Synthesis, structure and luminescent properties of Cu(I)-cyanide frameworks based on bent dipyridyl-oxadiazole ligands

Hydrothermal reaction of CuCN with 2,5-bis(3-pyridyl)-1,3,4-oxadiazole (3-bpo) affords a wave-like infinite chain coordination polymer [Cu2(CN)2(3-bpo)]n (1). Replacement of 3-bpo by its isomer 2,5-bis(4-pyridyl)-1,3,4-oxadiazole (4-bpo) could yields polymer [Cu(CN)(4-bpo)]n (2). In the complex 1, the bent 3-bpo ligand adopts bidentate chelating mode binds with the Cu(I)-cyanide chain to form 16-membered macrocyclic structure. The complex 2 exhibits a layered metal–organic framework, in which exo-bidentate 4-bpo ligand connects the Cu(I)-cyanide chains to form 2-D rectangle grid. Both of these Cu(I) complexes are thermal stable under 200 °C and release 3-bpo or 4-bpo ligand in 200–360 °C. Luminescent study reveals that 1 has green-light emission, while 2 has blue-light emission.