STM Control of Chemical Reactions: Single-Molecule Synthesis

Abstract

The fascinating advances in single atom/molecule manipulation with a scanning tunneling microscope (STM) tip allow scientists to fabricate atomic-scale structures or to probe chemical and physical properties of matters at an atomic level. Owing to these advances, it has become possible for the basic chemical reaction steps, such as dissociation, diffusion, adsorption, readsorption, and bond-formation processes, to be performed by using the STM tip. Complete sequences of chemical reactions are able to induce at a single-molecule level. New molecules can be constructed from the basic molecular building blocks on a one-molecule-at-a-time basis by using a variety of STM manipulation schemes in a systematic step-by-step manner. These achievements open up entirely new opportunities in nanochemistry and nanochemical technology. In this review, various STM manipulation techniques useful in the single-molecule reaction process are reviewed, and their impact on the future of nanoscience and technology are discussed.

Hot‐Electron‐Mediated Photochemical Reactions: Principles, Recent Advances, and Challenges

“…From previous studies by scanning tunneling microscopy, it is known that chemical reactions can be triggered by tunneling electrons. [33][34][35][36] The role of tunneling electrons may have a similar role as hot electrons generated by surface plasmons in chemical reactions. There may be two possible ways that the hot electrons can induce chemical reactions: (1) The hot electrons can probably inject directly into unoccupied orbits of target molecules and lower the potential of the molecules required by chemical reactions; (2) The hot electrons with higher kinetic energy and higher momentum than other electrons at the Fermi surface may give energy to certain chemical bonds of the molecules to break these bonds, or make them easily broken for the chemical reactions.…”

Rational Synthesis of Fullerenes

“…The on-surface studies are usually conducted on single-crystal surfaces under ultra-high vacuum conditions that offer extraordinary degree of control in the experiments [27]. Moreover, the usage of atomically clean and flat crystal surfaces allows the observation of the reaction process at the single molecule level by means of scanning tunneling microscopy (STM) [28]. Recent progress in this field demonstrates a high potential for the synthesis of complex architectures via ArylAryl coupling of organic precursors on single-crystal metal surfaces [29,30].…”

Two-Dimensional Polymerization and Reaction at the Solid/Liquid Interface: Scanning Tunneling Microscopy Study

“…Hla et al studied the Ullmann reaction steps by STM on the Cu surface. 76,77 The synthesis reaction of biphenyl from iodobenzene include three steps: (a) dissociation of iodobenzene (C6H5I) into phenyl (C6H5) and iodine; (b) diffusion of phenyl to find another phenyl as a reaction partner; (c) association to form biphenyl (C12H10). Figure 4 is a typical schematic image of all the steps of this Ullmann reaction.…”