Syntheses, Crystal Structures, and Thermal Expansion Properties of Three-Dimensional Cyanide-Bridged Compounds Zn(4, 4′-bpy)(H2O)2M(CN)4 (4, 4′-bpy = 4, 4′-bipyridine; M = Ni, Pd, Pt)

. Three cyanide‐bridged compounds Zn(4, 4′‐bpy)(H2O)2M(CN)4 (4, 4′‐bpy = 4, 4′‐bipyridine; M = Ni (1), Pd (2), Pt (3)) were synthesized by self‐assembly of Zn2+ ions, pillar ligands 4, 4′‐bpy and [M(CN)4]2–. Single‐crystal X‐ray diffraction analysis revealed that compounds 1–3 are isostructural and belong to monoclinic space group C2/c. The zinc atom is located in a distorted octahedral arrangement, whereas the central nickel atom adopts square‐planar arrangement. The central Zn and Ni atoms are linked alternatingly through two cis cyanide groups, generating zigzag chains. The adjacent chains are further connected along two different directions by 4, 4′‐bpy ligands to form a three‐dimensional framework. Thermal expansion (TE) analyses of compounds 1–3 showed that both a and c axes are positive TE coefficients, compared to the near zero TE one along the b axis.