Fullerene epoxides, C60On, having epoxide groups directly attached to the fullerene cage, constitute an interesting class of fullerene derivatives. In particular, the chemical transformations of fullerene epoxides are expected to play an important role in the development of functionalized fullerenes. This is because such transformations can readily afford a variety of mono- or polyfunctionalized fullerene derivatives while conserving the epoxy ring arrangement on the fullerene surface, as seen in representative regioisomeric fullerene polyepoxides. The first part of this review addresses the synthesis and structural characterization of fullerene epoxides. The formation of fullerene epoxides through different oxidation reactions is then explored. Adequate characterization of the isolated fullerene epoxides was achieved by concerted use of NMR and LC-MS techniques. The second part of this review addresses the substitution of fullerene epoxides in the presence of a Lewis acid catalyst. Most major substitution products have been isolated as pure compounds and their structures established through spectroscopic methods. The correlation between the structure of the substitution product and the oxygenation pattern of the starting materials allows elucidation of the mechanistic features of this transformation. This approach promises to lead to rigorous regioselective production of various fullerene derivatives for a wide range of applications.
A positive working photoresist based on octa-O-tert-butyl carbonated C-hexylcalix[4]resorcinarene (t-BOC-h-C4) and p-nitrobenzyl-9,10-dimethoxy-anthracene-2-sulfonate (NDS) as a photoacid generator has been developed. The photoresist consisting of t-BOC-h-C4 (90 wt%) and NDS (10 wt%) showed a sensitivity of 24 mJ/cm2 and a contrast of 8.1, when it was exposed to 365 nm light and postbaked at 90°C for 2 min, followed by developing with a 1% aqueous tetramethylammonium hydroxide (TMAH) solution at room temperature.
Calix[4]resocinarenes(C4-RAs), "C-tertaheptyl-calix[4]resorcinarene [C(7)C4-RA], Ctertaoctyl-calix[4]resorcinarene [C(8)C4-RA], C-tertanonyl-calix[4]resorcinarene [C(9)C4-RA], and C-tertaundecyl-calix[4]resorcinarene [C(11)C4-RA]", were synthesized by the acidcatalyzed condensation of resorcinol and alkylaldehyde. The obtained C4-RAs were welldissolved in common organic solvents and their films were transparent above 300 nm. Therefore, negative working photoresists based on C4-RAs, 4,4'-methylenebis[2,6bis(hydroxymethyl)]phenol (MBHP) as a cross-linker, and a photo-acid generator diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. Particularly, the resist containing C(8)C4-RA had the dissolution property well-controlled by a conventional aqueous base developer [2.38 wt% aqueous tetramethylammonium hydroxide(TMAH) solution]. Thus, the photoresist consisting of C(8)C4-RA (70 wt%), MBHP (20 wt%), and DIAS (10 wt%) showed a sensitivity of 7 mJ cm2 and a contrast of 6.1 when it was exposed to 365 nm light and postbaked at 130 °C for 3 min, followed by developing with the TMAFI developer at room temperature.
A negative working thermally stable and photosensitive polymer 3 based on poly(2-hydroxy-6-methylphenol-co-2,6-dimethylphenol), 2,6-bis(hydroxymethyl)-4-methylphenol (BHMP) as a cross-linker, and a photoacid generator diphenyliodonium 9,10-dimethoxyanthracene-2-sulfonate (DIAS) has been developed. Polymer 3 was prepared by oxidative coupling polymerization of 2-(tetrahydropyran-2-yl)oxy-6-methylphenol 1 with 2,6-dimethylphenol 2 in the molar ratio of 0.85 : 0.15, followed by acid-hydrolysis. Polymer 3 showed excellent transparency above 300 nm in the UV-visible spectrum. The photosensitive polymer containing polymer 3 (72 wt%), MBHP (18 wt%), and DIAS (10 wt%) showed a sensitivity (D"5) of 7.9 mJlcm2 and a contrast (r15) of 9.3 when it was exposed 365 nm light and postbaked at 125 °C for 3 min, followed by developing a 2.38 wt% aqueous tetramethylammonium hydroxide TMAH solution at 25°C.
A range of methyl 2-fluorocyanoester derivatives were synthesized from dimethyl 2-fluoromalonate ester and their efficacy as additives in lithium ion battery (LIB) electrolytes was determined. The role played by the 2-fluorocyanoester additives on battery performance was explored by linear sweep cyclic voltammetry, NMR, GCMS and XPS techniques. For all fluorocyanoester additives studied, initial reduction of the carbonyl group occurs which is then followed by formation of the corresponding radical anion. Possible degradation routes arising from loss of fluoride ion, loss of methyl radicals and cleavage of the carbon-carbon bond were
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