Crystal structure of a CuIIcomplex with a bridging ligand: poly[[pentakis[μ2-1,1′-(butane-1,4-diyl)bis(1H-imidazole)-κ2N3:N3′]dicopper(II)] tetranitrate tetrahydrate]

A novel two-dimensional→three-dimensional CuIIcoordination polymer, {[Cu2(C10H14N4)5](NO3)4·4H2O}n, based on the 1,1′-(butane-1,4-diyl)bis(1H-imidazole) (biim) ligand and containing one crystallographically unique CuIIatom, has been synthesized under hydrothermal conditions. The CuIIatom is coordinated by five N atoms from biim ligands, one of which has crystallographically imposed inversion symmetry, giving rise to a slightly distorted CuN5square-pyramidal geometry. The CuIIcations are linked by biim ligands to give a 44layer; the layers are further bridged by biim ligands, generating a double sheet with a thickness of 14.61 Å. The sheet features rhombic Cu4(biim)4windows built up from four CuIIcenters and four biim ligands with dimensions of 14.11 × 14.07 Å2. Each window of a layer is penetrated directly by the biim ligand of the adjacent net, giving a two-dimensional→three-dimensional entangled framework.