Université-Paris Sud, Orsay, France.
Langmuir. 2010 May 18;26(10):7242-7. doi: 10.1021/la904317b.
A study of the self-assembly of 1,4-benzenedimethanethiol (BDMT; HS-CH(2)-(C(6)H(4))-CH(2)-SH) monolayers on gold is presented. Self-assembled monolayers (SAMs) are characterized by reflection-absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE) measurements. The ensemble of measurements consistently shows that well-organized BDMT SAMs, with "standing-up" molecules, can be obtained on high quality gold films with incubation in n-hexane provided that N(2)-degassed solutions are used and all preparation steps are performed at 60 degrees C in the absence of ambient light. SE data indicate that the optical interface properties of the BDMT-Au system are different from those of simple alkanethiol SAMs. A possible mechanism for the formation of the "standing-up" phase from the lying-down phase via a hydrogen exchange reaction involving chemisorbed lying-down and free dithiol molecules is discussed.
研究了 1,4-苯二甲硫醇（BDMT；HS-CH(2)-(C(6)H(4))-CH(2)-SH）在金表面的自组装单层。通过反射吸收红外光谱（RAIRS）、X 射线光电子能谱（XPS）和光谱椭圆偏振测量（SE）对自组装单层（SAMs）进行了表征。综合测量结果表明，在高质量的金膜上，通过在 N2 脱气溶液中于 60°C 下进行且无环境光照的孵育，可以得到具有“直立”分子的组织良好的 BDMT SAM。SE 数据表明，BDMT-Au 体系的光学界面性质与简单的烷硫醇 SAM 不同。讨论了通过涉及化学吸附的平躺分子和游离二硫醇分子的氢交换反应从平躺相形成“直立”相的可能机制。
