Crystal Engineering of Novel Materials Composed of Infinite Two- and Three-Dimensional Frameworks

A general approach to the construction of new types of infinite frameworks based on a number of simple structural prototypes is described. Whereas Cu(4,4′,4″,4‴-tetracyanotetraphenylmethane)BF4.xC6H5NO2 contains a single diamond-like framework which generates huge intra-framework spaces filled with essentially fluid nitrobenzene, Cu(1,4-dicyanobenzene)2BF4 contains five independent diamond-like frameworks which interpenetrate leaving no space for solvent. Simple mixing of the components NMe4+, Zn2+, Cu+ and CN- leads to the spontaneous assembly of the intended diamond-related array of composition [NMe4][ZnCu(CN)4]. A new simple structural prototype is provided by Cd(CN)2.2/3H2O.tBuOH which contains an infinite honeycomb-like framework consisting of interconnected square planar and tetrahedral centres in 1:2 proportions; Cd(CN)2.1/3hexamethylenetetramine has a geometrically very different framework structure which nevertheless has an identical connectivity or topology. A number of metal-4,4'-bipyridine derivatives consist of two perpendicular stacks of 2D square grid sheets which interpenetrate to give an unprecedented 3D concatenation. M[C(CN)3]2 crystals (M=Zn, Cu, Cd, Ni, Co, Mn) consist of two independent, interpenetrating rutile-like frameworks. A new type of 3D net is produced by interconnecting 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine palladium building blocks via Cd centres. A PtS-related framework can be deliberately constructed by interconnecting square planar Pt(CN)42- building blocks by tetrahedral CuI centres.