Credit: © 2009 RSC

The unusual electronic properties of graphene have generated great interest in research into other two-dimensional materials. Furthermore, introducing pores with controlled size and distribution could be a way of tuning these electronic properties. Although 2D supramolecular assemblies have been prepared, the relatively weak interactions mean that the resulting materials have not been thermally or chemically stable enough to be useful.

Now, Marco Bieri and Roman Fasel of the Swiss Federal Laboratories for Materials Testing and Research and co-workers have reported1 the synthesis of the first 2D polymer with a controlled pore structure. Described as a 'porous graphene', it is assembled on a silver surface by polymerizing a macrocycle of six phenyl rings joined at their meta-positions, the silver promoting the coupling of the rings at 570 K to form a large sheet.

The resulting polymer could be annealed at 805 K and was stable up to the temperature at which the silver surface deformed. Its structure was examined using scanning tunnelling microscopy and found to resemble graphene with periodically 'missing' phenyl rings. The team hope this will open up a class of graphene-related functional materials with tunable electronic properties.