Self-Assembly of Organic–Inorganic Hybrid Materials Constructed from Eight-Connected Coordination Polymer Hosts with Nanotube Channels and Polyoxometalate Guests As Templates

Two polyoxometalate-templated organic–inorganic hybrid porous frameworks, namely, [Cu2(H2O)2(bpp)2Cl][PM12O40]·∼20H2O (for 1, M = W; for 2, M = Mo; bpp = 1,3-bis(4-pyridyl)propane), were self-assembly obtained and structurally determined by elemental analyses, inductively coupled plasma analyses, infrared spectroscopy, and single-crystal X-ray diffraction analyses. Single-crystal X-ray analysis of these crystals revealed that both of the structures are constructed from eight-connected three-dimensional coordination polymer hosts [Cu2(H2O)2(bpp)2Cl]n3n+ and ball-shaped Keggin-type guests [PM12O40]n3n− as templates. The polymer hosts resulted from a bcc-type framework with nanotubes, and the nanotubes can be regarded as a tetra-stranded helix structure. Furthermore, compounds 1 and 2 exhibit photoluminescent properties at ambient temperature, and the compound 2 bulk-modified carbon paste electrode (2-CPE) displays good electrocatalytic activity toward the reduction of nitrite.