Anisotropic Electron Conductance Driven by Reaction Byproducts on a Porous Network of Dibromobenzothiadiazole on Cu(110)

Abstract

Efficiency in charge‐transport is a fundamental but demanding prerequisite to allow better exploitation of molecular functionalities in organic electronics and energy‐conversion systems. Here, we report on a mechanism that enables a one‐dimensional conductance structure by connecting discrete molecular states at 2.1 eV through the pores of a metal–organic network on Cu(110). Two adjacent, periodic and isoenergetic contributions, namely a molecular resonance and the confined surface‐state, add‐up leading to anisotropic structures, as channels, observable in real‐space conductance images. The adsorption configurations of Br atoms, inorganic byproduct of the redox‐reacted 4,7‐dibromobenzo[c]‐1,2,5‐thiadiazole (2Br‐BTD) molecules on the copper surface, drive the confinement of the Cu surface state within the pores and critically control the channel continuity. Small displacements of the Br atoms change the local surface potential misaligning the energy levels. This work visualizes the effect of order‐disorder transitions caused by the movement of single atoms in the electronic properties of two‐dimensional organic networks.

Thioetherification of Br-Mercaptobiphenyl Molecules on Au(111)

“…A careful structural characterization of these assemblies provides already the first hint that these structures cannot be described according to the Ullmann and Au-disulfide reaction schemes mentioned in literature ,− and expected for the two individual terminal groups. Indeed, the 1.1 nm long molecular segment included between two subsequent bents in chains and loops is only about the size of the biphenyl group of one pristine MBP molecule.…”

“…This critical length is too short to justify the formation of the extensively characterized Ullmann C–C cross-coupling reaction, although the thermally induced detachment of the halogen atom is observed (Supporting Information SI2). − …”

Empowering non-covalent hydrogen, halogen, and [S–N]2 bonds in synergistic molecular assemblies on Au(111)

“…23–25 Indeed, very often, these interactions are masked by strong covalent bonds in metal–organic assemblies, or by the interaction with the supporting metal surfaces. 26–30…”

“…[23][24][25] Indeed, very often, these interactions are masked by strong covalent bonds in metal-organic assemblies, or by the interaction with the supporting metal surfaces. [26][27][28][29][30] Here, we report on the multiple secondary bonds leading to the assembly of one molecular species, namely 4,7-dibromobenzo[c]-1,2,5-thiadiazole (2Br-BTD), in two ordered networks supported on Au(111) surface (ESI1-3 †). We demonstrate that, favoured by the weak molecular interaction with the Au surface, the cohesion of the two assemblies is driven by the synergistic interaction of sulphur (S), nitrogen (N), hydrogen (H) and bromine (Br) atoms.…”

“…Our DFT calculations confirm the weakness of this coupling, which is essential to observe the synergistic contribution of the secondary bonds in the two assemblies, a contribution that is hidden in the metal-organic network formed by 2Br-DBT molecules on Cu(110). 27,28 Fig. 2 shows higher-resolution STM images and DFT models of the two structures referred to as phase 1 (P1) and phase 2 (P2).…”