3D-supramolecular copper(I) cyanide coordination polymers through hydrogen bonding

The reactions of K₃[Cu(CN)₄], 3-acetylpyridine (3-Acpy) or 4-acetylpyridine (4-Acpy) in the presence of Me₃SnCl in H₂O/acetonitrile media at room temperature afford the 3D-supramolecular coordination polymers (SCPs)_∞³[Cu₂CN(μ-CN)·(3-Acpy)₂] 1 and _∞³[Cu₂CN(μ-CN)·(4-Acpy)₂] 2. The structures of 1 and 2 consist of Cu₂CN building blocks which are connected by CN groups, forming 1D-zig-zag chains. Each chain is bonded to another chain by hydrogen bonding into a 2D-layer, which is further stacked in an interwoven mode by π–π stacking interactions and hydrogen bonds in 1 and 2, as well as Cu···Cu interactions in 1, to create supramolecular 3D-network structures. The high dimensional topologies of 1 and 2 result mainly from extensive hydrogen bonding and π–π stacking. The long wavelength absorption band at 400–420 nm in the electronic spectra of 1 and 2 is assigned to a CT from copper(I) to the Acpy ligand. Compound 2 exhibits strong luminescence at 485 and 527 nm, corresponding to MLCT and metal-centered transitions, respectively.