The Node-and-Spacer Paradigm

SCHEME 3. (a) Inorganic ligands, (b) Neutral organic ligands, (c) Anionic organic 

Cd(CN)2, is isomorphous. To prevent the interpenetration, relatively large species must be hosted into the diamondoid network. Indeed, the mixed metal complex NMe4[Cu Zn CN)4] shows no interpenetration because the tetra-methylammonium cations, whose size fits to that of the adamantane-like cavity, occupy half of these cavities (both Cu and Zn ions are tetracoordinated). The interpenetration of neutral M(CN)2 nets (M = Zn, Cd) can be hindered by hosting neutral molecules, structurally similar to NMe4. The solution of this problem is obvious and elegant The crystallization of Cd(CN)2 in the presence of Me4C leads to a single diamond-like net.  

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