Maksymovych Peter, Sorescu Dan C, Yates John T
Surface Science Center, Department of Chemistry, University of Pittsburgh, Pennsylvania 15260, USA.
J Phys Chem B. 2006 Oct 26;110(42):21161-7. doi: 10.1021/jp0625964.
The chemisorptive bonding of methanethiolate (CH(3)S) on the Au(111) surface has been investigated at a single-molecule level using low-temperature scanning tunneling microscopy (LT-STM) and density functional theory (DFT). The CH(3)S species were produced by STM-tip-induced dissociation of methanethiol (CH(3)SH) or dimethyl disulfide (CH(3)SSCH(3)) at 5 K. The adsorption site of an isolated CH(3)S species was assigned by comparing the experimental and calculated STM images. We conclude that the S-headgroup of chemisorbed CH(3)S adsorbs on the 2-fold coordinated bridge site between two Au atoms, consistent with theoretical predictions for CH(3)S on the nondefective Au(111) surface. Our assignment is also supported by the freezing of the tip-induced rotational dynamics of a single CH(3)SH molecule upon conversion to CH(3)S via deprotonation.
利用低温扫描隧道显微镜（LT-STM）和密度泛函理论（DFT），在单分子水平上研究了甲硫醇盐（CH(3)S）在Au(111)表面的化学吸附键合。CH(3)S物种是通过STM针尖在5K下诱导甲硫醇（CH(3)SH）或二甲基二硫醚（CH(3)SSCH(3)）解离产生的。通过比较实验和计算得到的STM图像，确定了孤立CH(3)S物种的吸附位点。我们得出结论，化学吸附的CH(3)S的S端基吸附在两个Au原子之间的二重配位桥位上，这与CH(3)S在无缺陷Au(111)表面的理论预测一致。通过去质子化将单个CH(3)SH分子转化为CH(3)S时，针尖诱导的旋转动力学的冻结也支持了我们的归属。
