Surface functionalization of cadmium sulfide quantum-confined nanoclusters. 5. Evidence of facile surface-core electronic communication in the photodecomposition mechanism of functionalized quantum dots
Surface functionalization of cadmium sulfide quantum-confined nanoclusters. 5. Evidence of facile surface-core electronic communication in the photodecomposition mechanism of functionalized quantum dots
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DOI：
10.1021/cm980513t
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发表时间：
1999-03-01
影响因子：
8.6
通讯作者：
Pietro, WJ
中科院分区：
文献类型：
--
作者：
Veinot, JGC;Galloro, J;Pietro, WJ
研究了10种不同表面取代硫醇盐封端的30埃硫化镉量子限制纳米团簇的二甲基甲酰胺悬浮液的光诱导分解。HPLC分析表明，分解以恒定速率进行，并仅产生沉淀的簇聚集体和对应于硫醇盐帽的对称二硫化物作为唯一的有机产物。二硫化物光生动力学对远程取代基的Hammett sigma（p）参数的依赖性表明，电子供体和受体都提高了速率，并且被取代基的纳米团簇荧光猝灭效率模仿，这表明涉及量子点：核心和远程取代基之间的容易的电子通信的光分解机制。进一步的证据，该机制是从4-硝基硫醇/4-甲基硫醇混合表面纳米团簇的光分解的产物分配比。
The photoinduced decomposition of dimethylformamide suspensions of 10 different surface-substituted thiolate-capped 30 Angstrom cadmium sulfide quantum-confined nanoclusters was studied. HPLC analysis demonstrates that decomposition proceeds at a constant rate and produces only precipitated cluster aggregates and the symmetric disulfide corresponding to the thiolate cap as the only organic product. The dependence of the disulfide photogeneration kinetics on the Hammett sigma(p) parameter for the remote substituent indicates that both electron donors and accepters enhance the rate and is mimicked by nanocluster fluorescence quenching efficiencies of the substituents, suggesting a photodecomposition mechanism involving facile electronic communication between the quantum dot: core and the remote substituent. Further evidence for the mechanism was obtained from the product distribution ratios of the photodecomposition of a 4-nitrothiolate/4-methylthiolate-mixed surface nanocluster.