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

The partial structural change in cage-opened C 60 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 λ edge 880 to 800 nm. The replacement of a ketone with a sulfide moiety changes the electronic properties of cage-opened fullerene ylides, thus causing a hypsochromic shift in absorption and a cathodic shift of reduction potentials.