Direct benzyne-C60 addition does not generate a [5,6] open fulleroid

Recent reports describe the different products resulting from the reaction of C60 with benzyne generated from anthranilic acid derivatives and isoamyl nitrate in the presence and absence of triethylamine. Reinvestigation here via 1H, 13C, HMBC NMR and mass spectroscopy elucidates that these products are the [6,6] closed C60-fused δ lactones, and not the [5,6] open fulleroids which would result from benzyne addition. Furthermore, theoretical calculations show that the open isomer [5,6] benzyne addition is less stable than the [5,6] closed isomer as an isolable product.122