Porous organic cage crystals: characterising the porous crystal surface.

The characterisation of porous crystalline solids often relies on single crystal X-ray diffraction, which does not give direct information about the surface of the material. Here, crystals of a porous organic cage, CC3-R, are investigated by atomic force microscopy and shown to possess two distinct gas-solid interfaces, proving that the bulk crystal structure is preserved at the porous crystal surface.