Thermal control of sequential on-surface transformation of a hydrocarbon molecule on a copper surface

Abstract

On-surface chemical reactions hold the potential for manufacturing nanoscale structures directly onto surfaces by linking carbon atoms in a single-step reaction. To fabricate more complex and functionalized structures, the control of the on-surface chemical reactions must be developed significantly. Here, we present a thermally controlled sequential three-step chemical transformation of a hydrocarbon molecule on a Cu(111) surface. With a combination of high-resolution atomic force microscopy and first-principles computations, we investigate the transformation process in step-by-step detail from the initial structure to the final product via two intermediate states. The results demonstrate that surfaces can be used as catalysing templates to obtain compounds, which cannot easily be synthesized by solution chemistry.

Characterizing aliphatic moieties in hydrocarbons with atomic force microscopy

“…High resolution atomic force microscopy (AFM) with functionalized tips 1 is evolving towards a valuable tool for molecular structure identification of synthetic 2–5 and natural 6–8 compounds, and products formed by on-surface synthesis 9–16 and atomic manipulation. 2,10,17,18 Structure identification by AFM has the strategic advantage that one can address individual molecules, i.e.…”

On‐Surface Formation of Cumulene by Dehalogenative Homocoupling of Alkenyl gem‐Dibromides

“…[1][2][3][4][5][6] In general, most of the on-surface reactions follow pathways different from their counterparts in solution because of the effects of the surface: the reactions are confined in two dimensions and the possible catalytic surface activity. [7][8][9][10][11][12][13][14] Consequently, unexpected reactions have been surprisingly discovered in on-surface synthesis experiments, [15][16][17][18][19][20][21][22] and thus, this strategy has opened up a way for the fabrication of a plethora of novel surface nanostructures which may be hardly obtained by traditional solution methods. Among others, the atomically precise synthesis of carbon nanostructures such as graphene nanoribbons [23][24][25][26][27][28][29][30] and other hydrocarbons like alkanes, dienes and diynes has become a hot topic within the field of onsurface synthesis.…”

Mechanistic Insights into Surface-Supported Chemical Reactions

“…The prowess of single molecule bond-resolved AFM measurements is shown in recent studies on enediyne cyclization reactions [4,29,35,36,54]. These reactions are more complex than the reactions presented above, as multiple chemical bonds are affected in such transformations.…”

“…As will be discussed below, whether and which intermediates are stabilized depends on a variety of parameters: the potential-energy landscape, energy flow at the microscopic scale, as well as entropic effects. One of the main parameters that can be controlled is the reaction temperature, the adjustment of which can be used to slow down reaction rates and in certain cases lead to "freezing" of the reaction at different steps (see for example [34][35][36][37][38][39][40][41][42][43][44][45]). Furthermore, it is possible to chemically quench a reaction at a certain step, for instance by use of additional reactants that are dosed to passivate (reversibly or irreversibly) specific reactive centers of intermediates along the reaction pathway.…”