Reversible Diels–Alder Addition to Fullerenes: A Study of Dimethylanthracene with H(2)@C(60)

The study of isolated atoms or molecules inside a fullerene cavity provides a unique environment. It is likely to control the outer carbon cage and study the isolated species when molecules or atoms are trapped inside a fullerene. We report the Diels–Alder addition reaction of 9,10-dimethyl anthracene (DMA) to H(2)@C(60) while (1)H NMR spectroscopy is utilized to characterize the Diels–Alder reaction of the DMA with the fullerene. Through (1)H NMR spectroscopy, a series of isomeric adducts are identified. The obtained peaks are sharp, precise, and straightforward. Moreover, in this paper, H(2)@C(60) and its isomers are described for the first time.