Abstract The cyanide group, CN-, is able to build up one- (1D), two- (2D), or three-dimensional (3D) frameworks by alternately linking one metal atom M to another metal atom M’. The M’—CN—M linkage is usually colinear; in some cases the M'—C—N or M—N—C bond, or both, bends to a certain extent. The deviation from colinearity is, however, not appreciable in comparison with the case of another ambidentate pseudohalogen group SCN-: the M’—SCN—M linkage is generally bent at the sulphur atom with an approximately tetrahedral angle. The sp hybridization character of the —C=N triple bond may contribute to the colinearity of the M’—CN—M linkage. One can easily depict the structure of a multi-dimensional framework comprised of the linear M'—CN—M linkages with the Mand M’ metal cations taking particular configurations of the respective coordination spheres: a ball- and-stick model is effective to depict the multi-dimensional host structure which can accommodate guest species.

Iwamoto, T. (1991). Inclusion compounds of multi-dimensional cyanometal complex hosts. Inclusion Compounds, 177–212.