二硫化四甲基秋兰姆的表面增强拉曼光谱研究

制备了两种简单常用的具有表面增强拉曼(SERS)活性的银基底—银镜和硝酸刻蚀银箔，并应用于二硫化四甲基秋兰姆(福美双)的检测及其结构变化的分析。SERS技术提供了不同浓度下的二硫化四甲基秋兰姆分子的振动信息，发现当其与金属银基底作用后，二硫键断裂，并且通过化学作用吸附在银基底表面。通过分析不同浓度福美双分子吸附在银表面的拉曼光谱，证明其在金属表面存在两种吸附方式即表现为单齿形和双齿形两种几何形状。这些光谱及结构信息有助于理解和检测自然环境中二硫化四甲基秋兰姆及其分解产物。同时也对二硫代氨基甲酸盐类化合物的研究有一定的借鉴意义。

Surface-Enhanced Raman Spectroscopy of Thiuram Pesticide

In the present paper, two SERS-active substrates (silver mirror and HNO₃ etched Ag foil) were prepared for thiuram detecting and studying. SERS can provide the molecular vibrational model and structure information of thiuram at low concentration, thus providing very valuable information regarding the structure of the adsorbed molecules. This technique also allows for the in situ study of this molecule when adsorbed on a silver surface and the identification of the chemical state when they are adsorbed on the surface of silver substrate. The SERS study of thiuram was carried out at several adsorbtion concentrations, revealing that two different coordination complexes having different geometries (monodentate and bidentate) are possible adsorbed on the silver surface. These results have a significant importance regarding the understanding of the potential environmental impact of these molecules.