The negative ion time-of- flight mass spectra of C60 benzyl derivative and C60/polystyrene mixtures were investigated by UV laser desorption. We found that the aggregation of C6o in derivatives and ndt1lres was very d...The negative ion time-of- flight mass spectra of C60 benzyl derivative and C60/polystyrene mixtures were investigated by UV laser desorption. We found that the aggregation of C6o in derivatives and ndt1lres was very different. The mechanisms of the coalescence of C6o and the growth of C60 by capturing small carbon clusters were discussed. We thought that in derivatives the nascent C60 formed from the rupture of the radicals can easily coalesce into large fullerenes through co1lisions, while in mixtures C60 and small carbon clusters can grow into large fullerenes only when C60 and small carbon clusters were in proper ratio, but no coalescence of C60 was observed.展开更多
Three water-soluble β-alanine C 60 adducts with different addition numbers, C 60(NHCH 2CH 2COONa) nH n(n=1,5,9), were synthesized. The products were characterized by FTIR, 1H NMR and elemental analysis. The antioxida...Three water-soluble β-alanine C 60 adducts with different addition numbers, C 60(NHCH 2CH 2COONa) nH n(n=1,5,9), were synthesized. The products were characterized by FTIR, 1H NMR and elemental analysis. The antioxidant activity of these C 60 adducts as the quencher for superoxide anion radical O -· 2 was evaluated by chemiluminescence in the system of pyrogallol-luminol. The results indicate that the three C 60 derivatives are all excellent quencher for superoxide anion radical O -· 2. The concentrations of 50% inhibition are 252, 140, 112 μmol/L respectively. This high efficiency should be attributed to many factors such as the numbers of remaining double bonds, donor effect of amino group and steric effect. However, the above results also suggest the effect of the adducted β-alanine groups is predominated in this system.展开更多
文摘The negative ion time-of- flight mass spectra of C60 benzyl derivative and C60/polystyrene mixtures were investigated by UV laser desorption. We found that the aggregation of C6o in derivatives and ndt1lres was very different. The mechanisms of the coalescence of C6o and the growth of C60 by capturing small carbon clusters were discussed. We thought that in derivatives the nascent C60 formed from the rupture of the radicals can easily coalesce into large fullerenes through co1lisions, while in mixtures C60 and small carbon clusters can grow into large fullerenes only when C60 and small carbon clusters were in proper ratio, but no coalescence of C60 was observed.
文摘Three water-soluble β-alanine C 60 adducts with different addition numbers, C 60(NHCH 2CH 2COONa) nH n(n=1,5,9), were synthesized. The products were characterized by FTIR, 1H NMR and elemental analysis. The antioxidant activity of these C 60 adducts as the quencher for superoxide anion radical O -· 2 was evaluated by chemiluminescence in the system of pyrogallol-luminol. The results indicate that the three C 60 derivatives are all excellent quencher for superoxide anion radical O -· 2. The concentrations of 50% inhibition are 252, 140, 112 μmol/L respectively. This high efficiency should be attributed to many factors such as the numbers of remaining double bonds, donor effect of amino group and steric effect. However, the above results also suggest the effect of the adducted β-alanine groups is predominated in this system.
