A reversible photochromic covalent organic framework.

Covalent organic frameworks are a type of crystalline porous materials that linked through covalent bond, and they have numerous potential applications in adsorption, separation, catalysis, and more. However, there are rarely relevant reported on photochromism. Fortunately, a hydrazone-linked DBTB-DETH-COF is rapidly generated through ultrasound method.

Binaphthyl-based chiral covalent organic frameworks for chiral drug separation.

Separation of racemic drugs is of great importance and interest in chemistry and pharmacology. Here, we report the bottom-up synthesis of the binaphthyl-based chiral covalent organic frameworks (CCOFs), (R)-BHTP-COF. Then, high-performance liquid chromatography (HPLC) columns were prepared using (R)-BHTP-COF as a chiral stationary phase (CSP).

A BINOL-phosphoric acid and metalloporphyrin derived chiral covalent organic framework for enantioselective α-benzylation of aldehydes.

The catalytic asymmetric α-benzylation of aldehydes represents a highly valuable reaction for organic synthesis. For example, the generated α-heteroarylmethyl aldehydes, such as ()-2-methyl-3-(pyridin-4-yl)propanal (()-MPP), are an important class of synthons to access bioactive drugs and natural products. We report herein a new and facile synthetic approach for the asymmetric intermolecular α-benzylation of aldehydes with less sterically hindered alkyl halides using a multifunctional chiral covalent framework (CCOF) catalyst in a heterogeneous way.

Construction of acid-base bifunctional covalent organic frameworks Doebner reaction for catalysing cascade reaction.

We report herein a series of quinoline-4-carboxylic acid linked COFs the multicomponent one-pot Doebner reaction. The obtained acid-base bifunctional COFs are chemically stable and can highly promote one-pot cascade deacetalization-Knoevenagel condensation reaction in a heterogeneous way under solvent-free conditions.

Homochiral Covalent Organic Framework for Catalytic Asymmetric Synthesis of a Drug Intermediate.

()-2-(2-Chlorophenyl)-2-(6,7-dihydrothieno[3,2-]pyridin-5(4)-yl)acetonitrile (()-) is a key intermediate in the synthesis of ()-clopidogrel, which is one of the most saleable worldwide antiplatelet and antithrombotic drugs. We show herein a facile method for the direct synthesis of ()- via Strecker reaction using a homochiral covalent framework catalyst in a heterogeneous way. The asymmetric synthesis involves a photothermal-conversion-triggered, thermally driven reaction which affords ()- in 98% yield with 94% enantiomeric excess under visible-light irradiation.

Homochiral Covalent Organic Frameworks for Asymmetric Catalysis.

Owing to their permanent porosity, highly ordered and extended structure, good chemical stability, and tunability, covalent organic frameworks (COFs) have emerged as a new type of organic materials that can offer various applications in different fields. Benefiting from the huge database of organic reactions, the required functionality of COFs can be readily achieved by modification of the corresponding organic functional groups on either polymerizable monomers or established COF frameworks. This striking feature allows homochiral covalent organic frameworks (HCCOFs) to be reasonably designed and synthesized, as well as their use as a unique platform to fabricate asymmetric catalysts.

Construction of Covalent Organic Frameworks via Three-Component One-Pot Strecker and Povarov Reactions.

Postsynthetic modification (PSM) has been demonstrated to be a powerful method for achieving new covalent organic frameworks (COFs) via single-step or multistep organic functional group transformations on established COF frameworks. PSM, however, might sometimes lead to collapse of the COF framework, decreases in crystallinity, or low postsynthetic yield due to the inherent limit of solid-state synthesis. Herein we report, for the first time, a new synthetic strategy that can generate new COFs via multicomponent one-pot reactions.

Photothermal conversion triggered thermal asymmetric catalysis within metal nanoparticles loaded homochiral covalent organic framework.

For seeking high enantiopurity, the previously reported thermal asymmetric catalysis is usually carried out at low temperature sometimes with limited yield, that is, the high enantiomeric excess (ee) usually at the cost of high yield. Thus, the achieving both high stereoselectivity and yield is an enormous challenge. We report herein two metal nanoparticle (M NP)-loaded and porphyrin-containing homochiral covalent organic framework (CCOF)-based composite catalysts, and their application in the thermally-driven asymmetric one-pot Henry and A-coupling reactions.

Homochiral BINAPDA-Zr-MOF for Heterogeneous Asymmetric Cyanosilylation of Aldehydes.

A new homochiral was prepared by a new chiral organic linker of ()-4,4'-(6,6'-dichloro-2,2'-diethoxyl-[1,1'-binaphthalene]-4,4'-diyl)dibenzoic acid () and ZrCl under solvothermal conditions. Its structure was determined by Pawley refinement on the basis of the measured PXRD pattern determined for , and it showed that the obtained chiral MOF crystallized in the 2 space group with the same topological structure as that of UiO-66. The obtained can be a very active catalyst to catalyze aldehyde cyanosilylation.

Visible-light triggered selective reduction of nitroarenes to azo compounds catalysed by Ag@organic molecular cages.

Herein, a new Ag nanoparticle (Ag NP) loaded organic molecular cage is reported. The obtained Ag@1 can act as a highly efficient heterogeneous catalyst for the selective reduction of nitroarenes to azo compounds under visible-light irradiation.

CuL metal-organic cages for A-coupling reactions: reversible coordination interaction triggered homogeneous catalysis and heterogeneous recovery.

The reported Cu(ii) metal-organic cage (Cu3L2, 1) can be a highly active reusable catalyst to homogeneously catalyze the A3-coupling reaction in CHCl3 and can be heterogeneously recovered by simply adding 1,4-dioxane via formation of the insoluble metal-organic framework (Cu3L2(1,4-dioxane)1.5, 2).

Ru Nanoparticles-Loaded Covalent Organic Framework for Solvent-Free One-Pot Tandem Reactions in Air.

Condensation of benzene-1,3,5-tricarbohydrazide with benzene-1,4-dicarboxaldehyde generated a new covalent organic framework, COF-ASB (1), in which the organic units are held together via hydrazone linkage to form porous frameworks. COF-ASB (1) is highly crystalline and displays good chemical and thermal stability and is permanently porous. In addition, 1 can be an ideal support to load Ru nanoparticles (Ru NPs) to generate Ru@COF-ASB (2).

Dual Heterogeneous Catalyst Pd-Au@Mn(II)-MOF for One-Pot Tandem Synthesis of Imines from Alcohols and Amines.

A new Mn(II) metal-organic framework (MOF) 1 was synthesized by the combination of 4,4,4-trifluoro-1-(4-(pyridin-4-yl)phenyl)butane-1,3-dione (L) and Mn(OAc) in solution. 1 features a threefold-interpenetrating NbO net containing honeycomb-like channels, in which the opposite Mn(II)···Mn(II) distance is 23.5075(10) Å.

A drug-loaded nanoscale metal-organic framework with a tumor targeting agent for highly effective hepatoma therapy.

Drug delivery systems with targeting agents for precise drug release in cancer therapy are very significant and important. Herein, we report the rational design and synthesis of a DOX (doxorubicin) loaded UiO-68-type of nanoscale metal-organic framework (NMOF) with a tumor targeting agent (folic acid, FA), DOX@UiO-68-FA (3), as a multifunctional drug delivery system for hepatoma (Hep G2) therapy via tail-vein injection. Compared to free DOX, FA-unloaded DOX@Mi-UiO-68 (2), 3 exhibits a much higher antitumor efficacy, which was confirmed by cell imaging, standard 3-(4,5-dimethylthiahiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) proliferation and in vivo experiments.

Cu(ii)/Cu(0)@UiO-66-NH: base metal@MOFs as heterogeneous catalysts for olefin oxidation and reduction.

Two copper-loaded MOF materials, namely Cu(ii)@Ui-O-66-NH (1) and Cu(0)@UiO-66-NH (2), are reported. They can, respectively, serve as highly efficient heterogeneous catalysts for olefin oxidation and hydrogenation under mild conditions. Complete styrene hydrogenation occurs in 15 min at ambient temperature with quantitative yield.

Au@Cu(II)-MOF: Highly Efficient Bifunctional Heterogeneous Catalyst for Successive Oxidation-Condensation Reactions.

A new composite Au@Cu(II)-MOF catalyst has been synthesized via solution impregnation and full characterized by HRTEM, SEM-EDS, XRD, gas adsorption-desorption, XPS, and ICP analysis. It has been shown here that the Cu(II)-framework can be a useful platform to stabilize and support gold nanoparticles (Au NPs). The obtained Au@Cu(II)-MOF exhibits a bifunctional catalytic behavior and is able to promote selective aerobic benzyl alcohol oxidation-Knoevenagel condensation in a stepwise way.

Pd(0)@UiO-68-AP: chelation-directed bifunctional heterogeneous catalyst for stepwise organic transformations.

A bifunctional heterogeneous catalyst Pd(0)@UiO-68-AP based on a chelation-directed post-synthetic approach is reported. It exhibits typical heterogeneous catalytic behaviour and can promote benzyl alcohol oxidiation-Knoevenagel condensation in a stepwise way.

Pd@Cu(II)-MOF-Catalyzed Aerobic Oxidation of Benzylic Alcohols in Air with High Conversion and Selectivity.

A new 3D porous Cu(II)-MOF (1) was synthesized based on a ditopic pyridyl substituted diketonate ligand and Cu(OAc)2 in solution, and it features a 3D NbO motif which is determined by the X-ray crystallography. Furthermore, the Pd NPs-loaded hybrid material Pd@Cu(II)-MOF (2) was prepared based on 1 via solution impregnation, and its structure was confirmed by HRTEM, SEM, XRPD, gas adsorption-desorption, and ICP measurement. 2 exhibits excellent catalytic activity (conversion, 93% to >99%) and selectivity (>99% to benzaldehydes) for various benzyl alcohol substrates (benzyl alcohol and its derivatives with electron-withdrawing and electron-donating groups) oxidation reactions in air.

Nanoscale UiO-MOF-based luminescent sensors for highly selective detection of cysteine and glutathione and their application in bioimaging.

We report a practical approach, the first of its kind, to construct nanoscale UiO-type metal-organic framework (Mi-UiO-66 and Mi-UiO-67) fluorescent probes for the detection of Cys and GSH. They showed high sensitivity (10(-11) M) and selectivity for Cys and GSH, and their fluorescence imaging of Cys and GSH in living cells was well demonstrated.

Fabrication of Cd(II)-MOF-based ternary photocatalytic composite materials for H2 production via a gel-to-crystal approach.

Cd(II)-MOF-based ternary composite materials of CdS@Cd(II)-MOF@TiO2 were prepared by a unique TiO2 induced gel-to-crystal approach. CdS@Cd(II)-MOF@TiO2 was demonstrated to be a highly active photocatalyst for hydrogen production under visible light based on water photolysis.

[Dy(acac)₃(dppn)]·C₂H₅OH: construction of a single-ion magnet based on the square-antiprism dysprosium(III) ion.

The present work reports a new mononuclear Dy(III) complex [Dy(acac)3(dppn)]·C2H5OH (1) (acac = acetylacetone, dppn = benzo[i]dipyrido-[3, 2-a:2',3'-c]phenazine). X-ray crystallography analysis reveals that compound 1 is a discrete molecular complex and the Dy(III) center lies in a square-antiprism coordination environment. Furthermore, complex 1 shows single-ion magnet (SIM) behavior.

Synthesis, DNA binding, photo-induced DNA cleavage, cytotoxicity studies of a family of heavy rare earth complexes.

As a continuing investigation of our previous studies about the influence of the different rare earth metal ions on the bioactivity, a family of heavy rare earth metal complexes, [RE(acac)3(dpq)] (RE=Tb (1), Dy (2), Ho (3), Er (4), Tm (5), Yb (6), Lu (7)) and [RE(acac)3(dppz)]·CH3OH (RE=Tb (8), Dy (9), Ho (10), Er (11), Tm (12), Yb (13), Lu (14) viz. acetylacetonate (acac), dipyrido[3,2-d:20,30-f]quinoxaline (dpq), dipyrido[3,2-a:20,30-c] phenazine (dppz)), has been synthesized and their biological activities were also investigated. On the irradiation with UV-A light of 365nm or ambient light, all complexes exhibit efficient DNA cleavage activity via the mechanistic pathway involving the formation of singlet oxygen and hydroxyl radical as the reactive species.

Impact of metal on the DNA photo-induced cleavage activity of a family of Phterpy complexes.

A family of Phterpy complexes, [Mn(Phterpy)2][N(CN)2]2·0.5H2O (1), [Fe(Phterpy)2](NO3)2 (2), [Ni(Phterpy)2](NO3)2 (3), [Ni(Phterpy)2]Cl2·10H2O (4), [Cd(Phterpy)2](NO3)2·2H2O (5) and [Zn(Phterpy)Cl2] (6) (Phterpy=4'-phenyl-2,2':6',2″-terpyridine), have been synthesized and structurally characterized, and their DNA binding and photo-induced DNA cleavage activities have been investigated. These complexes display binding propensity to the CT-DNA giving a relative order: 1>4>3, 5, 2, 6.

Synthesis, DNA binding, photo-induced DNA cleavage and cell cytotoxicity studies of a family of light rare earth complexes.

A family of light rare earth complexes, [RE(acac)(3)(dpq)] (RE=La (1), Ce (2), Pr (3), Nd (4), Sm (5)) and [RE(acac)(3)(dppz)].CH(3)OH (RE=La (6), Ce (7), Pr (8), Nd (9), Sm (10) viz. acetylacetonate (acac), dipyrido[3,2-d:20,30-f]quinoxaline (dpq), dipyrido[3,2-a:20,30-c] phenazine (dppz)), have been synthesized and structurally characterized.