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.