3-DIMENSIONAL FRAMEWORK STRUCTURES BUILT OF HEPTACYANOTRICADMATE(II) UNITS PROVIDING POLYHEDRAL CAVITIES FOR GUESTS - CLASSIFICATION OF THE ZEOLITE-LIKE STRUCTURES

A series of 17 inclusion compounds of composition [am.xG] [Cd-3(CN)(7)] (x = 1-2) has been obtained from the three-dimensional anionic [Cd-3(CN)(7)](-) host and guests of an onium cation am(+) and a neutral molecule G. The crystal structures of the inclusion compounds reveal a common feature for the host structures, i.e. an infinite chain with repeating -(CN)-Cd(t)-CN-Cd(o)-NC-Cd(t)- units, -(T-O-T)(n)-, Composed of tetrahedial Cd(t) and octahedral Cd(o) atoms linked by CN groups running along the mirror plane of the unit cell. The,three-dimensional hosts are constructed through. interchain connections between the mirror-planes by out-of-plane CN groups. Six types of structure have been classified according to differences in the mode of bending at both ends of the T-O-T and T-T entities in the chain and in the mode of interchain connections building up the three-dimensional framework structures.