Homo-coupling of terminal alkynes on a noble metal surface

Cyclotrimerization of arylalkynes on Au(111)

Cyclotrimerization of arylalkynes on Au(111) proceeds readily at modest temperatures, and affords two-dimensional covalently bonded polyphenylene networks.

On-surface azide-alkyne cycloaddition on Au(111)

We present [3 + 2] cycloaddition reactions between azides and alkynes on a Au(111) surface at room temperature and under ultrahigh vacuum conditions. High-resolution scanning tunneling microscopy images reveal that these on-surface cycloadditions occur highly regioselectively to form the corresponding 1,4-triazoles. Density functional theory simulations confirm that the reactions can occur at room temperature, where the Au(111) surface does not participate as a catalytic agent in alkyne C-H activation but acts solely as a two-dimensional constraint for the positioning of the two reaction partners. The on-surface azide-alkyne cycloaddition offers great potential toward the development and fabrication of functional organic nanomaterials on surfaces.

On-surface single molecule synthesis chemistry: a promising bottom-up approach towards functional surfaces

In this review, we introduce recent progress on surface synthesis and focus on supramolecular self-assembled structures driven by several typical chemical reactions at solid surfaces, with the aid of scanning tunneling microscopy (STM). We also emphasize the relationship between the non-covalent self-assembly and surface reactivity, by which we hope to find an effective way for further controllable nano-manufacture.

On-surface polymerization of 1,4-diethynylbenzene on Cu(111)

The polymerization of 1,4-diethynylbenzene was studied on a Cu(111) surface using scanning tunneling microscopy (STM) under ultra-high vacuum conditions. Thermal activation yielded disordered covalent networks, where distinct basic structural motifs indicate different coupling reactions.

Self-organized and cu-coordinated surface linear polymerization

We demonstrate a controllable surface-coordinated linear polymerization of long-chain poly(phenylacetylenyl)s that are self-organized into a "circuit-board" pattern on a Cu(100) surface. Scanning tunneling microscopy/spectroscopy (STM/S) corroborated by ab initio calculations, reveals the atomistic details of the molecular structure, and provides a clear signature of electronic and vibrational properties of the poly(phenylacetylene)s chains. Notably, the polymerization reaction is confined epitaxially to the copper lattice, despite a large strain along the polymerized chain that subsequently renders it metallic. Polymerization and depolymerization reactions can be controlled locally at the nanoscale by using a charged metal tip. This control demonstrates the possibility of precisely accessing and controlling conjugated chain-growth polymerization at low temperature. This finding may lead to the bottom-up design and realization of sophisticated architectures for molecular nano-devices.