In spite of their great promise for enantioselective processes due to the rich host-guest chemistry, it remains a challenge construct covalent organic frameworks (COFs) with chiral three-dimensional (3D) structures. Here we report bottom-up synthesis first example 3D COFs by imine condensation an enantiopure 2-fold symmetric TADDOL-derived tetraaldehyde tetrahedral tetra(4-anilyl)methane. After postsynthetic oxidation linkages, framework is transformed into amide-linked COF retention...

Covalent organic frameworks (COFs) have emerged as a novel platform for material design and functional explorations, but it remains challenge to synthetically functionalize targeted structures task-specific applications. Optically pure 1,1′-bi-2-naphthol (BINOL) is one of the most important sources chirality synthesis materials science, has not yet been used in construction COFs enantioselective processes. Here, by elaborately designing choosing an enantiopure BINOL-based linear dialdehyde...

Mimicking cellular transport mechanisms to make solid-state smart nanochannels has long been of great interest for their diverse applications, but it poses a critical synthetic challenge. Covalent organic frameworks (COFs) are porous crystalline materials with tailor-made and hold potential ion molecule transport. We demonstrate here the first time that 2D COFs possess necessary merits be promising selective amino acids, which basis life. By imine condensations C3-symmetric trialdehyde...

Microporous covalent organic frameworks (COFs) hold great potential for small molecule separation but are yet challenging to design and synthesize. Here we report a framework interpenetration strategy make microporous COFs efficient separations of C8 alkyl-aromatic isomers. Two pairs three-dimensional (3D) salen- Zn(salen)-based prepared by Schiff-base condensation ethanediamine with tetrahedral tetra(salicylaldehyde)-silane or -methane derivatives in the presence absence metal ions. The...

While crystalline covalent organic frameworks (COFs) linked by C–C bonds are highly desired in synthetic chemistry, it remains a formidable challenge to synthesize. Efforts generate single COFs via de novo synthesis usually afford amorphous structures rather than phases. We demonstrate here that bond-based can be prepared direct reduction of C═C bond-linked crystal-to-crystal transformation. By Knoevenagel polycondensation chiral tetrabenzaldehyde dibinaphthyl-22-crown-6 with...

The metal–organic framework (MOF) HKUST-1 with a tbo topology serves as an archetypal tunable and isoreticular platform for targeting desired applications, but the design synthesis of tbo-covalent organic frameworks (COFs) remains formidable challenge. Here we demonstrate successful use reticular chemistry appropriate strategy deliberate construction COFs topology. judicious selection perquisite planar building blocks, 4-connected square tetramine porphyrin 3-connected trigonal trialdehydes...

Due to the inherent resistance of bacterial biofilms antibiotics and their serious threat global public health, novel therapeutic agents strategies tackle are urgently needed. To this end, we designed synthesized a guanidinium-functionalized pillar[5]arene (GP5) that exhibited high antibacterial potency against Gram-negative E. coli (BH101) Gram-positive S. aureus (ATCC25904) strains. More importantly, GP5 effectively disrupted preformed by efficient penetration through biofilm barriers...

High-performance liquid chromatography (HPLC) and gas (GC) over chiral stationary phases (CSPs) represent the most popular highly applicable technology in field of separation, but there are currently no CSPs that can be used for both simultaneously. We demonstrate here two olefin-linked covalent organic frameworks (COFs) featuring crown ether groups general extensive separation not only GC also normal-phase reversed-phase HPLC. Both COFs have same 2D layered porous structure channels...

The separation of enantiomers using high-performance chromatography technologies represents great importance and interest. In this aspect, β-cyclodextrin (β-CD) its derivatives have been extensively studied as chiral stationary phases (CSPs). Nevertheless, β-CD that was immobilized on a traditional matrix often exhibited low stabilities limited operating ranges. Recently, covalent organic frameworks (COFs) with highly ordered nanopores are emerging promising CSPs for enantioseparations, but...

Privileged diphosphine ligands that chelate many transition metals to form stable chelation complexes are essential in a variety of catalytic processes. However, the exact identity catalytically active moieties remains ambiguous because chelated metal catalysts may undergo rearrangement during catalysis produce monophosphine-metal complexes, which hard isolate and evaluate activities. By taking advantage isolation two phosphorus atoms, we demonstrate here successful construction chiral...

The preservation of chirality during a transformation process, known as the "chiral memory" effect, has garnered significant attention across multiple research disciplines. Here, we first report retention original chiral structure dynamic covalent chemistry (DCC)-induced structural from porous organic cages into frameworks (COFs). A total six two-dimensional COFs constructed by entirely achiral building blocks were obtained through DCC-induced substitution linkers in homochiral cage (CC3-R...

A variety of linear and cross-linked polysiloxanes are transformed into silicon oxide (SiOx) through the application a recently developed room-temperature UV/ozone conversion process. Ozone atomic oxygen, produced by exposure atmospheric oxygen to ultraviolet radiation, remove organic portions polymers as volatile products leave thin surface film. The rates differ for each polysiloxane studied related differences in their chemical structures. X-ray photoelectron spectroscopy (XPS)...

Abstract A novel enantioselective palladium‐catalyzed dearomative cyclization has been developed for the efficient construction of a series chiral phenanthrenone derivatives bearing an all‐carbon quaternary center. The effectiveness this method in synthesis terpenes and steroids was demonstrated by highly kaurene intermediate, facile skeleton anabolic steroid boldenone, total antimicrobial diterpene natural product (−)‐totaradiol.

Covalent organic frameworks (COFs) show great promise as heterogeneous photocatalysts, but they have not yet been explored for asymmetric photocatalysis, which is important the sustainable production of pharmaceuticals and fine chemicals.

Effective solid acid catalysts play a key role to produce high-quality biodiesel through triglyceride transesterification.

Covalent organic frameworks (COFs) hold great potentials for addressing the challenge of highly efficient oil-water separation, but they are restricted by poor wettability and processability as crystalline membranes. Here we report design synthesis two-dimensional (2D) robust COFs with controllable hydrophobicity processability, allowing COF layers to be directly grown on support surfaces. Three 2D AA or ABC stacking prepared condensation triamines fluorine and/or isopropyl groups...

Abstract Dimensionality is a fundamental parameter to modulate the properties of solid materials by tuning electronic structures. Covalent organic frameworks (COFs) are prominent class porous crystalline materials, but study dimensional dependence on their physicochemical still lacking. Herein we illustrate photocatalytic performances N , ‐diaryl dihydrophenazine ( PN )‐based COFs heavily dependent structural dimensionality. Six isostructural imine‐bonded 2D‐PN and one 3D‐PN COF were...

Covalent organic frameworks (COFs) have undergone extensive research as heterogeneous catalysts for a wide range of significant reactions, but they not yet been investigated in the realm electrochemical asymmetric catalysis, despite their recognition an economical and sustainable strategy producing enantiopure compounds. Here, we report mixed-linker to design multicomponent two-dimensional (2D) chiral COFs with tunable layer stacking highly enantioselective electrocatalysis. By crystallizing...

Capillary electrochromatography (CEC) is a rapidly emerging separation technique that merges the high efficiency of capillary electrophoresis with exceptional selectivity liquid chromatography. However, it remains synthetic challenge to design functional chiral stationary phases (CSPs) chemical stability against acid and base in CEC enantioseparation. Here we demonstrate incorporating crown ethers into stable covalent organic frameworks (COFs) enables efficient separations racemates by CEC....

Cassava and maize starches were mechanically treated with a stirring ball mill. The effects of ball-milling treatment on crystal structure thermal properties cassava examined by means X-ray diffraction differential scanning calorimetry. In addition, the physicochemical investigated analyzing influence apparent amylose content, cold-water solubility transparency. results showed that starch was destroyed ball-milling, crystallinity decreased from polycrystalline to amorphous. gelatinization...

Bimetal mixed MOFs of [CoZn][(BDC)(DABCO)0.5] (CZ-BDO), [CoNi][(BDC)(DABCO)0.5] (CN-BDO), and [NiZn][(BDC)(DABCO)0.5] (NZ-BDO) were prepared under solvothermal conditions further employed as highly active accelerants for converting carbon dioxide into cyclic carbonates. The characteristics the bimetal compounds revealed via various techniques, including ICP-OES, XRD, FT-IR, Raman, XPS, SEM, EDS maps, N2 adsorption, TG-DTG, CO2/NH3-TPD. catalytic results that CZ-BDO is superior to other...