Phosphorus ylides of cage-opened sulphide [60]fullerene derivatives.

The partial structural change in cage-opened C60 derivatives by replacing a carbonyl group with a sulphide moiety significantly lowers the chemical stability of the corresponding phosphorus ylides. Thus they readily undergo in situ hydrolysis to give an α-methylene carbonyl compound. Owing to the elevated LUMO level, the near-infrared absorption band was hypsochromically shifted from λedge 880 to 800 nm.