Influence of the Synthesis and Crystallization Processes on the Cation Distribution in a Series of Multivariate Rare-Earth Metal-Organic Frameworks and Their Magnetic Characterization

The incorporation of multiple metal atoms in multivariate metal-organic frameworks is typically carried out through a one-pot synthesis procedure that involves the simultaneous reaction of the selected elements with the organic linkers. In order to attain control over the distribution of the elements and to be able to produce materials with controllable metal combinations, it is required to understand the synthetic and crystallization processes. In this work, we have completed a study with the RPF-4 MOF family, which is made of various rare-earth elements, to investigate and determine how the different initial combinations of metal cations result in different atomic distributions in the obtained materials. Thus, we have found that for equimolar combinations involving lanthanum and another rare-earth element, such as ytterbium, gadolinium, or dysprosium, a compositional segregation takes place in the products, resulting in crystals with different compositions. On the contrary, binary combinations of ytterbium, gadolinium, erbium, and dysprosium result in homogeneous distributions. This dissimilar behavior is ascribed to differences in the crystallization pathways through which the MOF is formed. Along with the synthetic and crystallization study and considering the structural features of this MOF family, we also disclose here a comprehensive characterization of the magnetic properties of the compounds and the heat capacity behavior under different external magnetic fields.

Designed assembly of heterometallic zeolite-like framework materials from two different supertetrahedral metal clusters

This work demonstrates a feasible strategy for the synthesis of new zeolite-like framework materials. With the strategy of using two different supertetrahedral clusters as secondary building units, two new heterometallic zeolite-like frameworks with isomeric structures but tunable topologies were first made. Besides, the porous nature and the proton conduction performance of the new materials were further studied.

Metalloligand-based Coordination Polymer Embedding the Nitrosyl Ruthenium Complex for Photoactive Materials with Bounded Nitric Oxide

The stability of photoactivated isonitrosyl state was boosted by confining a pre-designed bicarboxylate ligand with a ruthenium nitrosyl fragment in a 2D metal-organic framework. The novel Zn/Ru-based MOF, {Zn[RuNO(H2O)(inic)2(OH)2]2}∙12H2O (inic...

Reversible Structural Transformation of CuI-TbIII Heterometallic MOFs with Highly Efficient Detection Capability toward Penicillin

A Cu^I-Tb^III heterometallic MOF, namely 1·DMF, was obtained via a coordination assembly process of isonicotinic acid with Cu^I and Tb^III. 1·DMF can be switched to 1·MeOH in methanol with a luminescent emission response. Meanwhile, 1·MeOH exhibits a reversible single-crystal transformation to 1·DMF after immersion in DMF. Both MOFs have superior physicochemical stability. The 1·DMF-based biosensor has a remarkable sensing performance toward penicillin.

Coordination-driven assembly of a 3d-4f heterometallic organic framework with 1D Cu4I4 and Eu-based chains: syntheses, structures and various properties

A three-dimensional porous 3d-4f heterometallic organic framework, namely, {[Eu3(Cu4I4)3(INA)9(DMF)4]·3DMF}n (YNU-2), was successfully prepared under solvothermal conditions. There are two different one-dimensional metal chains in the structure, namely, Cu4I4 and EuIII-based chains, resulting in an excellent stability of the prepared sample. A N2 sorption isotherm at 77 K revealed that the activated sample exhibits a Brunauer-Emmett-Teller surface area of 371 m2 g-1, while, YNU-2 can adsorb obviously higher CO2 amounts than CH4 at 273 K and 298 K under 1 atm because of the stronger interaction force between CO2 and the porous skeleton. Furthermore, YNU-2 is highly efficient heterogeneous catalyst for chemical fixation of the CO2 and epoxides into cyclic carbonates with a preferable recyclability. Taking into account its excellent stability, the prepared sample can be used to construct an electrochemical adapter sensor for detecting cocaine with a detection limit of 0.27 pg mL-1 in the wide range of 0.001-0.5 ng mL-1.

Construction of high-nuclear 4p–4f heterometallic {Ln11Ge12} cluster-organic frameworks with high-sensitivity luminescence sensing of Fe3+ in aqueous solution

The [Pr₁₁Ge₁₂] 4p–4f cluster-organic framework shows highly selective and sensitive sensing of Fe³⁺ in aqueous solution.

The incorporation of heterovalent copper-oxo and copper-halide clusters for the fabrication of three porous cluster organic frameworks: syntheses, structures and iodine adsorption/release study

Three porous cluster organic frameworks constructed from the paddle-wheel Cu₂(CO₂)₄ and cubane-like Cu₄I₄ clusters have been synthesized and characterized. Interestingly, compound 2 shows moderate gas uptake ability and I₂ adsorption/release feature.

A heterometallic D–A hybrid heterostructural framework with enhanced visible-light photocatalytic properties

A heterometallic D–A hybrid heterostructural framework from the ternary combination of CuI, lanthanide cations and viologen tectons exhibited enhanced photocatalytic activities for degradation of organic dyes.