Chiral Metal-Organic Frameworks

In the past two decades, metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) assembled from metal ions or clusters and organic linkers via metal-ligand coordination bonds have captivated significant scientific interest on account of their high crystallinity, exceptional porosity, and tunable pore size, high modularity, and diverse functionality. The opportunity to achieve functional porous materials by design with promising properties, unattainable for solid-state materials in general, distinguishes MOFs from other classes of materials, in particular, traditional porous materials such as activated carbon, silica, and zeolites, thereby leading to complementary properties. Scientists have conducted intense research in the production of chiral MOF (CMOF) materials for specific applications including but not limited to chiral recognition, separation, and catalysis since the discovery of the first functional CMOF (i.e., d- or l-POST-1). At present, CMOFs have become interdisciplinary between chirality chemistry, coordination chemistry, and material chemistry, which involve in many subjects including chemistry, physics, optics, medicine, pharmacology, biology, crystal engineering, environmental science, etc. In this review, we will systematically summarize the recent progress of CMOFs regarding design strategies, synthetic approaches, and cutting-edge applications. In particular, we will highlight the successful implementation of CMOFs in asymmetric catalysis, enantioselective separation, enantioselective recognition, and sensing. We envision that this review will provide readers a good understanding of CMOF chemistry and, more importantly, facilitate research endeavors for the rational design of multifunctional CMOFs and their industrial implementation.

Breathing 3D Frameworks with T-Shaped Connecting Ligand Exhibiting Solvent Induction, Metal Ions Effect and Luminescent Properties

To study the structural effects in three-dimensional porous coordination polymers, three novel flexible porous coordination polymers—[Cd2(bpdc)2](DMF)3(H2O) (1) and [M(bpdc)](DMF)(H2O) (M = Cd (2), Zn (3))—have been synthesized under solvothermal conditions with d10 block metal ions and T-shaped connecting ligand. Complexes 1–3 crystallize in different space groups, but they display the same ant network. The first two complexes can transform into each other via the alteration of guest, whereas complex 3 shows no structural change. The structural details reveal that the size of metal ions might be responsible for the transformation of porous frameworks. Furthermore, luminescent properties have been explored, and a guest-dependent shift of emission peaks was observed, suggesting potential application of the complexes as a probe.

Structural diversity and magnetic properties of three metal–organic frameworks assembled from a T-shaped linker

Three helical metal–organic frameworks were solvothermally synthesized by reacting a T-shaped linker, 2,2′-bipyridyl-5,5′-dicarboxylic acid ligand with transition metals, and the magnetic properties of the compounds were studied.

Syntheses, topological structures and properties of six metal–organic frameworks constructed from a flexible tetracarboxylate ligand

Six new metal–organic frameworks (MOFs), Co₂O(odip)(py)₂(DMSO)₂·3H₂O (1), Co₂(odip)(H₂O)(DMA)₂·2DMA (2), Co₄(odip)₂(H₂O)₄(DMSO)₂·5DMSO (3), [Zn₂(odip)(DMF)₂(H₂O)]·2DMF·2H₂O (4), Zn₂(odip)(H₂O) (5) and In(odip)·3ACN (6), have been synthesized from the 5,5′-oxydiisophthalic acid (H₄odip) ligand under solvothermal conditions.

Anion-templated assembly of three indium–organic frameworks with diverse topologies

Three novel In-MOFs with ung, crb and cbo networks based on the H₂bpydc ligand have been prepared under solvothermal conditions. Structural analyses reveal that these three compounds possess monomeric indium inorganic building units and they are obtained using different anion templates such as NO₃⁻, HCOO⁻ and Cl⁻.