Hobson Archie L, Hussain Hadeel, Mousley Philip J, Duncan David A, Braim Mona, Costantini Giovanni, Nicklin Christopher, Woodruff D Phil
Department of Physics, University of Warwick, Coventry CV4 7AL, U.K.
Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE,U.K.
ACS Omega. 2024 Jul 10;9(29):32193-32200. doi: 10.1021/acsomega.4c04860. eCollection 2024 Jul 23.
A structure determination of the commensurate phase formed by 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (FTCNQ) absorbed on Ag(111) is reported. Initial characterization was performed using low-energy electron diffraction and synchrotron radiation photoelectron spectroscopy, with quantitative structural data being provided by normal incident X-ray standing waves (NIXSW) and surface X-ray diffraction (SXRD). NIXSW data show the FTCNQ molecule to adopt a "twisted" conformation on the surface, previously found to be associated with metal adatom incorporation into a 2d-metal-organic framework for FTCNQ on Au(111), Ag(100), and Cu(111). SXRD results provide direct evidence of the presence of Ag adatoms that are found to occupy near-bridge or fcc hollow sites with respect to the underlying surface, at an adsorption height of 2.69 ± 0.10 Å. The results show a consistent pattern of behavior for FTCNQ adsorption on the (111) surfaces of Cu, Ag, and Au.
报道了吸附在Ag(111)上的7,7,8,8-四氰基-2,3,5,6-四氟喹二甲烷(FTCNQ)形成的同相相的结构测定。最初的表征使用低能电子衍射和同步辐射光电子能谱进行，定量结构数据由正入射X射线驻波(NIXSW)和表面X射线衍射(SXRD)提供。NIXSW数据表明，FTCNQ分子在表面采用“扭曲”构象，此前发现这种构象与金属吸附原子掺入FTCNQ在Au(111)、Ag(100)和Cu(111)上的二维金属有机框架有关。SXRD结果提供了Ag吸附原子存在的直接证据，发现这些吸附原子相对于下层表面占据近桥或面心立方空位，吸附高度为2.69±0.10 Å。结果表明，FTCNQ在Cu、Ag和Au的(111)表面上的吸附行为具有一致的模式。
