Economically Scalable Cu-based MOFs: Vital Role of Structural Integrity towards Selectivity on Azeotropic Ethanol Dehydration.

A facile, green, and economical method for the scalable synthesis of hydrophilic copper-triazole metal-organic frameworks (Cu-trz) is demonstrated. Numerous open metal sites within the highly crystalline porous structure of Cu-trz are generated through mild thermal activation, enabling its application in liquid-phase ethanol dehydration under ambient conditions. The frameworks with distinct crystallinity and particle sizes were achieved by modifying the synthesis process.

Abietane Diterpenoids from the Rhizomes of and Their Anti-Inflammatory Activities.

Six new abietane diterpenes, roscoeananes A-F (-), along with two known compounds (-) were isolated from the rhizomes of . The structures of all compounds were elucidated by analysis of spectroscopic data, and the absolute configurations were assigned by a comparison of the theoretical and experimental electronic circular dichroism (ECD) spectra and a comparison with literature values. The unreported compound is an ether-linked dimer of roscoeanane B ().

Tuning Electronic and Proton Transfer Properties on Amino-Functionalized Co-Based MOF for Efficient Photocatalytic Hydrogen Evolution.

Efficient hydrogen (H) production through photocatalytic water splitting was achieved by using an amino-functionalized azolate/cobalt-based metal-organic framework (MOF). While previous reports highlighted the amino group's role only as a substituent group for enabling light absorption of MOFs in the visible region, our present study revealed its dual role. The amino substituent not only acts as an electron donor to increase the electron availability at the active Co sites but also provides hydrogen-hopping sites within the pore channel, facilitating proton (H) diffusion along the framework.

Electrochemically Created Active Centers in a Bimetallic CoNi-Triazole Metal-Organic Framework for Enhanced Oxygen Evolution Reaction Activity.

Electrochemical water oxidation utilizing bimetallic CoNi-Tz (Tz=1,2,4-triazole) framework is explored. Initially, CoNi-Tz possesses active tetrahedral Co center and electron-mediated octahedral Ni chain. After performing an electrochemical activation, the partial structural transformation on the Ni center occurs.

Prussian Blue Analogue Glasses for Photoinduced CO Conversion.

Crystal-to-glass transformation is a powerful approach to modulating the chemical and physical properties of crystals. Here we demonstrate that the glass transformation of cobalt hexacyanoferrate crystals, one of the Prussian blue analogues, increased the concentration of open metal sites and altered the electronic state while maintaining coordination geometries and short-range ordering in the structure. The compositional and structural changes were characterized by X-ray absorption fine structure, energy dispersive X-ray spectroscopy, and X-ray total scattering.

Valorizing natural-abundant glucose to lactic acid using a MOF-808 catalyst under green hydrothermal conditions.

Highly robust Zr-based MOF-808, featuring Lewis acid Zr sites and coordinate hydroxide ions upon the removal of the monocarboxylate capping reagent, emerges as an efficient catalyst for the hydrothermal conversion of glucose into lactic acid. A remarkable 99% glucose conversion with an impressive 76.6% yield of lactic acid can be achieved.

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of .

Two new cassane diterpenoids, 14β-hydroxycassa-11(12),13(15)-dien-12,16-olide () and 6'-acetoxypterolobirin B (), together with a known analogue, identified as 12α,14β-dihydroxycassa-13(15)-en-12,16-olide (), were isolated from the fruits of . Compound is a cassane diterpenoid with a Δ double bond conjugated with an α,β-butenolide-type, whereas compound is a dimeric caged cassane diterpenoid with unique 6/6/6/6/6/5/6/6/6 nonacyclic ring system. The structures of and were characterized by extensive spectroscopic analysis combined with computational ECD analyses.

Photoexcited Anhydrous Proton Conductivity in Coordination Polymer Glass.

Optically switchable proton-conductive materials will enable the development of artificial ionic circuits. However, most switchable platforms rely on conformational changes in crystals to alter the connectivity of guest molecules. Guest dependency, low transmittance, and poor processability of polycrystalline materials hinder overall light responsiveness and contrast between on and off states.

Exploration of glassy state in Prussian blue analogues.

Prussian blue analogues (PBAs) are archetypes of microporous coordination polymers/metal-organic frameworks whose versatile composition allows for diverse functionalities. However, developments in PBAs have centred solely on their crystalline state, and the glassy state of PBAs has not been explored. Here we describe the preparation of the glassy state of PBAs via a mechanically induced crystal-to-glass transformation and explore their properties.

Co-based metal-organic framework for photocatalytic hydrogen generation.

Hydrogen production through an artificial photocatalytic process in the solar light region using a water-stable Co-Tz (Tz = 1,2,4-triazolate) framework was demonstrated. Possessing such a high photostability and highly reactive sites at the tetrahedral cobalt centers, Co-Tz exhibits a great photocatalytic performance converting water into hydrogen of 9.32 mmol g at 4 h in the presence of fluorescein (FI) and triethylamine (TEA) as a photosensitizer and sacrificial agent, respectively.

Separation of Etiracetam Enantiomers Using Enantiospecific Cocrystallization with 2-Chloromandelic Acid.

Chirality plays an important role in the pharmaceutical industry since the two enantiomers of a drug molecule usually display significantly different bioactivities, and hence, most products are produced as pure enantiomers. However, many drug precursors are synthesized as racemates, and hence, enantioseparation has become a significant process in the industry. Cocrystallization is one of the attractive crystallization approaches to obtain the desired enantiomer from racemic compounds.

Conductive Co-triazole metal-organic framework exploited as an oxygen evolution electrocatalyst.

A Co-triazole metal-organic framework (Co-trz) endowed with electrical conductivity was synthesized effortlessly a microwave-based method. Providing a high density of catalytic centers with electrically conductive features, as suggested by DFT calculations, the framework exhibited a low overpotential for the oxygen evolution reaction (OER) with good kinetics. A mechanistic reaction pathway was proposed based on monitoring alterations in the oxidation state and local coordination environment of Co centers upon the occurrence of the OER.

Bandgap Modulation in Zr-Based Metal-Organic Frameworks by Mixed-Linker Approach.

Metal-organic frameworks (MOFs) have been a promising material for many applications, e.g., photocatalysis, luminescence-based sensing, optoelectronics, and electrochemical devices, due to their tunable electronic properties through linker functionalization.

Selective cyclohexene oxidation to allylic compounds over a Cu-triazole framework homolytic activation of hydrogen peroxide.

Utilization of metal-organic frameworks as heterogeneous catalysts is crucial owing to their abundant catalytic sites and well-defined porous structures. Highly robust [Cu3(trz)3(μ3-OH)(OH)2(H2O)4]·2H2O (trz = 1,2,4-triazole) was employed as a catalyst for liquid-phase cyclohexene oxidation with hydrogen peroxide (H2O2). Possessing the porous structure together with Lewis acid attributes from the triangular [Cu3(trz)3(μ3-OH)] center, selective oxidation of cyclohexene to allylic products gives a molar yield of 31% with 87% selectivity.

Biotransformation of 1α,11α-dihydroxyisopimara-8(14),15-diene by Cunninghamella echinulata NRRL 1386 and their neuroprotective activity.

The isopimarane diterpene, 1α,11α-dihydroxyisopimara-8(14),15-diene (1), is the major constituents from the rhizomes of Kaempferia marginata (Zingiberaceae), a Thai medicinal plant. The microbial transformation of parent compound 1 by the fungus Cunninghamella echinulata NRRL 1386 gave five new metabolites, 7α,11α-dihydroxy-1-oxoisopimara-8(14),15-diene (2), 3β,7α,11α-trihydroxy-1-oxoisopimara-8(14),15-diene (3), 7β,11α-dihydroxy-1-oxoisopimara-8(14),15-diene (4), 7α-hydroxy-1,11-dioxoisopimara-8(14),15-diene (5) and 1α,7β,11α-trihydroxyisopimara-8(14),15-diene (6), together with three known metabolites, 7-9. The structures of the new metabolites were elucidated by spectroscopic techniques.

Fourfold alkyl wrapping of a copper(II) porphyrin thwarts macrocycle π-π stacking in a compact supramolecular package.

Porphyrins are valuable constituents in optoelectronic, catalytic, and other applications, yet control of intermolecular π-π stacking is invariably essential to attain the desired properties. Superstructures built onto the porphyrin, often via meso-aryl groups, can afford facial encumbrance that suppresses π-π stacking, although some molecular designs have provided insufficient facial coverage and many have entailed cumbersome syntheses. In this study, a copper(II) porphyrin bearing four meso substituents, namely, {10,20-bis[2,6-bis(octyloxy)phenyl]-5,15-dibromoporphinato}copper(II), [Cu(CHBrNO)], was prepared by metalation of the corresponding free-base porphyrin and was characterized by single-crystal X-ray diffraction.

Engineering zirconium-based UiO-66 for effective chemical conversion of d-xylose to lactic acid in aqueous condition.

Utilizing metal-organic frameworks (MOFs) as heterogeneous catalysts is an interesting and important application due to their well-controlled catalytic sites and well-defined porous structures. In this study we apply, for the first time, Zr-based UiO-66 for the catalytic hydrothermal conversion of d-xylose to lactic acid (LA). The reactions are catalyzed by the coordinatively unsaturated Zr, as Lewis acid sites, and the hydroxide ion (OH) located at the defect sites.

Methane Utilization to Methanol by a Hybrid Zeolite@Metal-Organic Framework.

The development of an effective approach for methane utilization, especially methane conversion to methanol, is a crucial challenge that has remained unsolved satisfactorily. Herein, we propose an alternative concept of methane utilization to methanol over Fe-ZSM-5@ZIF-8. The concept is to use the designed composite as a dual catalyst in which ZIF-8 and Fe-ZSM-5 act simultaneously as a gas adsorbent and catalyst, respectively.

Isopimarane Diterpenoids from the Rhizomes of and Their Potential Anti-inflammatory Activities.

Six new isopimarane diterpenes, marginaols A-F (-), along with eight known compounds (-), were isolated from the rhizomes of . The structures and absolute configurations of - were established on the basis of spectroscopic methods and the experimental and calculated ECD data as well as comparison with the literature values. Most of the isolated compounds were tested for their nitric oxide (NO) inhibitory effects in lipopolysaccharide-activated RAW264.

A proton transfer mechanism along the PO anion chain in the [Zn(HPO)(HPO)] coordination polymer.

In this study, we revisit the proton transfer mechanism in [Zn(HPO4)(H2PO4)]2-, a coordination polymer possessing high proton conductivity. In a previous report [N. Phattharasupakun, J.

Adsorption-Induced Dye Stability of Cationic Dyes on Clay Nanosheets.

Rhodamine 6G (R6G) was adsorbed on smectite clays, a natural montmorillonite, a synthetic saponite, and synthetic hectorites, and the decolorization of the dyes upon visible light irradiation was examined for aqueous suspensions and cast films. Excellent dye stability was achieved when a natural montmorillonite was used. Apart from R6G, better photostability was also achieved when the tris(2,2'-bipyridine)ruthenium(II) complex was adsorbed on a natural montmorillonite.

Unsaturated Mn(II)-Centered [Mn(BDC)] Metal-Organic Framework with Strong Water Binding Ability and Its Potential for Dehydration of an Ethanol/Water Mixture.

An unsaturated Mn(II)-centered metal-organic framework was synthesized. The presence of an unsaturated Mn(II) center, together with a guest-responsive structural changing feature, plays a crucial role for strong binding with water, leading to its potential application for water/ethanol separation. In addition, the present framework is thermally stable up to 400 °C, which is beneficial for the regeneration process after adsorption.

Polymerization of ε-Caprolactone Using Bis(phenoxy)-amine Aluminum Complex: Deactivation by Lactide.

Polymerizations of biodegradable lactide and lactones have been the subjects of intense research during the past decade. They can be polymerized/copolymerized effectively by several catalyst systems. With bis(phenolate)-amine aluminum complex, we have shown for the first time that lactide monomer can deactivate the aluminum complex during the ongoing polymerization of ε-caprolactone to a complete stop.

Hierarchical FAU/ZIF-8 Hybrid Materials as Highly Efficient Acid-Base Catalysts for Aldol Condensation.

The composite of hierarchical faujasite nanosheets and zeolitic imidazolate framework-8 (Hie-FAU-ZIF-8) has been successfully prepared via a stepwise deposition of ZIF-8 on modified zeolite surfaces. Compared to the direct deposition of metal organic frameworks (MOFs) on zeolite surfaces, ZIF-8 nanospheres were selectively attached to the external surfaces of the MOF ligand-grafted FAU crystals because of the enhancing interaction between the zeolite and MOF in the composite. In addition, the degree of surface functionalization can be greatly enhanced because of the presence of hierarchical structures.

Mechanochemical methods for the preparation of intercalation compounds, from intercalation to the formation of layered double hydroxides.

Due to increasing interest in the development of advanced nanomaterials from nanosheets as building blocks, methods for the preparation of nanosheet materials and their hybrids have been studied carefully and extensively. In this review, studies of mechanochemical methods (solid-solid reactions under ambient conditions or solvent-free synthesis) for the preparation of intercalation compounds are summarized. Mechanochemical reactions without using solvent have operational advantages, such as their environmentally benign nature and the fact that separating and drying the products is not necessary.