On‐Surface Assembly of Hydrogen‐ and Halogen‐Bonded Supramolecular Graphyne‐Like Networks

Abstract

Demonstrated here is asupramolecular approach to fabricate highly ordered monolayered hydrogen-and halogenbonded graphyne-like two-dimensional (2D) materials from triethynyltriazine derivatives on Au(111) and Ag(111). The 2D networks are stabilized by N···H À C(sp) bonds and N···Br À C(sp) bonds to the triazine core.The structural properties and the binding energies of the supramolecular graphynes have been investigated by scanning tunneling microscopyincombination with density-functional theory calculations.I ti sr evealed that the N···BrÀC(sp) bonds lead to significantly stronger bonded networks compared to the hydrogen-bonded networks.Asystematic analysis of the binding energies of triethynyltriazine and triethynylbenzene derivatives further demonstrates that the X 3 -synthon, which is commonly observed for bromobenzene derivatives,i sw eaker than the X 6synthon for our bromotriethynyl derivatives.

Real-space Imaging of the Multiple Halogen Bonds by Ultrahigh-resolution Scanning Probe Microscopy

“…The calculated results suggests that charge transfer between Br-N and Br-H atoms also play an important role, in line with IUPAC recommendations and literature reports. 3,15,41 We infer that the electron density between Br-N and Br-H atoms may also contribute to the bright lines feature observed at nc-AFM images in Figure 2b and 2e, and the higher intensity of electron density between Br-H atoms than that between Br-N atoms results in a brighter line of Br-H bond than that of Br-N bond shown at nc-AFM images.…”

“…The chemical bond is of central interest in the chemistry discipline, and it plays an important role in the construction of both matter and life. In particular, non-covalent bonds are the fundamental basis of supramolecular self-assembly, 1 including hydrogen bonds, 2 halogen bonds, 3 coordination bonds, 4,5 dipole-dipole interactions 6 and so on. [7][8][9] The halogen bond has recently attracted much interest, 10 while the hydrogen bond has been the most studied intermolecular interaction in the past.…”

Realizing Two-Dimensional Spin Arrays on Surfaces via Halogen-Bonding Molecular Self-Assembly

“…DFT-optimized model in Figure 4c shows that six Br atoms form a hexagonal-shaped structure with the bond angle (∂3) of ~119 o and Br-Br distance (d3) of ~3.6 Å. Type-3 halogen bond has been theoretically predicted, 55 and it was recently demonstrated by Maier et al in experiment. 45 We noted that the types of halogen bonds are diverse, which can be employed to realize variable molecular self-assembled structures and thus adjusting the lateral distance of two molecular spins. Here we recorded three different distances between two molecular spins: 13.6 Å, 21.3 Å and 23.1 Å, respectively.…”

“…[36][37][38][39][40][41][42] In particular, by employing high-resolution surface characterization techniques, halogen bonds have recently been studied and show great promise in mediating highly-ordered supramolecular arrays on surface. [43][44][45][46] In this work, a bromine-terminated perchlorotriphenymethyl radical (3Br-PTM) with net carbon spin was synthesized and thermally-deposited to achieve two-dimensional ordered spin arrays on an insulating bromine monolayer on Au(111). Halogen bonds play an important role in regulating the supramolecular spin arrays formation on surface.…”

Helical Conformation Tunability via Hydrogen Bonding in Supramolecular Frameworks

“…[12][13][14][15][16][17] Understanding how hydrogen bonding influences the molecular self-assembly is a key step to realize the controllable fabrication and manipulation of functionalized molecules into complex architectures and is crucial for the potential applications such as molecular electronic devices. [18][19][20] With the development of scanning-probe microscopy techniques, high-resolution imaging provides the possibility to characterize the molecular structures directly, 21,22 which delivers an appealing hotbed for investigating the role of hydrogen bonds in molecular self-assembly. Here, we used specifically designed molecules with dynamical molecular conformation as building blocks for self-assembly fabrication, which furnishes a model system for investigating the rich relationships between hydrogen bonding and molecular selfassembly, including the emergent tunable molecular conformation in the molecular framework.…”