Atomic‐Scale Visualization of the Stepwise Metal‐Mediated Dehalogenative Cycloaddition Reaction Pathways: Competition between Radicals and Organometallic Intermediates

Abstract

Dehalogenative cycloaddition reaction is apowerful strategy to generate new ring scaffolds with p-conjugated features on as urface,a nd thus holds great promise toward atomically precise electronic devices or nanomaterials.T he ortho-dihalo substitution provides ag ood strategy to realize cycloaddition. However,t he limited understanding of intermediate states involved hinders mechanistic exploration for further precise design and optimization of reaction products. Now,t he evolutions of competing surface-stabilized radicals and organometallic intermediates in real space were visualized towardthe formation of dominant conjugated four-membered ring connections.F rom the interplay of scanning tunneling microscopya nd density functional theory calculations,t he stepwise metal-mediated dehalogenative cycloaddition pathway is elucidated both experimentally and theoretically.T he results provide fundamental insights into the intermediate states involved in on-surface synthesis.

On-Surface Synthesis of Chlorinated Narrow Graphene Nanoribbon Organometallic Hybrids

“…They potentially allow rational fine-tuning of the electronic, electrochemical, optical, and magnetic properties by controlling both the chemical structures of the organic ligands and the metallic centers. For instance, Osuka and collaborators have developed long molecular ladders comprising up to 24 porphyrin subunits. , However, the stepwise synthesis of such systems in solution is complex and time-consuming, and thus it is tempting to explore on-surface polymerization as a rapid and efficient route to fused organometallic complexes. − …”

Orbital-symmetry effects on magnetic exchange in open-shell nanographenes

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