Chiral chemistry of metal-camphorate frameworks

Molecular tectonics: from a rigid achiral organic tecton to 3D chiral Co and Fe coordination networks

The combination of an achiral tetradentate coordinating tecton with achiral Co(SCN)₂ and Fe(SCN)₂ neutral complexes leads to the formation of isostructural crystals composed of 3D helical strands.

Chiral induction in a pcu-derived network from achiral precursors

The first chiral network derived from a classic pcu net has been rationally prepared from achiral precursors.

Two 2D multiresponsive luminescence coordination polymers for selective sensing of Fe3+, CrVI anions and TNP in aqueous medium

Zn(ii)/Cd(ii)-based 2D coordination polymers have been synthesized as luminescence sensors for the selective and reversible sensing of Fe³⁺, CrO₄²⁻, Cr₂O₇²⁻ and TNP in water.

Recent development trends for chiral stationary phases based on chitosan derivatives, cyclofructan derivatives and chiral porous materials in high performance liquid chromatography

The separation of enantiomers by chromatographic methods, such as gas chromatography, high-performance liquid chromatography and capillary electrochromatography, has become an increasingly significant challenge over the past few decades due to the demand of pharmaceutical, agrochemical, and food analysis. Among these chromatographic resolution methods, high-performance liquid chromatography based on chiral stationary phases has become the most popular and effective method used for the analytical and preparative separation of optically active compounds. This review mainly focuses on the recent development trends for novel chiral stationary phases based on chitosan derivatives, cyclofructan derivatives, and chiral porous materials that include metal-organic frameworks and covalent organic frameworks in high-performance liquid chromatography. The enantioseparation performance and chiral recognition mechanisms of these newly developed chiral selectors toward enantiomers are discussed in detail.

Metal-Organic Frameworks for Separation

Separation is an important industrial step with critical roles in the chemical, petrochemical, pharmaceutical, and nuclear industries, as well as in many other fields. Although much progress has been made, the development of better separation technologies, especially through the discovery of high-performance separation materials, continues to attract increasing interest due to concerns over factors such as efficiency, health and environmental impacts, and the cost of existing methods. Metal-organic frameworks (MOFs), a rapidly expanding family of crystalline porous materials, have shown great promise to address various separation challenges due to their well-defined pore size and unprecedented tunability in both composition and pore geometry. In the past decade, extensive research is performed on applications of MOF materials, including separation and capture of many gases and vapors, and liquid-phase separation involving both liquid mixtures and solutions. MOFs also bring new opportunities in enantioselective separation and are amenable to morphological control such as fabrication of membranes for enhanced separation outcomes. Here, some of the latest progress in the applications of MOFs for several key separation issues, with emphasis on newly synthesized MOF materials and the impact of their compositional and structural features on separation properties, are reviewed and highlighted.

Enhanced chiral recognition by γ-cyclodextrin-cucurbit[6]uril-cowheeled [4]pseudorotaxanes

Mixing γ-cyclodextrin (γ-CD), cucurbit[6]uril (CB[6]) and tetraammonium-bearing axles together led to a spontaneous formation of γ-CD-CB[6]-cowheeled [4]pseudorotaxanes. The well-defined unsymmetrical cavities thus formed enhance the binding affinity towards chiral amines by factors of several hundreds and show remarkably improved chiral discrimination.

Hydrogen bond-assisted homochiral lattice packing between inorganic helices built from heterometallic units

Two helical chains have been constructed using heterometallic {TiMn₂(μ₃-O)} clusters as building blocks, where hydrogen bonding plays a key role for the chirality transmission.

Synthetic strategies, diverse structures and tuneable properties of polyoxo-titanium clusters

A review of polyoxo-titanium clusters (PTCs), with an emphasis on synthetic methodologies, diverse structures, tuneable optical properties and potential applications.

Selective chiral symmetry breaking and luminescence sensing of a Zn(ii) metal–organic framework

The non-random handedness excess is observed in a chiral metal–organic framework [(CH₃)₂NH₂]₅[Zn_1.5(Zn₃O)(TATAT)₂]·9DMF·17H₂O (1, 1P ≫ 1M) without any chiral sources.

Helical carbon tubes derived from epitaxial Cu-MOF coating on textile for enhanced supercapacitor performance

A new helical carbon tube material has been prepared from epitaxial Cu-MOF coating on textile by calcination treatment.

Construction of unprecedented pillar-layered metal organic frameworks via a dual-ligand strategy for dye degradation

Presented here are two new pillar-layered MOFs based on different metal–carboxylate SBUs employed by mixing D-H₂Cam and OH-bim ligands. The Zn/Co mixed compound 2 exhibits an adjustable Zn/Co ratio, which reversibly results in an adjustable photocatalytical property of dye degradation.

Color tuning and white light emission by codoping in isostructural homochiral lanthanide metal–organic frameworks

Pure white-light emission and fluent light-emitting color change can be facilely obtained by codoping isostructural homochiral lanthanide metal–organic frameworks.

Chiral metal–organic frameworks constructed from four-fold helical chain SBUs for enantioselective recognition of α-hydroxy/amino acids

Three chiral 3D metal–carboxylate frameworks have been successfully synthesized, featuring four-fold helical metal chains as SBUs. Co-MOFs could recognize enantio-selectively α-hydroxy/amino acids by the change of CD signals.

Syntheses, structures, luminescence and magnetic properties of seven isomorphous metal–organic frameworks based on 2,7-bis(4-benzoic acid)-N-(4-benzoic acid)carbazole

Seven isomorphous lanthanide metal–organic frameworks with special luminescence and magnetic properties are synthesized and characterized.

A triphenylamine-functionalized luminescent sensor for efficient p-nitroaniline detection

The combination of π-conjugated fluorophores within a hybrid system gives rise to a triphenylamine-functionalized material [Zn(bpba)(NO₃)] (1) (Hbpba = 4-(bis(4-(pyridin-4-yl)phenyl)amino)benzoic acid).

Insight into the epitaxial encapsulation of Pd catalysts in an oriented metalloporphyrin network thin film for tandem catalysis

A palladium catalyst (Pd-Cs) encapsulated metalloporphyrin network PIZA-1 thin film with bifunctional properties has been developed through a modified epitaxial layer-by-layer encapsulation approach. Combining the oxidation activity of Pd-Cs and the acetalization activity of the Lewis acidic sites in the PIZA-1 thin film, this bifunctional catalyst of the Pd-Cs@PIZA-1 thin film exhibits a good catalytic activity in a one-pot tandem oxidation-acetalization reaction. Furthermore, the surface components can be controlled by ending the top layer with different precursors in the thin film preparation procedures. The catalytic performances of these thin films with different surface composites were studied under the same conditions, which showed different reaction conversions. The result revealed that the surface component can influence the catalytic performance of the thin films. This epitaxial encapsulation offers a good understanding of the tandem catalysis for thin film materials and provides useful guidance to develop new thin film materials with catalytic properties.

Epitaxial Growth of Oriented Metalloporphyrin Network Thin Film for Improved Selectivity of Volatile Organic Compounds

This study reports an oriented and homogenous cobalt-metalloporphyrin network (PIZA-1) thin film prepared by liquid phase epitaxial (LPE) method. The thickness of the obtained thin films can be well controlled, and their photocurrent properties can also be tuned by LPE cycles or the introduction of conductive guest molecules (tetracyanoquinodimethane and C₆₀ ) into the PIZA-1 pores. The study of quartz crystal microbalance adsorption confirms that the PIZA-1 thin film with [110]-orientation presents much higher selectivity of benzene over toluene and p-xylene than that of the PIZA-1 powder with mixed orientations. These results reveal that the selective adsorption of volatile organic compounds highly depends on the growth orientations of porphyrin-based metal-organic framework thin films. Furthermore, the work will provide a new perspective for developing important semiconductive sensing materials with improved selectivity of guest compounds.