Does F4TCNQ Adsorption on Cu(111) Form a 2D-MOF?

Pengcheng Ding; Mona Braim; A L Hobson; L A Rochford; P T P Ryan; D A Duncan; T-L Lee; H Hussain; G Costantini; Miao Yu; D P Woodruff

doi:10.1021/acs.jpcc.3c04927

Does F₄TCNQ Adsorption on Cu(111) Form a 2D-MOF?

J Phys Chem C Nanomater Interfaces. 2023 Oct 12;127(42):20903-20910. doi: 10.1021/acs.jpcc.3c04927. eCollection 2023 Oct 26.

Authors

Pengcheng Ding^{1

2}, Mona Braim¹, A L Hobson^{1

3}, L A Rochford³, P T P Ryan^{3

4}, D A Duncan³, T-L Lee³, H Hussain³, G Costantini^{5

6}, Miao Yu², D P Woodruff¹

Affiliations

¹ Department of Physics, University of Warwick, Coventry CV4 7AL, U.K.
² Laboratory for Space Environment and Physical Sciences, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
³ Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxford OX11 0DE, U.K.
⁴ Department of Materials, Imperial College London, London SW7 2AZ, U.K.
⁵ Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.
⁶ School of Chemistry, University of Birmingham, Birmingham B15 2TT, U.K.

Abstract

The results of a quantitative experimental structural investigation of the adsorption phases formed by 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane (F₄TCNQ) on Cu(111) are reported. A particular objective was to establish whether Cu adatoms are incorporated into the molecular overlayer. A combination of normal incidence X-ray standing waves, low-energy electron diffraction, scanning tunneling microscopy, and X-ray photoelectron spectroscopy measurements, complemented by dispersion-inclusive density functional theory calculations, demonstrates that F₄TCNQ on Cu(111) does cause Cu adatoms to be incorporated into the overlayer to form a two-dimensional metal-organic framework (2D-MOF). This conclusion is shown to be consistent with the behavior of F₄TCNQ adsorption on other coinage metal surfaces, despite an earlier report concluding that the adsorption structure on Cu(111) is consistent with the absence of any substrate reconstruction.