Guest Molecules Containing Rich-electron Group Incorporation into Zn-based MOF for the Enhancement of Iodine Uptake.

Radioactive iodine capture is a major concern for nuclear power generation and environmental protection. Many metal-organic frameworks (MOFs) have been designed and synthesized to adsorb iodine from vapor or solution, but most of them exhibited unsatisfactory iodine uptake performance because of the insufficiency of adsorption sites. Herein, we chose 1-vinyl-3-ethylimidazolium bromide (VIMB) and 1,2-diaminocyclohexane (DACH) with rich-electron group as guest molecules, respectively, and encapsulated them into a three-dimensional Zn-based MOF Zn-BINOL with large 1D channel (BINOL=(R)-2,2'-diethoxy-1,1'-binaphthyl-4,4',6,6'-tetrabenzoate), as a result, two efficient iodine adsorbents VIMB@Zn-BINOL and DACH@Zn-BINOL were obtained.

Metal-Organic Frameworks Based on Multicenter-Bonded [M ] (M=Mn, Zn) Clusters with Cubic Aromaticity.

A new concept for constructing metal-organic frameworks (MOFs) based on multicenter-bonded [M ] (M=Mn, Zn) clusters with cubic aromaticity is discussed. In principle, intermolecular/intramolecular hydrogen-bonding, π-π stacking, coordinated covalent bonding and ionic bonding usually account for the structures of MOFs, and multicentered bonds generally exist in cation, anion, neutral and zwitterionic radicals, while rarely appear in MOFs. Meanwhile, aromaticity became one of the most vexing yet fascinating key concepts in chemistry since the proposition of the structure of benzene molecule in 1865.

Stable Zn -Containing MOFs with Large [Zn ] Nanocages from Assembly of Zn Ions and Aromatic [Zn ] Clusters.

Two unique Zn -containing MOFs {[Zn Zn (H O) (HL) ](OH) ⋅13 H O} (x=6, 1; x=2, 2) (HL=tetrazole monoanion) with high-nuclearity Zn-cages were prepared successfully. These Zn-cages are constructed from [Zn ] clusters with multi-centered Zn -Zn bonds and Zn ions. [Zn ] clusters in 1 and 2 display O and D symmetry, respectively.

Metal-Organic Frameworks (MOFs) of a Cubic Metal Cluster with Multicentered Mn(I)-Mn(I) Bonds.

MOFs with both multicentered metal-metal bonds and low-oxidation-state (LOS) metal ions have been underexplored hitherto. Here we report the first cubic [Mn(I) 8 ] cluster-based MOF (1) with multicentered Mn(I)-Mn(I) bonds and +1 oxidation state of manganese (Mn(I) or Mn(I)), as is supported by single-crystal structure determination, XPS analyses, and quantum chemical studies. Compound 1 possesses the shortest Mn(I)-Mn(I) bond of 2.

First tetrazole-bridged d-f heterometallic MOFs with a large magnetic entropy change.

A novel 3D tetrazole-bridged 3d-4f heterometallic MOF {(H3O)3[Gd3Mn2(Trz)4]·12H2O}n (1) with a hexanuclear [Gd6] cluster was obtained via in situ [2+3] cycloaddition reaction and structurally characterized, possessing good solvent and thermal stabilities, as well as a large magnetic entropy change -ΔS(m) = 40.3 J kg(-1) K(-1) for ΔH = 7 T at 2.0 K.

Lanthanide organic framework as a regenerable luminescent probe for Fe(3+).

A unique three-dimensional Tb-BTB framework (1) with two types of one-dimensional channels was obtained and structurally characterized, exhibiting high thermal stability. Luminescent investigations reveal that 1 can detect Fe(3+) with relatively high sensitivity and selectivity. Importantly, 1 as the luminescent probe of Fe(3+) can be simply and quickly regenerated, which represents a rare example in reported luminescent sensors of Fe(3+).

Heterometal-organic frameworks as highly sensitive and highly selective luminescent probes to detect I⁻ ions in aqueous solutions.

Two cationic heterometal-organic frameworks (Eu-Zn (1·NO₃⁻) and Tb-Zn (2·NO₃⁻)) with NO3(-) counter-anions in the channels are structurally and luminously characterized. Both of them can serve as highly sensitive and highly selective luminescent probes for detecting I(-) ions in aqueous solutions. In particular, 2·NO₃⁻ can selectively and reversibly detect I(-) with a fast response time of just 10 s and an extremely low detection limit of 0.