A diamond-type metal-organic framework based on nano-sized [Cu-8(mu(4)-I)(6)(PPh3)(4)](2+) clusters and cyanide-ion linkers: Design, structure and luminescent property

摘要

A three-dimensional (3D) metal-organic framework (MOF) [Cu-8(mu(4)-I)(6)(PPh3)(4)(CN)(2)]center dot H2O (1) has been designed and synthesized by building-block strategy. The crystal structure of 1 shows a diamond-type 3D network based on [Cu-8(mu(4)-I)(6)(PPh3)(4)](2+) clusters as subunits and cyanide-ion as linkers. The nano-sized cluster displays a tetra-capped adamantine structure to form a closed dodecahedron with four branches of PPh3. The clusters are further connected by cyanide ligands to form a 3D network with regular hexagonal tunnels, where water molecules reside. The framework shows good stability upon the removal of water, which has been confirmed by X-ray powder diffraction (XRD) analysis. 1 exhibits luminescent property at solid state, which may be attributed to the metal to ligand charge transfer (MLCT), halide to ligand charge transfer (XLCT) as well as ligand to ligand charge transfer (LLCT) by theoretical study.