Surface-assisted fabrication of low-dimensional carbon-based nanoarchitectures

Abstract

On-surface synthesis, as an alternative to traditional in-solution synthesis, has become an emerging research field and attracted extensive attention over the past decade due to its ability to fabricate nanoarchitectures with exotic properties. Compared to wet chemistry, the on-surface synthesis conducted on atomically flat solid surfaces under ultrahigh vacuum exhibits unprecedented characteristics and advantages, opening novel reaction pathways for chemical synthesis. Various low-dimensional nanostructures have been fabricated on solid surfaces (mostly metal surfaces) based on this newly developed approach. This paper reviews the classic and latest works regarding carbon-based low-dimensional nanostructures since the arrival of on-surface synthesis era. These nanostructures are categorized into zero-, one-and two-dimensional classes and each class is composed of numerous sub-nanostructures. For certain specific nanostructures, comprehensive reports are given, including precursor design, substrate choice, synthetic strategies and so forth. We hope that our review will shed light on the fabrication of some significant nanostructures in this young and promising scientific area.

Theoretical Modeling of the Metal‐Organic Precursors of Anthracene‐Based Covalent Networks on Surfaces

“…[1][2][3][4][5] In this field, an efficient way to create polymeric structures on solid substrates has been the Ullmann coupling reaction. [6][7][8] During this transformation halogenated organic tectons adsorbed on catalytically active metallic surfaces (e. g. Cu(111), Ag(111), Au(111)), usually under high vacuum conditions, lose halogen atoms and use the resulting reactive centers to form covalent CÀ C bonds. To date, numerous experimental studies of the Ullmann reaction have been performed in which such molecules as terphenyls, [9,10] polyaromatic hydrocarbons (PAHs), [11][12][13][14] porphyrins [15,16] and others [17,18] with differently introduced halogen atoms were used.…”

“…Surface‐assisted fabrication of low‐dimensional covalent molecular structures has been recently recognized as a versatile route to new nanomaterials with unique properties [1–5] . In this field, an efficient way to create polymeric structures on solid substrates has been the Ullmann coupling reaction [6–8] . During this transformation halogenated organic tectons adsorbed on catalytically active metallic surfaces (e. g. Cu(111), Ag(111), Au(111)), usually under high vacuum conditions, lose halogen atoms and use the resulting reactive centers to form covalent C−C bonds.…”

Sequential Activation of Aromatic C─H Bonds on Cu(111)

“…However, C–H activation is fairly challenging due to the inertia of C–H bonds as well as the poor selectivity. To overcome this, diverse strategies have been adapted, inclusive of harsh experimental conditions, transition metal catalysis, and metal surfaces. , Among them, metal surface-assisted C–H activation has drawn considerable attention in recent decades, where the metal surfaces usually serve as both platform and catalyst. The two-dimensional confinement and catalytic effect of the metal surfaces have a significant impact on the C–H activation process.…”

“…For the intramolecular reaction via C–H activation, the most typical products are nanographenes − and graphene nanoribbons − exhibiting fascinating electronic and magnetic properties. For the intermolecular case, the C–H activation exhibits great potential in the fabrication of zero-, one-, and two-dimensional nanosystems. ,− …”

Synthesis of the Two-Dimensional Robust Kagome Lattice on Au(111) via the Introduction of Fe Atoms

“…Theoretical studies proposed that 2D organic hexagonal or Kagome lattices may possess robust topological surface states. − Thereafter, the search for 2D organic topological insulators has acquired extensive interests recently. − On-surface chemistry, − by which the specific chemical reactions can be studied at the single molecular scale, is considered to be an ideal methodology to fabricate 2D molecular tessellations. To date, Kagome lattices can be built on metal surfaces through various intermolecular interactions, such as van der Waals forces, , hydrogen bonds, , and metal–organic coordinations. − Weak molecule–molecule and molecule–substrate interactions usually lead to limited thermal stabilities, resulting in significant molecular desorption or the collapsing of the self-assembly islands at elevated temperatures.…”