Cation control on the crystal organization of hexanuclear carbonyl cluster anions

Researchers used empirical packing potential energy measurements, van der Waals volume investigation and computer graphics to study the crystal structures of 28 hexanuclear carbonyl cluster anions, and to study the association between shape, size and charge of the component ions and the development of selective agregates (piles, 'snakes', layers) in the crystal lattice. In the case of large organic cations, the packing type is basically that of molecular mixed crystals, but small cations move toward monodimensional aggregation of the anions.