmed by NMR measurements. The first planar cyclooctatetraene was synthesized by cuprate mediated cyclotetramerization of 2, 3-diiodobicyclo[2.1.1]hexene, and its structure determined by X-ray crystallography. On the other hand, a thermal reaction of fullerene C60 with phthalazine in solution afforded a C60 derivative with an eight-membered-ring opening on the surface while the reaction conducted in the solid state gave a novel adduct with two C60 cages incorporated in a bicyclic framework.