Synthesis of Isoreticular Zinc(II)-Phosphonocarboxylate Frameworks and Their Application in the Friedel-Crafts Benzylation Reaction

Discovery of two predictable (3,18)-connected topologies based on Wells-Dawson type cages for the design of porous metal phosphonocarboxylate frameworks

Highly connected molecular building blocks (MBBs) have been demonstrated to play a crucial role in reticular chemistry, particularly in predicting the topologies of metal-organic frameworks. Metal phosphonate clusters exhibit considerable advantages in constructing high-connectivity MBBs, owing to the multiple coordination modes offered by phosphonic ligands. Herein, four metal (M = CoII, MnII) phosphonocarboxylate frameworks (CoPCF-1,2 and MnPCF-1,2) were successfully prepared under solvothermal conditions by utilizing the phosphonocarboxylic ligand, 4'-phosphonobiphenyl-3,5-dicarboxylic acid (H4pbpdc), and their structural characterization was performed using single-crystal X-ray diffraction (SCXRD). The structures feature a duodenary nuclear M12(µ3-OH)2(CO2)12(PO3)6(DMF)6/(CH3COO)4.5 cluster, bearing resemblance to the well-known Wells-Dawson ion from polyoxometallate chemistry. It is the first time a Wells-Dawson type cage has served as an 18-connected molecular building block, forming two kinds of porous metal phosphonocarboxylate frameworks with novel (3,18)-connected gez and gea topologies. Their permanent porosities were confirmed through N2 adsorption studies. Notably, the MBB Co12 cluster-based CoPCF-1 shows a loss and recovery process of µ3-OH through single-crystal-to-single-crystal (SCSC) transformation. The magnetic properties of the four compounds exhibit antiferromagnetic behavior.

Increase of network hydrophilicity from sql to lvt supramolecular isomers of Cu-MOFs with the bifunctional 4-(3,5-dimethyl-1H-pyrazol-4-yl)benzoate linker

A slight difference in the H-bonding of the linker pyrazole-NH group changes the framework hydrophilicity drastically.

Mg1−xCoxLi2(3,5-pdcH)2(DMF)2 (x = 0, 0.285, 0.575, 1): a series of heterometallic coordination polymers doped with magnetic Co2+ ions

Presented is a series of Mg_1−xCo_xLi-HCPs with the turn-on effect of anti-ferromagnetic properties upon the doping of high-spin Co²⁺ ions at Mg²⁺ sites.

Three Zinc(II) Phosphonates: Syntheses, Structures and Sensing of Copper(II) Ions

Three zinc(II) phosphonocarboxylates, [Zn₃ (m-bpc)₂ (OH)]⋅(CH₃ )₂ NH₂ ⋅H₂ O (1), [Zn₂ (m-bpc)(m-Hbpc)(4,4'-bpy)]⋅(CH₃ )₂ NH₂ ⋅H₂ O (2) and [Zn₃ (m-bpc)₂ (4,4'-bpy)(CH₃ )₂ NH]⋅H₂ O (3) (m-H₃ bpc=3-phosphonobenzoic acid, 4,4'-bpy=4,4'-bipyridine), have been solvothermally synthesised to generate unique topologies, as characterised by single-crystal XRD. Compound 1 possesses a diamond topology, which has rarely been found among phosphonate-based metal-organic frameworks. Compound 2 shows a 2D layered structure with pendant m-Hbpc and 4, 4'-bpy ligands, in which the layers feature as a zeolite-like network. Compound 3 has a 3D sandwich pillared-layer framework with an interesting double-helix structure. Only 1 shows an adsorption capacity for CO₂ of 28.5 cm³  g^-1 at 273 K. Luminescence studies revealed that both 1 and 2 could be potential sensors to copper(II) ions.

Metal-organic frameworks: versatile heterogeneous catalysts for efficient catalytic organic transformations

Novel catalytic materials are highly demanded to perform a variety of catalytic organic reactions. MOFs combine the benefits of heterogeneous catalysis like easy post reaction separation, catalyst reusability, high stability and homogeneous catalysis such as high efficiency, selectivity, controllability and mild reaction conditions. The possible organization of active centers like metallic nodes, organic linkers, and their chemical synthetic functionalization on the nanoscale shows potential to build up MOFs particularly modified for catalytic challenges. In this review, we have summarized the recent research progress in heterogeneous catalysis by MOFs and their catalytic behavior in various organic reactions, highlighting the key features of MOFs as catalysts based on the active sites in the framework. Examples of their post functionalization, inclusion of active guest species and metal nanoparticles have been discussed. Finally, the use of MOFs as catalysts for asymmetric heterogeneous catalysis and stability of MOFs has been presented as separate sections.

A Copper-Based Metal-Organic Framework as an Efficient and Reusable Heterogeneous Catalyst for Ullmann and Goldberg Type C-N Coupling Reactions

A highly porous metal-organic framework (Cu-TDPAT), constructed from a paddle-wheel type dinuclear copper cluster and 2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine (H₆TDPAT), has been tested in Ullmann and Goldberg type C-N coupling reactions of a wide range of primary and secondary amines with halobenzenes, affording the corresponding N-arylation compounds in moderate to excellent yields. The Cu-TDPAT catalyst could be easily separated from the reaction mixtures by simple filtration, and could be reused at least five times without any significant degradation in catalytic activity.

A highly stable indium phosphonocarboxylate framework as a multifunctional sensor for Cu2+ and methylviologen ions

An indium phosphonocarboxylate framework (InPCF-1) with a novel 3,4,5-connected topology was synthesized, which serves as a selective and sensitive sensor for Cu²⁺ and MV²⁺ ions.