EPR OF ALKYLTHIO MODIFIED GOLD COLLOID

几种Au胶体体系已经通过随后的 长链烷醇单分子膜在其表面上的吸附。 所得的单层膜是高度有序的链长为 10个碳单位或更大。 观察到了不寻常的拉曼光谱 从这些薄膜中，出现了一系列新的拉曼谱带， 电影（nc>10），这与电影直接相关 结晶度 此外，这些条带仅在 当激发波长在620-720范围内时的拉曼光谱 nm;在此范围之外， 膜是唯一观察到的带。 共振过程 与这些拉曼谱带相关的一个峰似乎来自于Au/S 界面区和界面结构的现有模型 支持在聚合物的头基处形成多硫物质， 化学吸附的烷硫醇。 聚硫链预计将在 双自由基，自由基物种的存在可以解释 光学 在红色中出现的吸收。 因此，我们的目标是 确定是否有多硫（或任何自由基物种， 本质）通过EPR存在于膜内。

Several Au colloidal systems have been prepared by subsequent adsorption of long-chain alkanethiol monolayers on their surfaces. The resulting monolayer films are highly ordered for chain lengths of 10 carbon units or greater. Unusual Raman spectra have been observed from these films; a series of new Raman bands appears for longer chain films (nc>10), which has been directly correlated to film crystallinity. In addition, these bands are only observed in the Raman spectra when the excitation wavelength is in the range 620-720 nm; outside this range, the normal group vibrational frequencies of the film are the only bands observed. The resonance process associated with these Raman bands appears to originate from the Au/S interfacial region, and current models of interfacial structure support the formation of polysulfur species at the headgroups of the chemisorbed alkanethiols. Polysulfur chains are expected to be diradicals, and the presence of a radical species would explain the optical absorption appearing so far in the red. Our goal therefore is to ascertain whether or not polysulfur (or any radical species in essence) is present within the film by EPR.