Topological Motifs in Cyanometallates: From Building Units to Three-Periodic Frameworks

This
review focuses on topological features of three-periodic (framework) p, d, and f metal cyano
complexes or cyanometallates, i.e. coordination compounds, where CN– ligands play the main structure-forming role. In addition,
molecular, one-periodic (chain), and two-periodic (layer) cyanometallates
are considered as possible building blocks of the three-periodic cyanometallates.
All cyanometallates are treated as systems of nodes (mononuclear,
polynuclear, or transitional metal cluster complexes) joined together
via CN-containing spacers. The most typical nodes and spacers as well
as methods of their connection are described and systematized. Particular
attention is paid to the overall structural motifs in the three-periodic
cyanometallates, especially to the relations between the local coordination
(coordination figure) of structural units and the entire framework
topology. The chemical factors are discussed that influence the cyanometallate
topological properties due to modification of nodes, spacers, or coordination
figures.