Formation of methylene derivatives of [60]-, [70]-, [78]- and [84]-fullerenes by reaction of fullerene-containing soot extract with tetrahydrofuran

If a mixture of carbon clusters extracted from soot produced by the arc-discharge procedure is either heated or sonicated with tetrahydrofuran (THF), a range of methylene derivatives Cm[CH2]n, where m is 60, 70, 78 or 84 and n is variously 1–6 are produced. These results constitute the first formation of [78]fullerene derivatives; [76]fullerene does not appear to react under these conditions. Species with n= 3 are dominant, believed to be due to addition of trimethylene chains, through loss of formaldehyde from THF. This conclusion is supported by the prominence of [CH2]4 adducts in the product if [60]fullerene is heated under reflex with dihydropyran. Reaction of pure [60]fullerene with THF results in the addition of up to 10 methylene groups to the cage.