Subphthalocyanine Platform for Single-Molecule Machines on Surface: Ligand-Directed Adsorption on Au(111)

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

Abstract

For the development of single-molecule machines on surfaces, a vertical molecular geometry based on a simple, common platform is a promising design approach. This could allow decoupling of the active unit from the supporting surface and obtaining of a flexible modular system. An ideal platform for this purpose is subphthalocyanine with its bowl-shaped geometry and axial functionalization. We functionalized SubPcs with a series of vertical, axial ligands with varying conjugation lengths. Their adsorption on the Au(111) surface was studied by low-temperature scanning tunneling microscopy, supported by simulations. We found that increasing the conjugation length of the axial ligand induces a distinct transition in the adsorption geometry. Long ligands, such as azobenzene and naphthalene derivatives, adopt a reverse adsorption geometry with the ligand adsorbed flat on the surface and the SubPc platform pointing upward. These reverse molecules further interact, forming one-dimensional chains. The intermolecular arrangement and distances in the chains are determined by the orientation of the axial ligand on the surface. In contrast, the shortest ligand, which is formed by a single phenyl ring derivative, predominantly adsorbs with the SubPc platform on the surface and allows rotation by the STM tip. Our findings reveal a clear structure–adsorption relationship and offer a rational strategy to control the orientation and packing of SubPc-based single-molecule machines on surfaces through the design of the axial ligands.

Details

OriginalspracheEnglisch
Seiten (von - bis)9139–9146
Seitenumfang8
FachzeitschriftACS Nano
Jahrgang20
Ausgabenummer11
Frühes Online-Datum12 März 2026
PublikationsstatusVeröffentlicht - 24 März 2026
Peer-Review-StatusJa

Externe IDs

ORCID /0000-0002-1747-3838/work/209580358
ORCID /0000-0001-9607-8715/work/209582257
unpaywall 10.1021/acsnano.5c17283
Scopus 105033786895

Schlagworte

Schlagwörter

  • Au(111), axial ligands, molecular simulation, scanning tunneling microscopy, subphthalocyanine