Capped fullerenes: Stabilization of water-soluble fullerene monomers as studied by flash photolysis and pulse radiolysis
Capped fullerenes: Stabilization of water-soluble fullerene monomers as studied by flash photolysis and pulse radiolysis
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DOI：
10.1021/jp9702863
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发表时间：
1997-05-22
影响因子：
2.9
通讯作者：
Guldi, DM
中科院分区：
文献类型：
--
作者：
Guldi, DM
C-60与亲水基团的官能化促进了富勒烯核的水溶性，从而导致在水溶液中形成不可逆的团簇。研究发现，用表面活性剂(十六烷基三甲基氯化铵或Triton X-100)覆盖水溶性富勒烯衍生物的表面，可以排除富勒烯除尘器的形成，进而稳定富勒烯单体。用闪光光解和脉冲辐解技术产生了富勒烯单体和富勒烯簇合物1-3的激发态和还原态。富勒烯的聚集对与激发态的产生和寿命有关的物理化学性质没有显著影响。对光激发后过程的纳秒研究表明，单体和胶体衍生物1-3在相应的*T-1--和*T；*T吸收的最大吸收峰上存在显著差异。研究发现，簇合物对富勒烯激发三重态的衰变也有显著的影响。类似地，pi-自由基阴离子1-3的λ(Max)对容纳组件的环境参数非常敏感。在表面活性剂介质中，最大峰([(C-60(.-))(C4H10N+)](表面活性剂)1010 nm)相对于类似的γ-Cd络合物([(C-60(.-))(C4H10N+)]/γ-Cd 1030 nm)普遍蓝移。在与……比较的基础上。有证据表明，富勒烯单体存在于核(富勒烯)-壳(表面活性剂)型结构中。
Functionalization of C-60 with hydrophilic groups promotes the water solubility of the fullerene core which leads in aqueous solution to the irreversible formation of clusters. Capping the surface of water-soluble fullerene derivatives with surfactants (cetyltrimethylammonium chloride or Triton X-100) was found to exclude formation of fullerene dusters and, in turn, to stabilize fullerene monomers. Flash photolytic and pulse radiolytic techniques were employed to generated excited and reduced states of fullerene monomers and fullerene clusters 1-3. Fullerene aggregation was found to have no significant effects on the physicochemical properties related to the generation and lifetime of the excited singlet state. Nanosecond studies of the processes following photoexcitation revealed noticeable differences between monomeric and colloidal derivatives 1-3 for the absorption maximum of the corresponding *T-1 --> *T, absorptions. Clustering was found to invoke also remarkable changes for the decay of the fullerene's excited triplet state. Similarly, lambda(max) of the pi-radical anions 1-3 is very sensitive to the environmental parameters of the accommodating assembly. In surfactant media, the maxima ([(C-60(.-))(C4H10N+)](surfactant) 1010 nm) were generally blue-shifted relative to the analogous gamma-CD complexes ([(C-60(.-))(C4H10N+)]/gamma-CD 1030 nm). On the basis of comparison with. fullerene clusters and gamma-CD-incorporated complexes, evidence was found that suggests the presence of fullerene monomers in a core(fullerene)-shell(surfactant) type structure.