On-surface
C–C coupling reactions of molecular precursors with alkynyl
functional groups demonstrate great potential for the controllable
fabrication of low-dimensional carbon nanostructures/nanomaterials,
such as carbyne, graphyne, and graphdiyne, which demand the incorporation
of highly active sp-hybridized carbons. Recently, through a dehydrogenative
homocoupling reaction of alkynes, the possibility was presented to
fabricate surface nanostructures involving acetylenic linkages, while
problems lie in the fact that different byproducts are inevitably
formed when triggering the reactions at elevated temperatures. In
this work, by delicately designing the molecular precursors with terminal
alkynyl bromide, we introduce the dehalogenative homocoupling reactions
on the surface. As a result, we successfully achieve the formation
of dimer structures, one-dimensional molecular wires and two-dimensional
molecular networks with acetylenic scaffoldings on an inert Au(111)
surface, where the unexpected C–Au–C organometallic
intermediates are also observed. This study further supplements the
database of on-surface dehalogenative C–C coupling reactions,
and more importantly, it provides us an alternative efficient way
for incorporating the acetylenic scaffolding into low-dimensional
surface nanostructures
