A new three-dimensional coordination polymer, {[Co(μ₂-H₂O)(bdc)(H₂O)(dmf)]·0.5H₂O}_n (1), was obtained as a by-product in the synthesis of the laminar solid {[Co₂(μ₂-H₂O)(bdc)₂(S-nia)₂(H₂O)(dmf)]·(dmf)₂·H₂O}_n (2) (where H₂bdc = 1,4-benzenedicarboxylic acid, S-nia = thionicotinamide, dmf = N,N′-dimethylformamide). The three-dimensional network in 1 is organized of Co(II) atoms in O₆ octahedral coordination environments separated by μ₂-water molecules in coordination chains. The bdc²⁻ anions coordinate in monodentate mode and also act as bridging ligands that extend the structure in two other directions. The coordination cores of two crystallographically different Co(II) atoms are completed by either two dmf or two water molecules. The rhombohedral open channels contain water molecules. The evacuation of solvents from 1 occurs as a single crystal to single crystal transformation and results in MOF-71, [Co(bdc)(dmf)]_n, whose structure was confirmed by single crystal X-ray diffraction.

Ten Zn(II) and Cd(II) metal–organic materials were synthesized and studied by the X-ray method. Among these 10 structures, two represent binuclear clusters, and two are one-dimensional (1D) coordination polymers, while five are laminar two-dimensional (2D) solids and one is the three-dimensional (3D) framework. The investigation has been aimed at rational design of coordination polymers decorated by oxime ligands to increase the accessible adsorption area in these newly synthesized solids. The ligands used include three aliphatic dicarboxylic acids, HOOC-(CH₂)_n-COOH [n = 1, 2, 4 corresponding to malonic (H₂mal), succinic (H₂suc), and adipic (H₂adi) acids], and three neutral oxime ligands [pyridine-2-aldoxime (2-pyao), pyridine-4-aldoxime (4-pyao), and 1,2-cyclohexanedionedioxime (Niox)]. These novel hybrid solids with the compositions [Zn₂(suc)₂(2-pyao)₄]·2H₂O 1, [Cd₂(suc)(2-pyao)₄(H₂O)₂][BF₄]₂ 2, [Cd(suc)(2-pyao)₂]_n 3, [Zn(mal)(4-pyao)(H₂O)]_n 4, [Cd(mal)(4-pyao)(H₂O)]_n 5, [Zn(suc)(4-pyao)]_n 6, [Zn(adi)(4-pyao)₂]_n 7, {[Cd(adi)(4-pyao)₂]·dmf}_n 8, [Zn(adi)(Niox)]_n9, and [Cd(adi)(Niox)]_n 10 [dmf – N,N′-dimethylformamide] demonstrate a variable class of coordination supramolecular architectures dictated by the distinctions in the metals’ and oxime ligands’ coordination capacities and preferences, and length and flexibility of the dicarboxylic linkers. The discrete aggregates 1 and 2 differ by the components’ ratio and conformation of the bridging succinate anion; compounds 3 and 7 are 1D arrays, and compounds 4, 5, 6, 8, and 9 represent 2D layers of different topologies. Compound 10 is a 3D grid afforded by the concerted contribution of the longest in this series adipate anion, and the bigger atomic radius Cd(II) vs. Zn(II). The adsorptive properties of 7 and 9 are reported. For the laminar solid 9, the quantum chemical simulations of the adsorption capacity are in line with the experimental results. All new materials reveal dual green-blue wavelength emission in the solid state.