Details

Autor(en) / Beteiligte

• Inayeh, Alex
• Groome, Ryan R. K.
• Singh, Ishwar
• Veinot, Alex J.
• de Lima, Felipe Crasto
• Miwa, Roberto H.
• Crudden, Cathleen M.
• McLean, Alastair B.

Titel

Self-assembly of N-heterocyclic carbenes on Au(111)

Ist Teil von

• Nature communications, 2021-06, Vol.12 (1), p.4034-4034, Article 4034

Ort / Verlag

London: Nature Publishing Group UK

Erscheinungsjahr

2021

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Although the self-assembly of organic ligands on gold has been dominated by sulfur-based ligands for decades, a new ligand class, N-heterocyclic carbenes (NHCs), has appeared as an interesting alternative. However, fundamental questions surrounding self-assembly of this new ligand remain unanswered. Herein, we describe the effect of NHC structure, surface coverage, and substrate temperature on mobility, thermal stability, NHC surface geometry, and self-assembly. Analysis of NHC adsorption and self-assembly by scanning tunneling microscopy and density functional theory have revealed the importance of NHC-surface interactions and attractive NHC-NHC interactions on NHC monolayer structures. A remarkable way these interactions manifest is the need for a threshold NHC surface coverage to produce upright, adatom-mediated adsorption motifs with low surface diffusion. NHC wingtip structure is also critical, with primary substituents leading to the formation of flat-lying NHC 2 Au complexes, which have high mobility when isolated, but self-assemble into stable ordered lattices at higher surface concentrations. These and other studies of NHC surface chemistry will be crucial for the success of these next-generation monolayers. Although N-heterocyclic carbenes (NHCs) are a promising class of ligands for forming robust self-assembled monolayers on metals, many questions remain about their behavior on surfaces. Here, the authors address these fundamental questions—such as the factors controlling NHC orientation, mobility, and ability to self-assemble—through an in-depth examination of NHC overlayers on Au(111).