Depositing Molecular Graphene Nanoribbons on Ag(111) by Electrospray Controlled Ion Beam Deposition: Self‐Assembly and On‐Surface Transformations

Abstract

The chemical processing of low-dimensional carbon nanostructures is crucial for their integration in future devices. Here we apply a new methodology in atomically precise engineering by combining multistep solution synthesis of N-doped molecular graphene nanoribbons (GNRs) with mass-selected ultra-high vacuum electrospray controlled ion beam deposition on surfaces and real-space visualisation by scanning tunnelling microscopy. We demonstrate how this method yields solely a controllable amount of single, otherwise unsublimable, GNRs of 2.9 nm length on a planar Ag( 111) surface. This methodology allows for further processing by employing on-surface synthesis protocols and exploiting the reactivity of the substrate. Following multiple chemical transformations, the GNRs provide reactive building blocks to form extended, metal-organic coordination polymers.

Desilylative Coupling Involving C(sp2)–Si Bond Cleavage on Metal Surfaces

“…In contrast to its mature application in solution chemistry, desilylation has been applied in only limited cases in on-surface chemistry and is absolutely focused on C­(sp)–Si cleavage, as shown in Scheme a. − Gao et al first reported the metathesis reaction between TMS–alkynes and aromatic carboxylic acids on the surface, realizing the C­(sp)–Si cleavage . Very soon, Kawai et al developed the desilylative Glaser coupling of 9,10-bis­((trimethylsilyl)­ethynyl)­anthracene on the Cu(111) surface .…”

“…In addition, Mahapatra et al reported the photoactivation of the C­(sp)–Si bond . Besides the TMS group, Ran et al recently disclosed that the tri-isobutylsilyl group on alkynes can also be directly cleaved on the surface . It should also be mentioned that Sun et al reported the silabenzene synthesis via co-depositing silicon atoms and bromo-substituted organic molecules and the following C­(sp 2 )–Si bond activation process .…”

“…26 Besides the TMS group, Ran et al recently disclosed that the tri-isobutylsilyl group on alkynes can also be directly cleaved on the surface. 27 It should also be mentioned that Sun et al reported the silabenzene synthesis via co-depositing silicon atoms and bromo-substituted organic molecules and the following C(sp 2 )−Si bond activation process. 28 Overall, the desilylation involving C(sp 2 )−Si cleavage on the metal surface has never been achieved to date, even a lot of milestone methods involving C(sp 2 )−Si cleavage have been developed and widely utilized in organic synthesis.…”

Mobility Selective Ion Soft-Landing and Characterization Enabled Using Structures for Lossless Ion Manipulation

“…Ion soft landing (ISL) is a preparative MS-based deposition process in which selected gas-phase ions of interest are concentrated into a beam and deposited in vacuum as thin film coatings at energies low enough to preserve the structural and functional integrity of the deposited molecules . The ISL deposition technique presents significant potential for practical uses, − ranging from material synthesis for batteries and nanoelectronics to selective deposition of bioparticles from complex protein assemblies. In ISL, sorting/separation of ions is typically performed based on the mass-to-charge ratio ( m / z ).…”

Controlled Formation of Porous 2D Lattices from C3‐symmetric Ph6−Me‐Tribenzotriquinacene‐OAc3

“…Examples include graphene nanoribbons, flake‐like nanographenes as well as zigzag and holey structures. Perfectly flat, structurally‐confined nanographenes have been produced on surfaces using self‐assembly and on‐surface reactions of mainly planar aromatic precursor molecules [8–12] . Warped precursors, such as extended rubicenes, have been used recently to open the path to defective nanographenes, [13] highly sought after for electronic applications.…”