1,2-Cyclohexanedionedioxime as a useful co-ligand for fabrication of one-dimensional Zn(ii) and Cd(ii) coordination polymers with wheel-and-axle topology and luminescent propertiesElectronic supplementary information (ESI) available: IR spectra and X-ray crystallographic files in CIF format for the reported compounds 1-6. CCDC reference numbers 847362-847367, 860813 and 860814. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c2ce00020b

The combination of 1,2-cyclohexanedionedioxime (NioxH 2 ) and carboxylate-containing ligands resulted in Zn( ii ) or Cd( ii ) robust metal building blocks which being coupled with the flexible pyridine ligands fabricated five one-dimensional (1D) coordination polymers {[Cd(CHOO) 2 (NioxH 2 )(bpe)]·DMF} ∞ ( 1 ), [Cd(CHOO) 2 (NioxH 2 )(dps)] ∞ ( 2 ), [Zn(CH 3 COO) 2 (NioxH 2 )(dps)] ∞ ( 3 ), [Cd(CH 3 COO) 2 (NioxH 2 )(dps)] ∞ ( 4 ), and {[Zn(pyta) 2 (NioxH 2 )]·DMF} ∞ ( 5 ) (where bpe = 4,4′-bipyridine ethane, dps = 4,4′-dipyridylsulfide, Hpyta = (4-pyridylthio)acetic acid, DMF = N , N -dimethylformamide), whose crystal structures were determined by single crystal X-ray diffraction. The stability of compounds 1 and 5 to loss of DMF as a guest has been addressed experimentally, and the crystal-to-crystal transformation observed for 1 resulted in the guest free 1D polymer [Cd(CHOO) 2 (NioxH 2 )(bpe)] ∞ ( 1a ) which maintains its coordination network with the 10.3% unit cell volume contraction, while compound 5 remains unchangeable under the same conditions. Compounds 1 , 5 and the dioxime-free 1D polymer [Cd(pyta) 2 (H 2 O)] ∞ ( 6 ) display blue luminescence upon excitation with ultraviolet light. The emission intensity of the guest-loaded complex 1 is effectively reduced in comparison with the previously reported DMF free analogues [Zn(CH 3 COO) 2 (NioxH 2 )(bpe)(H 2 O)] ∞ and [Cd(CH 3 COO) 2 (bpe)(H 2 O)] ∞ . Six new coordination compounds reveal the 1,2-cyclohexanedionedioxime useful function for fabrication of porous 1D coordination polymers with wheel-and-axle geometry.