N-donor ligand driven CdII -based coordination polymers: Synthesis, structures and highly selective luminescence sensing for Fe3+ ions

Three Cd-II -based coordination polymers (CPs), formulated as [Cd-2(dnpdc)(3)(DMSO)(3)center dot 0.5H(2)O](n) (1), [Cd(dnpdc) (bpee)]( n) (2) and {Cd(dnpdc)(bimb).2H(2)O}(n) (3) have been successfully synthesized and structurally characterized. Compound 1 exhibits a 4-fold interpenetrated 3D diamond network based on dinuclear Cd-2 (OCO)(3) cluster. Compound 2 features 3D frameworks constructed from the 2D [Cd(dnpdc)](n) sheets pillared by 1D zig-zag shaped [Cd(bpee)](n) chains. In compound 3, the mononuclear Cd-II units are mixed connected by the dnpdc(2-) and bimb ligands, yielding the 6-fold interpenetrated 3D diamond network. The fluorescence measurements reveal that three compounds exhibit intense blue emission in the solid state. In particular, compound 3 exhibits highly selective chemical sensing for Fe3+ ions in aqueous solution.