Unsymmetrical disulfides and thiol mixtures produce different mixed monolayer-protected gold clusters
Unsymmetrical disulfides and thiol mixtures produce different mixed monolayer-protected gold clusters
复制标题
不对称的二硫化物和硫醇混合物产生不同的混合单层保护金簇
作者：
Y. Shon;Carolyn L. Mazzitelli;R. Murray
由不对称二硫化物（HO（CH 2）11 SS（CH 2）11 CH 3）合成混合单层保护的Au簇（MPC），得到HO（CH 2）11 S −和CH 3（CH 2）11 S −硫醇盐组成比为1：1的簇，而硫醇（HO（CH 2）11 SH和CH 3（CH 2）11 SH）1：1混合物反应的产物在单层中主要含有（97%）HO（CH 2）11 S −配体。结果表明，HO（CH 2）11 SH比CH 3（CH 2）11 SH在热力学上优先连接，但在二硫键反应中避免了这种连接。由烷硫醇和二烷基二硫化物合成的MPC的核心尺寸是相似的，这表明硫醇和二硫化物的MPC生长动力学相似。从金（I）-硫醇盐聚合物中间体合成的MPC的组成表明，聚合物在加入还原剂后立即分解。
Synthesis of mixed monolayer-protected Au clusters (MPCs) from unsymmetrical disulfides (HO(CH2)11SS(CH2)11CH3) yields clusters with a 1:1 composition of HO(CH2)11S− and CH3(CH2)11S− thiolates, whereas products from reaction of a 1:1 mixture of thiols (HO(CH2)11SH and CH3(CH2)11SH) contain mostly (97%) HO(CH2)11S− ligands in the monolayer. The results suggest a thermodynamically preferred ligation of HO(CH2)11SH over CH3(CH2)11SH that is circumvented in the disulfide reaction. The core sizes of MPCs synthesized from alkanethiol and dialkyl disulfides are similar, suggesting similar MPC growth dynamics for thiols and disulfides. The compositions of MPCs synthesized starting from gold(I)−thiolate polymer intermediates suggest that the polymer undergoes immediate breakup upon addition of reductant.