Efficient Synthesis of Polyhydroxylated Fullerene Derivatives via Hydrolysis of Polycyclosulfated Precursors

• Published in: Journal of organic chemistry Vol. 59; no. 14; pp. 3960 - 3968
• Main Authors: Chiang, Long Y, Wang, Lee-Yih, Swirczewski, John W, Soled, Stuart, Cameron, Steve
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 01.07.1994; Amer Chemical Soc
• Subjects: Alicyclic compounds; Alicyclic compounds, terpenoids, prostaglandins, steroids; Chemistry; Chemistry, Organic; Exact sciences and technology; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; BUCKMINSTERFULLERENE; AROMATICS; C-60; C60; POLYCARBON SUPERCAGE CHEMISTRY; CHLORINATION; Molecular structure; Photoelectron spectrum; Carbon Molecules; FAB mass spectrum; Atomic cluster; X ray; Sulfatation; Hydrolysis; Polyhedral molecule; Fullerenes; Reaction mechanism; Polyol; Infrared spectrum; NMR spectrum
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo00093a030

Novel cyclosulfation chemistry for the functionalization of C-60 and its analogs is described. The cyclosulfation of C-60 is accomplished in neat fuming sulfuric acid at 55-60 degrees C under N-2 to afford polycyclosulfated fullerene derivatives. Hydrolysis of these derivatives, either in the presence of water at 85-90 degrees C or in aqueous NaOH solution at ambient temperature, gives the corresponding polyhydroxylated fullerenes (fullerenols) in high yield. The functional characteristics and number of sulfate moieties per C-60 molecule in the polycyclosulfated fullerene precursors, and the structure of fullerenols, were determined primarily by the analysis of the TGA-mass spectrum and the sulfur (S-2p) and carbon (C-1s) absorption bands in the XPS spectrum. We resolved an average of 10 to 12 hydroxyl addends in the chemical structure of fullerenols that can be correlated to the structure of polycyclosulfated fullerene precursors containing 5 to 6 cyclosulfate units. The cyclosulfation chemistry is, presumably, initiated by a one-electron oxidation of C-60, followed by the attack of anionic sulfate species on the resulting cationic C-60 radical intermediates, to form the corresponding hydrogen sulfated C-60 radicals. Further oxidation and intramolecular cyclization of this hydrogen-sulfated C-60 yields the polycyclosulfated C-60 products.