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Photoredox/metal dual catalysis is a versatile tandem methodology to construct carbon–carbon and carbon–heteroatom bonds. The focus of this short review is the application of this technology to C(sp3)–C(sp3), C(sp3)–C(sp2), C(sp2)–C(sp2), C(sp2)–O, and C(sp3)–O bond formation induced by readily available and inexpensive carbonyl complexes as single electron transfer agents, photosensitizers, or hydrogen atom transfer agents. 1 Introduction 2 Homocoupling of Aryl Halides 3 Functionalization of C(sp3)–H Bonds 3.1 Dehydrogenation of Alkanes 3.2 Arylation/Alkylation 3.3 Carboxylation 3.4 Acylation 3.5 Hydroalkylation of Olefins 3.6 Hydroalkylation of Imines 4 Benzoylation of Aryl Bromides 5 Aryl Esterification 6 Oxidation of β-Keto Esters 7 Conclusions and Future Outlook [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) are potential thermoelectric (TE) materials to replace the sometimes costly, brittle and toxic heavy metal inorganic TEs for near-ambient-temperature applications. Air-stable and highly conductive p-type thermoelectric CPs are relatively well known, but the their n-type counterparts are only now emerging and both are needed for most practical applications. This perspective reviews recent advances in the development of n-type thermoelectric CPs, particularly the 1D and 2D metal bisdithiolenes, and introduces a relatively new class of guest@metal–organic framework(MOF)-based composites. Low dimensional CPs with reasonable n-type thermoelectric performance are emerging with good charge mobility and air-stability but still relatively low electrical conductivity. [ABSTRACT FROM AUTHOR]

Earth-abundant copper(I) coordination complexes of an imine-phosphine and a diimine have been developed as visible-light photocatalysts. Reaction of [Cu(MeCN)4]BF4 with hetero-bidentate phosphinopyrazole (phpz) ligand R1R2C3HN2PPh3 (R1 = R2 = H (1a); R1 = H, R2 = Me (1b); R1 = H, R2 = Ph (1c); R1 = R2 = Me (1d)) and 2,9-dimethyl-1,10-phenanthroline (dmp) gave four heteroleptic bis-chelate Cu(I) complexes [Cu(dmp)(R1R2C3HN2PPh3)]BF4 (R1 = R2 = H (2a); R1 = H, R2 = Me (2b); R1 = H, R2 = Ph (2c); R1 = R2 = Me (2d)) with distorted tetrahedral geometries. Complexes 2a–2d exhibited broad absorption in the visible spectrum and could facilitate photochemical intermolecular atom-transfer radical addition reactions of CBr4, or CCl3Br, CHI3 to styrenes in yields up to 91% and with a broad substrate scope. The absorption, emission, redox potential and photocatalytic activity were dependent on the substituents on the phpz ligand. Mechanistic studies supported an atom-transfer radical addition (ATRA) mechanism. [ABSTRACT FROM AUTHOR]

Stem cell culturing and differentiation is a very important research direction for tissue engineering. Thermogels are well suited for encapsulating cells because of their non-biotoxic nature and mild sol-gel transition as temperature increases. In particular, thermogels provide a 3D growth environment for stem cell growth, which is more similar to the extracellular matrix than flat substrates, so thermogels as a medium can overcome many of the cell abnormalities caused by 2D cell growth. In this review, we summarize the applications of thermogels in cell and stem cell culture in recent years. We also elaborate on the methods to induce stem cell differentiation by using thermogel-based 3D scaffolds. In particular, thermogels, encapsulating specific differentiation-inducing factor and having specific structures and moduli, can induce the differentiation into the desired tissue cells. Three dimensional thermogel scaffolds that control the growth and differentiation of cells will undoubtedly have a bright future in regenerative medicine. [ABSTRACT FROM AUTHOR]

Quinoline-triazoles 2-((4-(diethoxymethyl)-1H-1,2,3-triazol-1-yl)methyl)quinoline (1), 2-((4-(m-tolyl)-1H-1,2,3-triazol-1-yl)methyl)quinoline (2) and 2-((4-(p-tolyl)-1H-1,2,3-triazol-1-yl)methyl)quinoline (3) have been prepared with CuAAC click reactions and used as a model series to probe the relationship between lattice H-bonding interaction and crystal direction of growth. Crystals of 1-3 are 1D tape and prism shapes that correlate with their intermolecular and solvent 1D lattice H-bonding interactions. All compounds were thermally stable up to about 200 °C and blue-green emissive in solution. [ABSTRACT FROM AUTHOR]

The latest breakthroughs in the synthetic preparation of nanomaterials have led to an expanding library of novel, complex and shape controlled structures with unique characteristics. Anisotropic Janus particles (JPs) are asymmetrical and are able to endow diverse chemical and physical characteristics with directionality within a single particle. They are typically distributed into three classes, viz polymeric, inorganic and polymeric-inorganic and is made in a variation of morphologies including spherical, mushroom, snowman shaped, rod or cylindrical. Herein, we focus on JPs with a magnetic component, with emphasis on their fabrication, unique characteristics and recent applications. [ABSTRACT FROM AUTHOR]

Five halogen substituted pyrazolates, 4-chloro-3,5-diisopropylpyrazole (4-Cl-3,5-iPr2pzH), 4-bromo-3,5-diisopropylpyrazole (4-Br-3,5-iPr2pzH), 4-iodo-3,5-diisopropylpyrazole (4-I-3,5-iPr2pzH), 4-chloro-3,5-diphenylpyrazole (4-Cl-3,5-Ph2pzH), and 4-bromo-3,5-diphenylpyrazole (4-Br-3,5-Ph2pzH), were conveniently prepared by halogenation of the appropriate pyrazoles with N-halosuccinimides (NXS) (X = Cl, Br, and I) followed by complexation of the pyrazolate anions with silver(I) nitrate. Single crystal X-ray analysis revealed either dimeric trinuclear {[Ag(μ-4-X-3,5-R2pz)]3}2 (R = iPr, X = Cl, Br, and I) or trinuclear [Ag(μ-4-X 3,5-R2pz)]3 (R = iPr, X = I; R = Ph, X = Cl, R = Ph, X = Br) structures, the latter held together with argentophilic interactions (Ag···Ag interactions) that could also be observed in the Raman spectra. The electronegativity of the halogen substituent could be correlated with the strength of the Ag···Ag interaction and the wavelength of solid-state photoluminescence. All complexes were emissive on UV irradiation at low temperatures, with the colour of emission from the diisopropyl substituted analogues red shifted by the halogens in the order Cl (red) > Br (orange) > I (yellow). Emission from the diphenyl substituted analogues was dominated by the extended aromatic system and was largely invariant to the halogens. [ABSTRACT FROM AUTHOR]

We have developed a catalyst-free visible-light-driven C(sp2)–H arylation of unprotected phenols with arylbromides to give 2-arylated phenols. This reaction proceeds through the excitation of an electron donor–acceptor complex between a phenolate and an arylbromide, electron transfer, and debrominative C(sp2)–C(sp2) coupling. [ABSTRACT FROM AUTHOR]

Abstract: This communication reports the preparation of two new cyclodextrin (CD) chiral stationary phases (CSPs): heptakis(6-deoxy-6-azido)-β-CD and heptakis(6-deoxy-6-azido-phenylcarbamoylated)-β-CD CSPs that perform quite differently to our previously reported “click” immobilized CD-CSPs. These CSPs are sterically congested at the narrow mouth of the CD and exhibit chiral discrimination between over 40 pairs of enantiomers in high performance liquid chromatography. The free hydroxyl CSP afforded better separation of indoprofen, ketoprofen, Tröger''s base, hydroxyl, carboxylic and dansyl amino acids than did the phenylcarbamoylated CSP, while the latter was better at resolving aryl alcohols, flavonoids, β-blockers and β-agonists. The current work shows that enantiodiscrimination achieved with different CSPs for different classes of analyte may be correlated with CD accessibility and peripheral functionality. [Copyright &y& Elsevier]

Pearl powder is a well-known traditional Chinese medicine for a variety of indications from beauty care to healthcare. While used for over a thousand years, there has yet to be an in-depth understanding and review in this area. The use of pearl powder is particularly growing in the biomedical area with various benefits reported due to the active ingredients within the pearl matrix itself. In this review, we focus on the emerging biomedical applications of pearl powder, touching on applications of pearl powder in wound healing, bone repairing, treatment of skin conditions, and other health indications. [ABSTRACT FROM AUTHOR]

It is well known that diazonium salts (ArN2+) react with phenols (Ar′OH) to give aryl diazoethers or diazo compounds, but their cross-coupling to exclusively access diaryl ethers is challenging. Herein we disclose the Cu-catalyzed etherification of phenols with aryl diazonium salts at room temperature, yielding diaryl ethers in moderate to excellent yields. The advantages of this protocol are mild reaction conditions, availability of reactants, operational simplicity, high tolerance of other functional groups and easy work-up. Its application to the synthesis of complex biological molecules is demonstrated. The reaction proceeds through single-electron transfer, extrusion of nitrogen, oxidative addition, and reductive elimination to give diaryl ether products. [ABSTRACT FROM AUTHOR]

A series of fluorescent coordination polymers (CPs) {[Cd 2 (CH 3 -bpeb) 2 (BDC) 2 CP1, (BDC) 0.5 /(NH 2 -BDC) 0.5 -CP1, (BDC) 0.34 /(NH 2 -BDC) 0.66 -CP1, (BDC) 0.25 /(NH 2 -BDC) 0.75 -CP1, (BDC) 0.2 /(NH 2 -BDC) 0.8 -CP1, (NH 2 -BDC)-CP1} were prepared from conjugated ligand 4,4′-((2-methyl-1,4-phenylene)bis(ethene-2,1-diyl))bipyridine (CH 3 -bpeb), terephthalic acid (BDC), aminoterephthalic acid (NH 2 -BDC) and CdSO 4 under solvothermal conditions. The fluorescence of aqueous suspensions of these CPs was quenched by folic acid (FA) in a concentration dependent manner. The efficiency of quenching increasing with an increased proportion of NH 2 -BDC ligand in the CP with (NH 2 -BDC)-CP1 exhibiting a low detection limit of 1.7 × 10−7 M. A series of coordination polymers {CP1, (BDC) 0.5 /(NH 2 -BDC) 0.5 -CP1, (BDC) 0.34 /(NH 2 -BDC) 0.66 -CP1, (BDC) 0.25 /(NH 2 -BDC) 0.75 -CP1, (BDC) 0.2 /(NH 2 -BDC) 0.8 -CP1, (NH 2 -BDC)-CP1} were obtained under solvothermal conditions. All materials have excellent fluorescence properties and can act as potential fluorescence sensing materials for the sensitive and selective detection of folic acid (FA). The presence of free amino groups in the structure significantly improves the detection of FA. Unlabelled Image • CPs contained different amount of amino group with excellent fluorescence properties were successfully synthesized. • The amino groups in the CPs structure can interact with FA and improve the sensitivity of FA detection. • Sensitive and selective detection of FA using coordination polymers as a kind of potential sensing materials. [ABSTRACT FROM AUTHOR]

Ru-Catalyzed acceptorless dehydrogenative coupling (ADC) and auto-transfer-hydrogenative (ATH) reactions are effective, versatile transformations for the constructions of N-heteroaromatic compounds from alcohols. Water and hydrogen are the by-products and the starting alcohols are less toxic, more readily available and more easily handled than their halogenated counterparts. A variety of homogeneous ruthenium catalysts, alcohols and partner-substrates such as amines, ammonia, amidines and nitriles, have been used to build N-heteroaromatic compounds in one-pot, multi-step syntheses. This review details recently reported Ru catalysts employed for these reactions, describing the scope of each methodology, proposed reaction mechanisms, regioselectivity of coupling and applications in synthesis. [ABSTRACT FROM AUTHOR]

The reaction of CF3COOAg, 3-bdppmapy (N,N-bis(diphenylphosphanylmethyl)-3-aminopyridine) and HTZ (1,2,4-triazole-3-thiol) in CH2Cl2/MeOH resulted in a dinuclear Ag/P/S complex [Ag2(TZ)2(3-bdppmapy)2]·xSol (1·xSol). Crystals of 1·xSol converted to 1·2MeOH in air at room temperature and further to 1 under vacuum upon heating. The solid-state, room-temperature photoluminescent emission of 1·xSol (510 nm) shifted to 494 nm (1·2MeOH) and 486 nm (1). Grinding solids of 1·2MeOH in air resulted in amorphous 1G characterized by solid-state emission at 468 nm, which converted to 1GR with 513 nm emission upon MeOH treatment. Grinding 1GR in air returned 1G, and this interconversion was reproducible over five cycles. The solid-state photoluminescence of 1G changed in response to vapors containing low–molecular weight alcohols but remained unchanged after exposure to other volatile organic compounds (VOCs) or to water vapor. Test papers impregnated with 1G could detect methanol in vapors from aqueous solutions at concentrations above 50%. Complex 1G is, therefore, an example of a stimuli-responsive molecular sensor for the detection of alcohols. [ABSTRACT FROM AUTHOR]

Herein are summarized recent trends in the use of hydrogels in robotics, electronics, actuators, and sensors. Two major gaps that limit the application of hydrogels in these fields are discussed, including hydrogels' inherent mechanical weaknesses and poor durability. Possible solutions to these problems include the introduction of self‐healing and the integration of biology inspired reinforcement mechanisms into synthetic systems. Enhancing hydrogels' water retention and interface bonding with other types of solid materials (such as glass, ceramics, metals, and elastomers) are also discussed. Addressing these latter issues is critical to the integration of hydrogels with other components in soft devices. It is argued that rapid, self‐healing, and mechanically strong biomimetic hydrogels will be an important material for the future. Realizing this goal will lead to new kinds of soft materials, new families of hydrogel‐based devices, and exciting new applications. [ABSTRACT FROM AUTHOR]

Coordination polymers of transition metal ions are fascinating and important to coordination chemistry. One of the ligands known to form particularly interesting coordination polymers is 3,3′,5,5′-tetramethyl-4,4′-bipyrazole (Me4bpzH2). Group 11 metal(I) ion coordination polymers, other than those of copper(I), are relatively easy to handle because of their low reactivity towards dioxygen and moisture. However, the known silver(I) coordination polymers often have poor solubility in common solvents and so cannot be easily analyzed in solution. By using a tetramethyl substituted bipyrazole ligand, we have synthesized more soluble silver(I) complexes that contain the trifluoromethyl group in the coordinated ions CF3CO2− and CF3SO3− in [Ag(CF3CO2)(Me4bpzH2)] and [Ag(CF3SO3)(Me4bpzH2)]. We determined both structures by single-crystal X-ray analysis at low temperatures and compared them in detail. Moreover, we investigated the solution behavior of these coordination polymers by 1H-NMR, IR, Raman, UV–Vis spectroscopies, and their low-temperature, solid-state photoluminescence. The high-energy band at ~330 nm corresponded to ligand-centered (bipyrazole) fluorescence, and the low-energy band at ~400 nm to ligand-centered phosphorescence resulting from the heavy atom effect. [ABSTRACT FROM AUTHOR]

The delivery of biocompatible reagents into cancer cells can elicit an anticancer effect by taking advantage of the unique characteristics of the tumor microenvironment (TME). In this work, we report that nanoscale two-dimensional FeII- and CoII-based metal–organic frameworks (NMOFs) of porphyrin ligand meso-tetrakis (6-(hydroxymethyl) pyridin-3-yl) porphyrin (THPP) can catalyze the generation of hydroxyl radicals (•OH) and O2 in the presence of H2O2 that is overexpressed in the TME. Photodynamic therapy consumes the generated O2 to produce a singlet oxygen (1O2). Both •OH and 1O2 are reactive oxygen species (ROS) that inhibit cancer cell proliferation. The FeII- and CoII-based NMOFs were non-toxic in the dark but cytotoxic when irradiated with 660 nm light. This preliminary work points to the potential of porphyrin-based ligands of transition metals as anticancer drugs by synergizing different therapeutic modalities. [ABSTRACT FROM AUTHOR]

A new Ag/Cu bimetallic cluster [Ag10Cu6(bdppthi)2(C≡CPh)12(EtOH)2](ClO4)4 (1, bdppthi = N,N′-bis(diphenylphosphanylmethyl)-tetrahydroimidazole) exhibited strong phosphorescent (PL) emission at 644 nm upon excitation at 400 nm. Removal of the coordinated EtOH molecules in 1 resulted in derivative 1a, which exhibited significant red-shifted emission at 678 nm. The structure and PL of 1 was restored on exposure to EtOH vapor. Cluster 1a also exhibited a vapor-chromic PL response towards other common organic solvent vapors including acetone, MeOH and MeCN. A PMMA film of 1a was developed as a reusable visible sensor for MeCN. [ABSTRACT FROM AUTHOR]

Highlights • High humidity causes water absorption in MgO boards with high chloride content. • Chloride concentration determination by EDS is a marker for staining. • Thermal analysis can be used to predict possible water absorption and staining. • There is need for quality control of chloride content and susceptibility to staining. Abstract Magnesium oxide (MgO) boards are relatively new cladding materials on the Australian construction market. They are chosen primarily for their fire resisting properties and are fast replacing traditional cladding materials in newer buildings. Recent reports of water staining on MgO boards is thought to be due to the effects of relative humidity promoting corrosion of metallic fasteners. Different commercially available MgO board samples were investigated by following their behaviour in a controlled relative humidity environment and when in contact with different metallic fasteners. It is observed that water absorption is different for different products and that staining varied with the composition of the metallic fasteners. Staining and water absorption was not a problem at a low relative humidity (RH) of 75% but was evident at a high humidity of 97% for all but one of the MgO board samples. The concentration of chloride is implicated and has its origin in the binder material. These results emphasise the need for standard characterisation of commercially available MgO boards for their use in high humidity environments. [ABSTRACT FROM AUTHOR]

Highlights • IC and free catechin was more stable in a solid matric. • IC in milk and yogurt showed the highest percentage recovery of catechin. • Semi-solid matrix (yogurt) was the most suitable matrix. • Inclusion complex of catechin with β-CD masked the bitterness of catechin. Abstract Catechin is astringent in taste, sparingly soluble in water and sensitive to oxygen, light and pH. These properties restrict its application in food products. The present study investigated the stability of inclusion complex (IC) and catechin in various food matrices and investigated in vitro recovery profile of catechin and IC in liquid, semi-solid and solid food matrices. Besides, the sensory profile of IC added yogurt was also determined. Results showed that IC and catechin was more stable in solid matrix compared to semi-solid and liquid matrices. IC added in milk and yogurt show the highest percentage recovery of catechin compared to IC added in cheese and catechin added in all the matrices in in vitro digestive system. Through IC, β-CD masked the bitterness of catechin. These results suggest that protection of antioxidant such as catechin by β-CD inclusion complex may have applications in functional foods and health supplements. [ABSTRACT FROM AUTHOR]

Abstract We have previously reported that the antioxidant activity of catechin degraded dramatically in a protein rich matrix compared to a sugar or oil-based matrix, and that this degradation was significantly retarded by β-cyclodextrin (β-CD) encapsulation. In the present study, we have probed the nature of this interaction of catechin and its β-CD inclusion complex with protein, sugar and oil models using fourier-transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. The former technique revealed a shift and increase in the intensity of the protein amide absorption bands upon mixing with catechin that was not observed with β-CD or with the corresponding encapsulated catechin, suggesting hydrogen bonding between this antioxidant and the protein amide groups. Catechin fluorescence was quenched by all three food models in a concentration dependent manner and this relationship was used to calculate binding constants in each matrix, which also revealed a strong interaction between catechin and protein that was reduced by encapsulation with β-CD. These new results help to explain our earlier observation of catechin degradation by protein and have implications for the use of this important antioxidant in food formulations. Highlights • Free catechin degraded dramatically in protein compared to a sugar and oil model. • Strong interaction was observed between catechin and protein. • Weak interaction was observed between β-CD encapsulated catechin and protein. • β-CD encapsulation helps to protect catechin from degradation. [ABSTRACT FROM AUTHOR]

The potential applications of catechin in food products are limited by its astringent taste, sparing solubility in water and sensitivity to oxygen, light and pH. A finishing formulation that is capable of protecting catechin is needed to deliver this antioxidant to its physiological targets with minimal loss of bioactivity. The aims of this study were to optimize the yield, microencapsulation efficiency and antioxidant properties of the inclusion complex (IC) and to determine the physicochemical properties and stability of β-CD-, HPβ-CD and Mβ-CD-complexed-catechin for potential functional food and health supplement applications. An inclusion complex prepared from 0.006 mol/L catechin and β-cyclodextrin (β-CD) with a 1:1 core to wall ratio showed the highest yield, encapsulation efficiency and antioxidant activity. Catechin complexed with β-CD more efficiently than with hydroxypropyl- β-cyclodextrin (HPβ-CD) or methyl- β-cyclodextrin (Mβ-CD). Encapsulation with β-CD was observed to double the water solubility of catechin. Particles of complexes ranging from 5 to 100 μm with spherical morphology were produced. 1 H NMR spectroscopy and DSC confirmed the host – guest complexation of catechin in the β-CD cavity. The current study shows that encapsulation of catechin with β-CD provides protection against temperature, light and oxygen. These inclusion complexes have potential applications as functional foods and health supplements. [ABSTRACT FROM AUTHOR]

The antioxidant catechin is astringent in taste, sparingly soluble in water and sensitive to oxygen, light and pH. These properties can restrict its application in food products. The present study investigated the effect of pH, relative humidity (RH) and various food components on this polyphenol's antioxidant stability, before and after encapsulation by β− cyclodextrin (β−CD) and by some alkylated β−CD derivatives. Catechin was observed to be very sensitive to pH (alkaline) and high relative humidity (>65%) but there was relatively little loss of antioxidant activity (61% antioxidant retention) for cyclodextrin inclusion complexes (ICs) under these conditions. Interestingly, free catechin degraded dramatically in a 40% protein model compared to a sugar or oil model, but this degradation was significantly retarded by β-CD complexation. These results suggest that protection of antioxidants and other sensitive components by β-CD encapsulation may have applications in functional foods and health supplements. [ABSTRACT FROM AUTHOR]

[L 2 Cu 4 I 4 ] n ( 1 ) based on a cubic [Cu 4 I 4 ] node and ditopic, bridging bis(triazole) (L = 2,6-bis((1 H -1,2,3-triazol-1-yl)methyl)pyridine) is a unique and highly symmetric cubane cluster based coordination polymer with strong yellow emission. Comparison with similar coordination polymers permits a structure activity relationship and reveals that the emission energy for these [Cu 4 I 4 ] cluster-based materials occurs in the mid-range of Cu⋅⋅⋅Cu distances and tetrahedral geometry index values. [ABSTRACT FROM AUTHOR]

RuCl3 efficiently catalyzes the alkylation of methylquinolines, methylpyridines, 2-methyl-benzooxazoles, and 2-methyl-quinoxalines with alkyl- or aryl-alcohols as alkylating agents. This synthetically useful and atom economical transformation does not require additional ligands. The mechanistic study indicated the alkylation reaction underwent a stepwise transfer hydrogenation, aldol condensation, and hydrogenation reaction pathway. [ABSTRACT FROM AUTHOR]

Pectins are a diverse family of biopolymers with an anionic polysaccharide backbone of α-1,4-linked d -galacturonic acids in common. They have been widely used as emulsifiers, gelling agents, glazing agents, stabilizers, and/or thickeners in food, pharmaceutical, personal care and polymer products. Commercial pectin is classified as high methoxy pectin (HMP) with a degree of methylation (DM) >50% and low methoxy pectin (LMP) with a DM <50%. Amidated low methoxy pectins (ALMP) can be obtained through aminolysis of HMP. Gelation of HMP occurs by cross-linking through hydrogen bonds and hydrophobic forces between the methyl groups, assisted by a high co-solute concentration and low pH. In contrast, gelation of LMP occurs by the formation of ionic linkages via calcium bridges between two carboxyl groups from two different chains in close proximity, known as the ‘egg-box’ model. Pectin gels exhibit Newtonian behaviour at low shear rates and shear-thinning behaviour when the shear rate is increased. An overview of pectin from its origin to its physicochemical properties is presented in this review. [ABSTRACT FROM AUTHOR]

Pectin is an anionic, water-soluble polymer predominantly consisting of covalently 1,4-linked α-D-galacturonic acid units. This naturally occurring, renewable and biodegradable polymer is underutilized in polymer science due to its insolubility in organic solvents, which renders conventional polymerization methods impractical. To circumvent this problem, cerium-initiated radical polymerization was utilized to graft methoxy-poly(ethylene glycol) methacrylate (mPEGMA) onto pectin in water. The copolymers were characterized by 1H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA), and used in the formation of supramolecular hydrogels through the addition of -cyclodextrin ( -CD) to induce crosslinking. These hydrogels possessed thixotropic properties; shear-thinning to liquid upon agitation but settling into gels at rest. In contrast to most of the other hydrogels produced through the use of poly(ethylene glycol) (PEG)-grafted polymers, the pectin-PEGMA/α -CD hydrogels were unaffected by temperature changes. [ABSTRACT FROM AUTHOR]

Four Cd(II)/diene coordination polymers (CPs) with similar 1D chain motifs exhibit different photosalient (PS) behaviours in response to UV light. The [2+2] photoreaction between the C＝C groups within these CPs results in diverse PS behaviours of their crystals with different C＝C pair arrangements. The interesting PS behaviours of these CPs can be applied in design and fabrication of advanced photoactuating materials. [ABSTRACT FROM AUTHOR]

Without using any additional ligands, RuCl3 efficiently catalyses the reductive N-alkylation of aryl nitro compounds with alcohols using bio-based glycerol as the hydrogen source and without the need for any added solvents. The reaction can be easily manipulated to produce either imines or secondary amines in high yields. RuCl3-catalyzed reductive N-alkylation of nitroarenes with alcohols affords the corresponding imine products in good to excellent yields. Under the same reaction conditions, the one-pot sequential reaction of nitroarenes with alcohols and glycerol also gives amines in higher yields. [ABSTRACT FROM AUTHOR]

Two new dinuclear CuII complexes [Cu2Cl4(L1)2] (1) and [Cu2Cl4(L2)2] (2) (L1 = 2-((4-(2-(cyclopentylthio)ethyl)-1H-1,2,3-triazol-1-yl)methyl)pyridine; L2 = 2-((4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)benzonitrile) were synthesised and characterised by single-crystal X-ray diffraction (XRD), powder XRD, thermogravimetric analysis, elemental analysis and IR measurements. The picolyl-triazole ligand L1 coordinates in a chelate-bridging mode forming a dinuclear structure 1. The more rigid pyridyl-triazole ligand L2 chelates only, generating a chloride-bridged dinuclear complex 2. Both crystals of complexes 1 and 2 show dominant plate shapes that correlate with weak 2D H-bonding interactions in the lattice. A mononuclear structure (3, [CuCl2(L3)2]·6H2O, L3 = 3-((4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)benzonitrile) yields block shape crystals that correlate with 3D H-bonding interactions. This study demonstrates tunable assembly at the molecular level and the relationship of crystal shape with weak lattice interactions. [ABSTRACT FROM AUTHOR]

Electron transfer dynamics in the oxide layers of the working electrodes in both dye-sensitized solar cells and photocatalysts greatly influences their performance. A proper understanding of the distribution of surface and bulk energy states on/in these oxide layers can provide insights into the associated electron transfer processes. Metal ions like Iron (Fe), Copper (Cu) and Tin (Sn) doped onto TiO 2 have shown enhanced photoactivity in these processes. In this work, the structural, optical and transient properties of Fe, Cu and Sn doped TiO 2 nanocrystalline powders have been investigated and compared using EDX, Raman spectroscopy, X-ray Photoelectron spectroscopy (XPS), and Transient Absorption spectroscopy (TAS). Surface free energy states distributions were probed using Electrochemical Impedance spectroscopy (EIS) on Dye Sensitized Solar Cells (DSSC) based on the doped TiO 2 photoanodes. Raman and XPS Ti2p 3/2 peak shifts and broadening showed that the concentration of defects were in the order: Cu doped TiO 2 > Fe doped TiO 2 > Sn doped TiO 2 > pure TiO 2 . Nanosecond laser flash photolysis of Fe and Cu doped TiO 2 indicated slower transient decay kinetics than that of Sn doped TiO 2 or pure TiO 2 . A broad absorption peak and fast transient decay at 430 nm for Fe doped TiO 2 was ascribed to an increase in surface hole concentration resulting in poor current density in the Fe doped TiO 2 photoanodes relative to pure TiO 2 , Sn or Cu doped anodes. The charge transfer capacitance and the calculated electron lifetimes correlated well with the trend in current density of the photoanodes (Sn > Cu > pure TiO 2 ). The poor performance of Fe doped cells is due to faster recombination of injected electrons with surface holes while those of Sn and Cu were more influenced by the concentration of their bulk defects. These results demonstrate that the choice of selected metal ions doping onto TiO 2 for a desired application should take into consideration the influence of bulk defect concentrations, the energy state distribution and the electron transfer properties in/on the oxide photoanodes. [ABSTRACT FROM AUTHOR]

Four structurally diverse coordination polymers 1–4 (CP1–CP4) were designed and constructed from Cd(II) ions and various carboxyl ligands (H2oba, 4,4′-oxydibenzoic acid; H2bpa, (E)-4,4′-(ethene-1,2-diyl)dibenzoic acid; H2pbda, 4,4′-((1,3-phenylenebis(methylene))bis(oxy))dibenzoic acid) and the alkene containing ligand (CH3-bpeb, 4,4′-((1E,1′E)-(2,5-dimethyl-1,4-phenylene)bis(ethene-2,1-diyl))dipyridine). CP1–CP4 possess Cd2 binuclear secondary building units (SBUs). The geometry of the dicarboxylate ligands and the reaction conditions determined the final structure with a variety of motifs. CP1 possesses an interdigitated 2D structure, while CP2 consists of a 1D channel-like motif with isolated CH3-bpeb molecules embedded in the channels. The solid-state structure of CP3 consists of two unique layers interpenetrated to form a 2D + 2D → 2D polycatenated backbone, while a 1D channel-like motif filled by isolated CH3-bpeb molecules was observed for CP4. In all four coordination polymers pairs of CH3-bpeb molecules were bound or encapsulated by the Cd2 secondary building units at an appropriate distance and orientation for solid-state [2 + 2] photodimerization of one pair of C＝C bonds. Desolvation of CP3 with heat resulted in a decrease in solid-state fluorescence and a slowing of the rate of solid-state photodimerization. [ABSTRACT FROM AUTHOR]

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) is a promising thermoelectric material with (bi)polaron-type transport properties. Dedoping PEDOT:PSS by simply controlling film thickness and the annealing temperature under high relative humidity led to partial reduction and a conformational change in the polymer that improved both the electrical conductivity and the Seebeck coefficient. When the film was hydrothermally annealed at 170 °C, its Seebeck coefficient was enhanced from 13.8 to 42.3 μV K−1. Water was the reducing agent and at an optimum annealing temperature of 130 °C facilitated separation of reduced PEDOT and protonated PSS chain, resulting in an improved power factor (PF) of 16.9 μW m−1 K−2 and a color change in the annealed PEDOT:PSS films from light to dark blue. The acid-treated PEDOT:PSS film followed by hydrothermal annealing exhibited a conductivity of 1241 ± 272 S cm−1 and 28.7 ± 2.1 μV K−1, and the corresponding PF was 103.9 μW m−1 K−2. These results show the possibility of tuning the thermoelectric properties of PEDOT:PSS films for biomedical applications without the need of toxic or expensive additives. [ABSTRACT FROM AUTHOR]

Reaction of [(3-bdppmapy)(AuCl)2] with NaHmba (3-bdppmapy = N,N′-bis-(diphenylphosphanylmethyl-3-aminopytidine, H2mba = 2-mercaptobenzoic acid) resulted in a new tetranuclear Au/P/S complex [(3-bdppmapy)2(AuHmba)3(AuCl)] (1). Upon excitation at 370 nm, 1 exhibited solid state, room temperature, green fluorescent emission (QY = 4.7%, τ = 2.58 ns) which was significantly enanced at lower temperatures due to strengthening of the Au–Au interaction. Different ratios of 1 with phosphor N630 in PMMA were used to make thermochromic photoluminescent films and fibres that could be fabricated into an optical thermometer sensitive over temperature ranges 80–300 K and 300–370 K. [ABSTRACT FROM AUTHOR]

Organic additives can enhance the amplified spontaneous emission (ASE) performance of inorganic cesium lead halide perovskites (CsPbBr3) but volatility, potential hygroscopicity and oxidative degradation of these additives jeopardizes the thermal stability and shelf‐life of blended CsPbBr3 films. To address this problem, we have fabricated perovskite films in a two‐step solution protocol involving as little added polyethylene oxide (PEO) as possible. These films exhibited enhanced crystallization, improved photoluminescence (PL) intensity and prolonged lifetimes. Their hierarchical morphology and surface passivation lowered the ASE threshold from 278 to 176 μЈ/cm2 under one‐photon nanosecond laser excitation. The proportion of added PEO was 0.3 wt% and was subsequently almost fully removed, thereby reducing its adverse influence on the stability of resulting films under continuous pulsed laser excitation. Stable ASE spectra could be stimulated after storage in air for 10 months. [ABSTRACT FROM AUTHOR]

Poly(3,4ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) has been intensively studied for its thermoelectric applications. Structural modulation to improve crystalline ordering, chain conformation and film morphology is a promising way to decouple the trade‐off between conductivity and Seebeck coefficient and thus improve the thermoelectric power factor. Post treatment with ionic liquid ([CoCl2 ⋅ 6H2O]:[ChCl]) bearing cobalt‐containing anions resulted in a remarkable enhancement of the power factor to 76.8 μW m−1 K−2. This IL combines the influence of a high‐boiling polar organic solvent and diffusing ions. A high σ mainly resulted from the efficient removal of PSS chains, ordering of the structure and delocalization of bipoloran‐dominant transport after conformational change. The increase in S was not due to dedoping of PEDOT chains, but rather the sharp feature of the density of states at the Fermi level induced by ion‐exchange with unconventional anions. [ABSTRACT FROM AUTHOR]

Quinolyl-1,2,3-triazole ligand supported [Cu4I4] stair-step aggregates [Cu4I4(L1)2] (1), [Cu4I4(L2)2] (2), [Cu4I4(L3)2] (3), [Cu4I4(L4)2] (4), [Cu4I4(L5)2] (5), and six-membered [Cu3I3] metallacycle based coordination polymers [Cu2I2(L6)]n (6) and [Cu2I2(L7)]n (7) (ligands are 2-((1H-1,2,3-triazol-1-yl)methyl)quinoline (L1), 2-((4-alkyl-1H-1,2,3-triazol-1-yl)methyl)quinoline (propyl, butyl and isobutyl for L2, L3 and L4, respectively) and 2-(1-((quinolin-2-yl)methyl)-1H-1,2,3-triazol-4-yl)alcohol (methanol, ethanol and propanol for L5, L6 and L7, respectively)) have been prepared and characterized by single-crystal X-ray diffraction (XRD), powder XRD, photoluminescence spectroscopy and thermogravimetric analysis. Complexes 1–5 are stair-step [Cu4I4] aggregate structures supported by two quinolyl-triazole hybrid ligands. Complexes 6 and 7 are rare cyclic [Cu3I3] aggregate-based 1-D coordination polymers. All ligands adopt a common tridentate-bridging coordination mode. These complexes are strongly luminescent with a yellow emission (500–700 nm) in the solid state. [ABSTRACT FROM AUTHOR]

Reaction of tetraphosphine (P4) ligand dppbpda with Ag(I) oxylates yielded new coordination polymers (CPs) of formula [(dppbpda)Ag4(Ox)4]n (Ox=Bz (1), Sal (2), LA (3), Bz=benzoate, Sal=salicylate, LA=lactate). The solid‐state structures of 1–3 consist of one dimensional (1D) chains constructed from tetranuclear μ‐η2,η2‐ connected Ag4(Ox)4 cluster cores and dppbpda bridging ligands. Compounds 1–3 absorbed Congo Red in two distinct steps, with maximum uptake quantities of 1438 (1), 1417 (2) and 1656 (3) mg/g, inversely correlating with the size of the anions in the CPs. These CPs had band gaps in the semiconducting region (Eg) 3.05–3.15 eV and all three showed enhanced two‐peak photocurrent responses during the stepwise adsorption of CR, with maximum photocurrent densities of 227 (1), 163 (2) and 386 (3) μA cm−2 for composites with optimized dye coverage. [ABSTRACT FROM AUTHOR]

Trinuclear complex [Au2Ag(dppmaphen)2(CN)2]PF6 photoluminesces on exposure to low molecular weight alcohols. This emission is likely due to C–H⋯π interactions between the analyte and –PPh2 group, that inhibits non-radiative relaxation of the photoexcited state. Photoluminescene was quenched by removing the analyte under a stream of N2 or replacing it with H2O. This on/off switching was clearly visible, relatively rapid and recyclable. [ABSTRACT FROM AUTHOR]

Coordination polymers [Cd(1,4-bpeb)(L1)] (1), [Zn2(1,4-bpeb)2(L2)2(SO42−)2] (2) and [Cd(1,4-bpeb)(L3)] (H2O) (3) (H2L1, 3-[2-(3-hydroxy-phenoxymethyl)-benzyloxy]-benzoic acid; HL2, 1H-Indazole-3-carboxylic acid; H3L3, benzene-1,2,3-tricarboxylic acid; 1,4-bpeb, 1,4-bis[2-(4-pyridyl)vinyl]benzene have been synthesized under solvothermal conditions. Complexes 1–3 underwent photodimerization in the solid-state to give quantitative yields of single isomeric products. The choice of carboxyl ligands L and metal center determined the arrangement of 1,4-bpeb ligands, which in turn directed the regiochemistry of the final photoproducts. The solid-state network structures of cadmium based 1 and 3 had 1,4-bpeb pairs aligned face-to-face with both C＝C centres in each ligand at an appropriate distance and alignment for photodimerization to give the corresponding para-[2.2]cyclophane (pCP) exclusively. By contrast, compound 2 possessed dinuclear (ZnSO4)2 metallocycles that positioned the 1,4-bpeb "arms" face-to-face, but with C＝C centres offset at an appropriate distance for only one pair to undergo [2 + 2] cycloaddition to yield a single stereoisomer of the monocyclobutane photo-product bpbpvpcb. This work highlights crystal engineering design principles that can be used to facilitate regio- and stereospecificity in solid-state transformations. [ABSTRACT FROM AUTHOR]

The diphosphine ligand N , N -bis(diphenylphosphanylmethyl)-aniline (bdppma) and PdCl2 afforded a Suzuki–Miyaura catalyst [(bdppma-)PdCl2 ] that was highly efficient at an ultralow catalyst loading (0.001 mol%) in 20:1 H2 O–EtOH. This low catalyst loading in an aqueous solvent system permitted simple product separation by direct filtration without the need for chromatography. The ligand bdppma imparted surprisingly better reactivity than that achieved with other bidentate diphosphine ligands, but the catalytic system had a slightly narrower substrate scope than some similar Pd catalysts reported previously. [ABSTRACT FROM AUTHOR]

A two‐step process of enzymatic hydrolyzation followed by Maillard reaction was used to produce oyster meat hydrolysate Maillard reaction products (MRPs). The flavor of oyster meat hydrolysate MRPs was significantly improved through an optimized orthogonal experimental design. Comparisons between the antioxidative activities of oyster meat hydrolysates and their MRPs were made using lipid peroxidation inhabitation, hydroxyl radical scavenging radical activity, and radical scavenging activity of 2,2 diphenyl‐1‐picrylhydrazyl (DPPH). These methods indicated that an improvement of Maillard reaction on the oyster meat hydrolysates antioxidative activity. Gas chromatography‐mass spectrometry illustrated that the increase was due to the newly formed antioxidative compounds after Maillard reaction, mainly of acids from 22.45% to 37.77% and phenols from 0% to 9.88%. [ABSTRACT FROM AUTHOR]

A conjugated nanoporous polycarbazole (CNP) cross-linked by pyridine and coordinated to Co(III) displays high catalytic performance for visible light-driven H2 generation. The hydrogen evolution rate was up to 410 μmol g−1 h−1. Spectroscopic and electrochemistry studies indicate that the redox active cobalt reduces recombination of photoexcited-charge-carriers and enhances the transmission of photoexcited-charge, thereby enriching the catalytic activity of hybrid materials x-Co/CNP-N (x = 5, 10, 15 and 20 wt%). [ABSTRACT FROM AUTHOR]

Six coordination polymers 1–6 were constructed using a rod and loop strategy, in which the H2L ligand served as the loop and the N-donor ligands (bpp, 1,4-bimb, 1,3-bimb, bpb, bpdp and bpeb; bpp = 1,3-di(pyridin-4-yl)propane; 1,4-bimb = 1,4-bis((1H-imidazol-1-yl)methyl)benzene; 1,3-bimb = 1,3-bis((1H-imidazol-1-yl)methyl)benzene; bpb = 1,4-di(pyridin-4-yl)benzene; bpdp = 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene; bpeb = 1,4-bis[2-(4-pyridyl)ethenyl]benzene) acted as the rods. All the complexes except 6 possessed binuclear secondary building units (SBUs) and displayed the same topologies. In compounds 1–4, two paddle-wheel Zn2 units were linked by two L ligands to form rhombic [Zn4L2] units and these units propagated into a chain-like motif. The N-donor ligands supported the chain-like structure and expanded into 2D layers. Three layers were interpenetrated forming a 2D + 2D → 2D polycatenation backbone. The 2D polycatenation layers were further packed into a 3D structure by hydrogen bonds and unconventional interactions. Compound 6 showed a 3D pillar-layer structure consisting of a four-fold interpenetrated network. This coordination polymer had an accessible volume of 38% for the fully desolvated structure and exhibited strong fluorescence that was selectively quenched by CrVI ions in aqueous solution at low concentrations. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tridentate planar N3 type ligands based by pyridine and pyrazoles were synthesized. • The structures of copper(II) chlorido complexes were distorted square-pyramidal. • The structure of copper(II) triflato complex was highly distorted octahedral. • Two different d-d bands were observed, depending on the different geometries. Tridentate, planar nitrogen containing ligands based on pyridine and pyrazoles were synthesized by the reaction of 2,6-dibromopyridine with the sodium salts of 3,5-dimethylpyrazole and 3,5-diisopropylpyrazole to yield 2,6-bis(3,5-dimethyl- N -pyrazolyl)pyridine (L0py) and 2,6-bis(3,5-diisopropyl- N -pyrazolyl)pyridine (L1py), respectively. The conformation of the pyrazole rings in the solid-state structures of both L0py and L1py were anti due to relatively low repulsion between the alkyl substituents. Both copper(II) chlorido complexes [CuCl 2 (L0py)] and [CuCl 2 (L1py)] were five-coordinate with solid-state structures best described as distorted square-pyramidal geometry involving N 3 Cl 2 donor sets. The ν(Cu–Cl) energies and Cu–Cl bond lengths were clearly different due to the different donating properties of the two ligands. By comparison, the structure of copper(II) trifluoromethanesulfonato complex [Cu(OTf) 2 (H 2 O)(L1py)] was six-coordinate with highly distorted octahedral geometry involving an N 3 O 3 donor set. The solution UV–Vis spectra of [CuCl 2 (L0py)] , [CuCl 2 (L1py)] , and [Cu(OTf) 2 (H 2 O)(L1py)] revealed π-π* transition bands red-shifted by ∼30 nm on complexation. The d-d transition bands of all three copper(II) complexes were observed at almost the same energy of ∼750 nm, while the corresponding solid-state UV–Vis spectra exhibited absorptions at ∼1010 nm and 674 nm due to differences in coordination geometry. These structural changes in the solution-state were supported by results from EPR spectroscopy. [ABSTRACT FROM AUTHOR]

Tetraphosphine ligand dpppda reacts with AgNO3 to generate two 1D coordination polymers containing cubic and chair-like [Ag4(NO3)4] clusters. ESR spectroscopy supported by DFT calculations indicated the presence of dpppdaṖ+, a Wurster's blue – like radical cation formed by intramolecular ligand-to-metal charge transfer (LMCT). This LMCT results in higher AgI→ Ag0 potentials and good photocurrent responses. [ABSTRACT FROM AUTHOR]

Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm−2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec−1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. [ABSTRACT FROM AUTHOR]

Ultrathin metal–organic framework (MOF) nanosheets (NSs) offer potential for many applications, but the synthetic strategies are largely limited to top‐down, low‐yield exfoliation methods. Herein, Ni–M–MOF (M=Fe, Al, Co, Mn, Zn, and Cd) NSs are reported with a thickness of only several atomic layers, prepared by a large‐scale, bottom‐up solvothermal method. The solvent mixture of N,N‐dimethylacetamide and water plays key role in controlling the formation of these two‐dimensional MOF NSs. The MOF NSs can be directly used as efficient electrocatalysts for the oxygen evolution reaction, in which the Ni–Fe–MOF NSs deliver a current density of 10 mA cm−2 at a low overpotential of 221 mV with a small Tafel slope of 56.0 mV dec−1, and exhibit excellent stability for at least 20 h without obvious activity decay. Density functional theory calculations on the energy barriers for OER occurring at different metal sites confirm that Fe is the active site for OER at Ni–Fe–MOF NSs. [ABSTRACT FROM AUTHOR]

Abstract Chirality transfer has been investigated with an m-phthalic diamide-linked zinc bisporphyrinate as host and chiral monoalcohols with different alkyl substituents as guests. The substituent of the guest alcohol had a significant effect on chirality transfer. An increase in the number of carbon atoms from one to three resulted in circular dichroism (CD) sign inversion for the corresponding host-guest complexes. The crystal structures of these zinc bisporphyrinate-monoalcohol complexes revealed two types of orientation for the phenyl ring of the guests: one with the phenyl ring facing the porphyrin plane, and the other with the phenyl ring towards the linker. The chirality transfer mechanism was further studied by DFT and revealed that adjusting the chain length of the alkyl substituent could control the steric interaction between the alkyl group and the porphyrin plane, resulting in different chirality transfer outcomes. Graphical abstract Image 1 Highlights • The host-guest complexes showed different CD signs when guests have different substituents. • Adjusting the alkyl substituents leads in different chirality transfer. • Two types of phenyl orientation of the guests were firstly evidenced by X-ray diffraction. • Different π–π interactions and steric interactions lead to different chirality transfer outcomes. [ABSTRACT FROM AUTHOR]

Ruthenium nanoparticles (NPs) supported on N‐doped carbon (Ru/N−C) were prepared by the pyrolysis of cis‐Ru(phen)2Cl2 loaded onto carbon powder (VULCAN XC72R) at 800 °C. Ru/N−C NPs (0.2 mol% Ru) selectively catalyzed either acceptorless dehydrogenation coupling (ADC) or auto‐transfer‐hydrogen (ATH) reactions of amines with alcohols to imines and secondary amines. Such selectivity could be controlled by the choice of alkali metal ion associated with the base. Under similar catalytic conditions, the ADC cross‐coupling of diamines with primary alcohols or diols afforded the corresponding benzimidazoles and quinoxalines in good to excellent yields. This catalytic system displayed good activity, recyclability, and wide applicability to a diverse range of substrates. Mighty fine ruthenium: Ruthenium nanoparticles (NPs) embedded in nitrogen‐doped carbon (Ru/N−C) were prepared by the pyrolysis of cis‐Ru(phen)2Cl2 loaded onto carbon powder. Ru/N−C NPs selectively catalyzed coupling reactions of amines with alcohols to imines and secondary amines, which could be controlled by the choice of alkali metal ions associated with the base. This catalytic system also displayed high activity towards cross‐coupling of diamines with primary alcohols or diols to yield benzimidazoles and quinoxalines. [ABSTRACT FROM AUTHOR]