Cover illustration: A perspective view of bis(6-cis-2,4,6,8,10,12,14,16-octamethylcyclooctasiloxane-2,4,6,8,10,12,14,16-octolato)octakis[(dimethylformamide)copper(II)] dimethylformamide pyrazine solvate, showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. See Zherlitsyna, Auner & Bolte [Acta Cryst. (2006), C62, m199-m200].
The crystal structure of Cu3(CN)4(NH3)2Hg(CN)2 is a threefold-interpenetrating structure of three-dimensional frameworks, which are formed from two-dimensional network CuI/CuII–cyanide complexes, Cu3(CN)4(NH3)2, connected by rod-like Hg(CN)2 groups.