Construction of 2D zinc(II) MOFs with tricarboxylate and N-donor mixed ligands for multiresponsive luminescence sensors and CO2 adsorption

The solvothermal reactions of ZnCl2·6H2O, benzene-1,3,5-tribenzoic acid (H3btb), and N-heterocyclic ancillary imidazole (Im) or aminopyrimidine (a mp) ligands led to the creation of two-dimensional (2D) zinc(II) based metal-organic frameworks (MOFs), (Me2NH2)2[Zn2(btb)2(Im)2]·2DMF·3MeOH (1) and (Me2NH2)2[Zn2(btb)2(amp)]·H2O·2DMF·MeOH (2). The btb3- ligands in 1 and 2 form an anionic 2D layered structure with a (63) honeycomb (hcb) topology by linking to Zn(II) centres through their carboxylate groups. The incorporation of N-heterocyclic auxiliary ligands Im and amp into the hcb nets resulted in the formation of a 2D hydrogen-bonded and covalently pillared bilayer structure featuring two-fold interpenetrating networks. Each of these networks consists of small channels that are occupied by Me2NH2 cations and solvent molecules. Both 1 and 2 emit blue luminescence emissions in the solid state at room temperature and exhibit a great selectivity and sensitivity for the detection of acetone and multiple heavy metal ions including Hg2+, Cu2+, Fe2+, Pb2+, Cr3+, and Fe3+ ions. At 1 bar, activated 1 and 2 demonstrate moderate capacities for adsorbing CO2 at room temperature, with a preference for CO2 over N2. Notably, at higher pressures (up to 20 bar), their activated samples 1 and 2 show a temperature-dependent enhancement of CO2 uptake while retaining good stability.

Structural diversity, luminescence and photocatalytic properties of six coordination polymers based on designed bifunctional 2-(imidazol-1-yl)terephthalic acid

Six CPs, based on 2-(imidazol-1-yl)terephthalic acid, have been prepared and characterized.

Self-assembly, crystal structures and properties of metal–3,4,5-tris(carboxymethoxy)benzoic acid frameworks based on polynuclear metal-hydroxyl clusters (M = Zn, Co)

Three new inorganic–organic frameworks based on 3,4,5-tris(carboxymethoxy)benzoic acid and polynuclear metal-hydroxyl clusters were assembled. Photoluminescent and magnetic properties are investigated.

Discrete and polymeric complexes formed from cobalt(ii), 4,4′-bipyridine and 2-sulfoterephthalate: synthetic, crystallographic and magnetic studies

Five discrete and polymeric complexes have been prepared and characterised from the reaction of different ratios of Co(ii), 4,4′-bipyridine and 2-sulfoterephthalate.

Structural versatility and luminescent properties in d(10) metal ion polymers with 1,4-naphthalenedicarboxylate acid and 4,4'-dipyridyl N,N'-dioxide

Hydrothermal reactions of d(10) metal ions (Cd(2+) and Zn(2+)) with 1,4-naphthalenedicarboxylate acid (1,4-H2NDC) and 4,4'-dipyridyl N,N'-dioxide (4,4'-dpdo) form two three-dimensional grid-like coordination polymers [Cd2(1,4-NDC)2(4,4'-dpdo)]·H2O 1 and [Zn4(μ3-OH)2(1,4-NDC)3(H2O)2](4,4'-dpdo)·2H2O 2. Both coordination polymers were characterized by single crystal X-ray diffraction, IR spectroscopy, XRPD, thermogravimetric and elemental analyses. Polymer 1 exhibits rare alternating arranged 1,4-NDC(2)(-) and 4,4'-dpdo spacers between adjacent 1D zigzag chains containing Cd-octahedral coordination geometries. Polymer 2 is constructed from infrequent chair-like [Zn4(μ3-OH)2](6+) inorganic SBUs with four- and six-coordination geometries and only 1,4-NDC(2)(-) as "single-bridge" and "double-bridges" to form a 3D framework. Both polymers give strong luminescent emissions in the solid state at room temperature.