2D constraint modifies packing behaviour: a halobenzene monolayer with X halogen-bonding motif.

Using a combination of X-ray diffraction and simulation techniques, we are able to identify a crystalline monolayer of 1,3,5-triiodotrifluorobenzene formed on graphite. The monolayer is found to exhibit an incommensurate hexagonal unit cell with a lattice parameter of 9.28(7) Å, exhibiting a trigonal arrangement of iodine atoms not found in the bulk structure.

Halogen Bonding in Bicomponent Monolayers: Self-Assembly of a Homologous Series of Iodinated Perfluoroalkanes with Bipyridine.

A homologous series of halogen bonding monolayers based on terminally iodinated perfluoroalkanes and 4,4'-bipyridine have been observed on a graphitic surface and noninvasively probed using powder X-ray diffraction. An excellent agreement is observed between the X-ray structures and density functional theory calculations with dispersion force corrections. Theoretical analysis of the binding energies of the structures indicate that these halogen bonds are strong (25 kJ mol), indicating that the layers are highly stable.

C-H … N hydrogen bonding in an overlayer of s-triazine physisorbed on a graphite surface.

The structure of a crystalline monolayer of 1,3,5-triazine has been characterised using X-ray diffraction. The monolayer is found to exhibit a hexagonal unit cell with a lattice parameter of 6.161(5) Å, indicating the formation of C-H … N hydrogen bonds.