Nanoporous molecular crystals

Abstract

Nanoporous Molecular Crystals (NMCs) are nanoporous materials composed of discrete molecules between which there are only non-covalent interactions—i.e. they do not possess an extended framework composed of covalent or coordination bonds. They are formed from removing guest molecules from inclusion compounds (ICs) a process that for most ICs usually results in the collapse of the open structure of the crystals but in the case of NMCs the packing of the host molecules is retained and nanoporosity obtained. In recent years a number of NMCs have been confirmed by the technique of gas adsorption and these materials are surveyed in this feature article. In addition, the reasons for stability of these crystals are discussed. It is the author's belief that many more ICs, the structures of which are readily obtainable from the Cambridge Structural Database (CSD), may act as precursors to NMCs.