Fluorinated MOF platform for selective removal and sensing of SO2 from flue gas and air.

Conventional SO2 scrubbing agents, namely calcium oxide and zeolites, are often used to remove SO2 using a strong or irreversible adsorption-based process. However, adsorbents capable of sensing and selectively capturing this toxic molecule in a reversible manner, with in-depth understanding of structure-property relationships, have been rarely explored. Here we report the selective removal and sensing of SO2 using recently unveiled fluorinated metal-organic frameworks (MOFs). Mixed gas adsorption experiments were performed at low concentrations ranging from 250 p.p.m. to 7% of SO2. Direct mixed gas column breakthrough and/or column desorption experiments revealed an unprecedented SO2 affinity for KAUST-7 (NbOFFIVE-1-Ni) and KAUST-8 (AlFFIVE-1-Ni) MOFs. Furthermore, MOF-coated quartz crystal microbalance transducers were used to develop sensors with the ability to detect SO2 at low concentrations ranging from 25 to 500 p.p.m.

A metal-organic framework-based splitter for separating propylene from propane.

The chemical industry is dependent on the olefin/paraffin separation, which is mainly accomplished by using energy-intensive processes. We report the use of reticular chemistry for the fabrication of a chemically stable fluorinated metal-organic framework (MOF) material (NbOFFIVE-1-Ni, also referred to as KAUST-7). The bridging of Ni(II)-pyrazine square-grid layers with (NbOF5)(2-) pillars afforded the construction of a three-dimensional MOF, enclosing a periodic array of fluoride anions in contracted square-shaped channels. The judiciously selected bulkier (NbOF5)(2-) caused the looked-for hindrance of the previously free-rotating pyrazine moieties, delimiting the pore system and dictating the pore aperture size and its maximum opening. The restricted MOF window resulted in the selective molecular exclusion of propane from propylene at atmospheric pressure, as evidenced through multiple cyclic mixed-gas adsorption and calorimetric studies.

Highly emissive Zn-Ln metal-organic frameworks with an unusual 3D inorganic subnetwork.

Mixed zinc-lanthanide (Zn-Ln) metal-organic frameworks (MOFs) based on the 3,5-pyrazoledicarboxylate ligand exhibit an unusual three-dimensional (3D) inorganic subnetwork and display highly efficient photoluminescence.

Poly[bis(µ-purin-9-ido-κ(2)N(7):N(9))zinc].

In the title compound, [Zn(C(5)H(3)N(4))(2)], the Zn(II) cation is in a nearly regular tetra-hedral coordination by purinate ligands. Each purinate ligand chelates two Zn(II) cations through two imidazole N atoms of the purinate anion ligand, leading to the formation of a three-dimensional network.

2,4,6-Triamino-1,3,5-triazine-1,3-diium aqua-penta-fluoridoaluminate.

The title compound, (C(3)H(8)N(6))[AlF(5)(H(2)O)], was obtained by solvothermal synthesis from the reaction of aluminium hydroxide, 1,3,5-triazine-2,4,6-triamine (melamine), aqueous HF and water at 323 K for 48 h. The structure consists of [AlF(5)(H(2)O)](2-) octa-hedra and diprotonated melaminium cations. Cohesion is ensured by a three-dimensional network of hydrogen bonds.