Center S3, CNR Institute of Nanoscience, Via Campi 213/A, 41121 Modena, Italy.
Langmuir. 2013 Aug 20;29(33):10505-12. doi: 10.1021/la401645k. Epub 2013 Aug 8.
Azobenzene self-assembled monolayers (SAMs) are examples of optomechanical nanostructures capable of producing mechanical work through the well-known azobenzene photoisomerization process. Experimental studies have provided information on their structural properties, but an atomistic description of the SAMs in both the cis and trans forms is still lacking. In this work, a computational investigation of the SAM structures is conducted by classical molecular dynamics with a dedicated force. Experimental data on the SAM unit cell is used to set up SAM models of different molecular densities. The optimal structures are identified through the comparison with structural data from X-ray photoelectron and near-edge X-ray absorption fine structure spectroscopies. The resulting SAM atomistic models are validated by comparing simulated and experimental scanning tunneling microscopy images.
偶氮苯自组装单分子层（SAMs）是光机械纳米结构的示例，它们能够通过众所周知的偶氮苯光致异构化过程产生机械功。实验研究提供了有关其结构特性的信息，但在顺式和反式两种形式下对 SAM 的原子级描述仍然缺乏。在这项工作中，通过具有专用力的经典分子动力学对 SAM 结构进行了计算研究。使用 SAM 单元的实验数据来建立不同分子密度的 SAM 模型。通过与 X 射线光电子能谱和近边 X 射线吸收精细结构光谱学的结构数据进行比较，确定了最佳结构。通过比较模拟和实验扫描隧道显微镜图像来验证所得 SAM 原子级模型。
