Role of Adatoms for the Adsorption of F4TCNQ on Au(111)

Abstract

Organic adlayers on inorganic substrates often contain adatoms, which can be incorporated within the adsorbed molecular species, forming two-dimensional metal–organic frameworks at the substrate surface. The interplay between native adatoms and adsorbed molecules significantly changes various adlayer properties such as the adsorption geometry, the bond strength between the substrate and the adsorbed species, or the work function at the interface. Here, we use dispersion-corrected density functional theory to gain insight into the energetics that drive the incorporation of native adatoms within molecular adlayers based on the prototypical, experimentally well-characterized system of F4TCNQ on Au(111). We explain the adatom-induced modifications in the adsorption geometry and the adsorption energy based on the electronic structure and charge transfer at the interface.

How the Support Defines Properties of 2D Metal–Organic Frameworks: Fe-TCNQ on Graphene versus Au(111)

“…Similar structures with metal atoms drawn to the support are common in metal-supported MOF systems. 19 , 26 , 30 , 31 The planarized structure is stabilized by the van der Waals interaction between Fe and Au. This is clearly demonstrated by our test computations using the same setup without the vdW correction, in which the planarized model relaxes into the tilted-TCNQ structure.…”