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In this novel attempt to enhance the removal of oils and organic solvents from wastewater, making water safer and cleaner for use, poly(ethylene-co-vinyl acetate was blended with organically modified montmorillonite (OMMT) nanoclay following a green pathway by melt blending in a Brabender plasticoder. The prepared nanocomposites exhibited excellent adsorption capacity for various oils and organic solvents. To further increase the adsorption capacity of the nanocomposites, NaCl was added as a porogen in the melt mixing process, followed by the leaching of NaCl in water to generate a highly porous nanocomposite material. The adsorption tests revealed excellent efficiency, with an adsorption capacity of 40 g g−1 in dichloromethane (DCM), 11 g g−1 in gasoline, and 5 g g−1 in crude oil. The nanocomposites demonstrated excellent recycling capability and could be reused for more than 30 adsorption–desorption cycles. FTIR, XRD, SEM, and TEM analyses were conducted to delineate the structure and morphology of the nanocomposite. [ABSTRACT FROM AUTHOR]

We report the synthesis of a heterogenous silver catalyst stabilized by bidentate N-heterocyclic carbene ligands. The heterogeneous nature of the catalyst is inherently derived from the unprecedented internal structural features observed for the catalyst. X-ray studies show that the silver complex forms a two-dimensional cross-linked system, where one dimension of the network is formed by inorganic polymer strings and the second direction is formed by the interconnection of these inorganic strings with NHC bidentate ligands. This organized internal arrangement renders the complex insoluble in many common organic solvents and enables its utilization as a reusable heterogeneous catalyst in multicomponent A3 coupling reactions. Notably, propargylic amines were obtained with yields of up to 97%, and the catalyst demonstrated reusability for six cycles. These results can facilitate the further development of heterogeneous NHC catalysts. [ABSTRACT FROM AUTHOR]

Cu complex inks are composed of Cu salts as metal precursors and complexing agents that effectively reduce the decomposition temperature of the Cu salts. The thermal decomposition of the complexed Cu salt provides the metal for the in situ formation of nanoparticles. Using Cu formate tetrahydrate as a metal precursor, the effect of the complexing agent, i.e. amino-2-propanol and hexylamine, its molar ratio compared to the Cu salt, the predrying and sintering parameters such as temperature and ramp rate, and additional organic solvents are investigated to understand the influence on the morphology of the in situ generated Cu nanoparticles. The additional solvents are used to adjust the viscosity for ink-jet printing and to control the formation of the nanoparticles. A pre-drying step with a slow ramp rate (5 °C min−1) is required before the sintering process to effectively control the evaporation of organics. However, the slow pre-drying process leads to the growth of in situ generated particles into the microscale range (2–5 μm). Adding polyethylene glycol 600 (PEG600) is observed to suppress the growth of nanoparticles and realize an ink-jet printable formulation, which is achieved even with low Cu content (<8 wt%) and dense and homogeneous traces with a bulk resistivity of 20.48 μΩ cm when sintered in a conventional oven for 5 min at 250 °C under a N2 atmosphere. [ABSTRACT FROM AUTHOR]

The sensing of organic solvents and the determination of their water content are necessary conditions for ensuring environmental safety and organic solvent use. Herein, we selected a water-stable Cd-MOF, possessing 2D layers and amine groups, and optimized the synthesis conditions. The intensity of emission peaks gradually weakens with the increase in excitation wavelength in the range of 290–350 nm. The luminescent emission peaks exhibits a significant red shift with an increase in excitation wavelength at 355–400 nm. Tetrahydrofuran (THF) can significantly enhance the luminescent intensity of Cd-MOF compared to the others. Even in the presence of 5% volume fraction of other solvents, THF still shows a strong enhancement effect. These results confirm that this Cd-MOF can quickly and selectively detect THF through luminescent "turn on". Furthermore, the emission intensity of the Cd-MOF in THF gradually recedes with the increase in water, indicating its potential for the determination of water content of THF. The corresponding limit of detection is 0.14%, lower than that of some reported compounds. The interaction of THF and the amine groups of the ligand may lead to this specific enhancement of luminescence. In addition, the mixed matrix membrane with the functionality of MOF materials and the processability of polymers was synthesized, which can detect Fe3+, CrO42−, and Cr2O72− in water. [ABSTRACT FROM AUTHOR]

The study reported herein describes the synthesis of benzothiadiazole(BTD)-N-heterocycle derivatives by metal-catalyzed cross-coupling reactions with relatively good yields. The photophysical characteristics of these derivatives were assessed in solution through UV-vis absorption and steady-state fluorescence emission spectroscopies. These compounds show absorption maxima in the violet to blue region, related to spin and symmetry-allowed 1π → π* electronic transitions. The BTDs display fluorescence in the visible region of the electromagnetic spectrum, depending on their chemical structure and solvent, ranging from 499 to 570 nm. It was demonstrated that both ground and excited states are influenced by the substituents in the BTD core. In addition, a proof of concept was presented using these compounds as sensors for water in an organic environment. Theoretical calculations data provided a comprehensive insight into the structural and electronic factors that govern the photophysical behavior of these compounds. Solvent-induced twists result in a blueshift in the UV-vis spectra. The molecular electrostatic potential (MEP) provides insights into interactions, revealing that the addition of water influences both emission and molecular structure. [ABSTRACT FROM AUTHOR]

A novel porous metal–organic framework Co(btc)(bpy) (Co-MOF-3a) was synthesized by employing a bipyridyl ligand, benzene tricarboxylic acid, and Co(NO3)2·6H2O and was completely characterized. The mesoporous nature of the MOF catalyst was confirmed using BET measurements. The confirmation of the proposed structure of Co-MOF-3a was also supported through a computational study. This MOF could serve as a highly efficient heterogeneous catalyst for the oxidation of a variety of alcohols with tert-butyl hydroperoxide (t-BuOOH) as an oxidant. Furthermore, the current catalytic approach facilitated the oxidative coupling reaction in one pot to obtain a wide range of biologically important molecules, such as benzimidazole, benzothiazole, quinozolones, and arylidene malononitrile. The high performance of the MOF could be due to the presence of both the metal and carboxylate group of the ligand. The recyclability and scalability of the catalyst was found to be efficient and suitable for commercial applications. [ABSTRACT FROM AUTHOR]

Hypochlorite (ClO−) is closely involved in human health and environmental safety. Therefore, it is of vital importance to realize the detection and separation of ClO−. Herein, a nanoprobe with analysis and removal capabilities of ClO− was synthesized via immobilizing coumarin-based functional molecules on halloysite nanotubes. The probe can easily detect ClO− in aqueous solution without the need for organic solvents, showing a fast detection time (10 s), a wide pH range (4–11), a low detection limit (8.4 nM), and a credible recovery rate range of 93.6–105.1%. The probe was further prepared into convenient test papers to realize the visual detection of ClO−. More importantly, it also enabled the removal of ClO−, and the removal rate was as high as 99.6%. [ABSTRACT FROM AUTHOR]

Copper-1,3,5-benzenetricarboxylic acid (Cu–BTC) is a research hotspot for metal–organic frameworks (MOFs) because of its remarkable intrinsic structural features. However, the water instability issue has restricted its practical applications, such as capturing organic contaminants from wastewater. Herein, a novel Cu–BTC(OMe) was achieved through a convenient hydrothermal synthesis method with the partial group substitution of carboxyl with methoxy (OMe). The Cu–BTC(OMe) possesses good water resistance and exhibits excellent capturing performances toward methylene blue (MB) and tetracycline (TC). The adsorption process can be perfectly described by the Langmuir model and the pseudo-second-order kinetic equation. Importantly, Cu–BTC(OMe) is sustainable and stable, maintaining more than 90% of the initial MB and TC uptakes after recycling five times. In brief, grafting the OMe in the structure of Cu–BTC(OMe) could effectively boost its water stability and is favorable for synchronous MB and TC capture abilities. [ABSTRACT FROM AUTHOR]

Lignin is the largest renewable source of aromatic compounds, creating an opportunity for the chemical industry as a feedstock provided that the deconstruction and upgrading methods become economically feasible. Lignin valorization is performed using superoxide radicals (˙O2−) as an oxidizing reagent, which are electro-generated in situ through the oxygen reduction reaction (ORR) in an aprotic ionic liquid [BMIM]BF4. In this study, both the current efficiency and the percent conversion of lignin valorization are improved by simply reducing the viscosity of the electrolyte. The electrochemical analysis and molecular dynamics (MD) simulation results indicate that the presence of non-proton organic solvent CH3CN in [BMIM]BF4 can significantly improve the mass transfer process of O2, thereby accelerating the generation rate of ˙O2−. It is verified using p-benzylethoxyphenol (PBP) as a lignin model compound with a higher Faraday efficiency of 35.3% in [BMIM]BF4/CH3CN (7 : 3 v/v) than that of 15.5% in pure [BMIM]BF4. Finally, an actual lignin sample in [BMIM]BF4/CH3CN exhibited a percent conversion of 50.3% to selectively obtain only 4 kinds of the main small molecule aromatic compounds. [ABSTRACT FROM AUTHOR]

Understanding the forces governing hydrophobically driven inclusion provides a path for aimed utilization of non-polar synthons and provides insights into the related hydration thermodynamics. To shed light on the factors that determine the stability of complexes with large, rigid guests, we studied the temperature and the solvent effect on the hosting of diamantane alcohols with heptameric and octameric cyclodextrins and cucurbiturils. The smaller cyclodextrin was a more efficient binder of the explored guests, while inclusion within γ-CD was observed solely in water. The higher stability of β-CD complexes in this solvent (298 K) was due to the strongly exothermic, entropically opposed inclusion, whereas endothermic hosting of alcohols by γ-CD was observed in all cases except for diamantan-1-ol. The entropically more demanding dehydration of the β-CD cavity hence masks the positive entropy changes accompanying the removal of guest-hydrating water. A strong decrease in ΔrH°(T) for all studied systems was noticed in water. In the case of cyclodextrins, the phenomenon shifts the driving force from completely or predominantly classical towards non-classical. Conversely, due to the particularly poor structuring of cucurbituril-confined water, the binding remained essentially non-classical over the explored temperature range. Unlike complexation in water, the complexation in formamide and ethylene glycol was entirely enthalpy-driven and weakly temperature-dependent. [ABSTRACT FROM AUTHOR]

Two new 3D Cd(II)-MOFs have been constructed from a tetrakis(4-carboxybiphenyl)ethylene ligand, namely [Cd4.25(tcbpe)3]·0.25(C4H11N)·7.5DEF (NLMOF-1) and [Cd2K(H2tcbpe)(Htcbpe)]n·4DEF (NLMOF-2). Single-crystal X-ray analysis revealed that NLMOF-1 is of 3D framework constituted by 1D metal chains containing six-nuclear secondary building units (SBUs) and one-dimensional channel, while NLMOF-2 also exhibits a 3D structure in which the 1D channel is blocked by coordinated K ions, resulting in poor chemical stability. NLMOF-1 possesses excellent stability in both water and common organic solvents, conducive to investigating its utility as a chemical sensor. Fluorescence sensing studies show that NLMOF-1 is characteristic of highly sensitive and selective quenching effects toward Fe3+ ions in DMF, DMA, and acetonitrile, as well as MnO4− ions in H2O, DMA, and acetonitrile. The above results suggest that NLMOF-1 can be considered a potential fluorescent sensor for detecting Fe3+ and MnO4− ions. [ABSTRACT FROM AUTHOR]

Fluorescent carbon dots (CDs) with narrow emissions have been mostly prepared at high temperatures and high pressures, with long reaction times and tedious purification processes, which greatly limits their large-scale production. In contrast, the microwave-assisted solvothermal method can produce CDs simply and rapidly, but often results in wide-emissive CDs with full widths at half maximum (FWHM) larger than 80 nm. In this study, the microwave synthesis of CDs was improved by using ethylene glycol as the solvent and sodium thiosulfate as the oxidant. Consequently, narrow emissive CDs with a FWHM of only 35 nm were obtained from phloroglucinol, and were purified by simple precipitation using a mixed solvent of ethanol and dichloromethane. The structural characterization studies of the obtained CDs reveal that the sulfur element could be doped in the carbon structure with the addition of thiosulfate. It was also demonstrated that the photoluminescence efficiency of the CDs is greatly determined by their carbon core structures and edge groups. In addition, the fluorescence of CDs could be tuned significantly from the blue region to the green region by changing the dispersing solvent. Accordingly, the prepared CDs were successfully applied for the sensing of water content in organic solvents. [ABSTRACT FROM AUTHOR]

The preparation of new fluorescent cyclotriphosphazene compounds and examination of the effect of the substituent on the photophysical properties of the new compounds formed in terms of the number and variety of substituents are attempted in this work. Therefore, cyclotriphosphazene derivatives bearing carbazole and indole moieties (2–9) were synthesized via the nucleophilic substitution reactions of cyclotriphosphazene (1) with N-(2-hydroxyethyl)carbazole (I) and 1-(2-hydroxylethyl)-2-methyl-1H-indole (II) and those of tris nongeminal cyclotriphosphazene derivatives (3a,b and 5a,b) with I and II. The full characterization data of compounds 2–9 were obtained by utilizing mass spectrometry and spectroscopic techniques. The crystal structures of II and 3a were elucidated using the single crystal X-ray diffraction method. The photophysical aspects of the targeted compounds (7a, 8 and 9) were investigated by UV/Vis and fluorescence spectroscopies using different organic solvents, and the results for the targeted compounds were compared within themselves, together with their precursors (I and II). It was seen that compound 7a, which includes both an ethoxycarbazole and an ethoxymethylindole group, has improved photophysical properties when compared with the fully ethoxycarbazole (8) and fully ethoxymethylindole (9) substituted cyclotriphosphazene derivatives. [ABSTRACT FROM AUTHOR]

Self-buffering and biocompatible ionic liquids (ILs) derived from biological buffers, such as Good's buffers, have been recognized as potential innovative green agents for many practical applications. In order to develop their processing technologies, the thermophysical properties and molecular interactions of the binary systems containing tetramethylammonium 4-(2-hydroxyethyl)-1-piperazinepropanesulfonate ([TMA][EPPS]) with water, methanol or ethanol were investigated in this work. The densities and viscosities of the binary systems were measured at temperatures from 283.15 K to 333.15 K and concentrations from 0.342 mol kg−1 to 2.048 mol kg−1 under atmospheric pressure. The thermal expansion coefficients, the apparent molar volumes, and the solubilities of [TMA][EPPS] in water, methanol or ethanol at 298.15 K were also estimated from the experimental results of density measurements. The viscosity data of the ionic liquid solutions were correlated accurately with the Vogel–Fulcher–Tammann (VFT) equation. Moreover, the dissociation process and the solvation behavior of [TMA][EPPS] and its constituent ions in water, methanol, and ethanol were studied by using the COSMO-RS-based quantum calculations. The molecular interactions of the TMA cation, EPPS anion, or [TMA][EPPS] with solvent molecules (water, methanol, and ethanol) were also studied using DFT calculations. As a result, this IL derived from biological buffer has the ability to dissolve in water and organic solvents such as methanol and ethanol. This implies that these kinds of ILs are expected to have wide applications, not only in aqueous solution but also in organic solvent mixtures. [ABSTRACT FROM AUTHOR]

The activation of a dibromo Co-terpyridine complex immobilized on a stationary phase (Co(tpy)Br2@SiO2) as a hydrosilylation catalyst was investigated. Inorganic salts that are sparingly soluble in an organic solvent were examined as activators, and K2CO3 was found to show advantages in activator ability, stability, cost, and ease of handling. Catalytic hydrosilylation using Co(tpy)Br2@SiO2 activated by K2CO3 afforded the products in good yield, in both the reactions of styrene with triethoxysilane (92%) and 1-octene with diphenylsilane (88%). Both Co(tpy)Br2@SiO2 and K2CO3 were easily separable from the hydrosilylated product, which contributed to achieving a reusable hydrosilylation system in both the catalyst and activator. Moreover, the Co(tpy)Br2@SiO2/K2CO3 system was found to be applicable in a continuous flow reactor as a catalyst in the stationary phase. [ABSTRACT FROM AUTHOR]

Hierarchical porous metal–organic framework catalysts were synthesized by ligand regulation in an ionic liquid/ethanol system for the first time. The porosity and morphology could be tuned by the mass fraction of ionic liquid/ethanol and ligand. The hierarchical porous metal–organic framework catalysts exhibited very high activity and stability for the oxidation of alcohol. [ABSTRACT FROM AUTHOR]

This study adopted a one-pot method to prepare a composite solution, which uses Polyvinyl Alcohol (PVA) as the matrix, silanation-modified carbon nanotubes (S-CNTs) as the conductive mediators, dimethyl sulfoxide (DMSO) aqueous solution and glycerol as the organic solvent, and finally the composite solution was repeatedly freeze-thawed to prepare a composite hydrogel. By controlling the addition amount of S-CNTs, its effect on the properties of the composite hydrogels was investigated. The microstructure, mechanical properties, and electrical properties of the composite hydrogel were characterized and the results showed that the S-CNTs-0.3/PVA hydrogel had good mechanical properties (tensile strength: 0.53 MPa, tensile modulus: 410 kPa, toughness: 0.97 MJ m−3 and elongation at break: 294.81%) and excellent self-recovery performance. The assembled sensor can monitor finger bending and strain occurrence, indicating its potential application in human motion monitoring energy-sensing devices. [ABSTRACT FROM AUTHOR]

As a green adhesive, lignin-based acrylate adhesives have a promising future in substitute commercial adhesives owing to their cost-effectiveness, and environmental friendliness. In this work, a green and convenient strategy for the fabrication of lignin-based acrylate adhesives was developed via the introduction of lauryl methacrylate with a low glass transition temperature (−62 °C) into the chemical structure of lignin to improve the compatibility, toughness, strength and wettability of lignin-based adhesives. With the introduction of lauryl methacrylate, the shear strength of the lignin-based adhesive reached 5.10 MPa, which is 114% higher than the traditional acrylate adhesive. Moreover, the lignin-based adhesive also exhibits excellent hydrophobicity and high shear strength after 12 h of immersion in water. This work not only provides a new strategy for the fabrication of economical, green, and sustainable lignin-based acrylate adhesives without the participation of organic solvents, but also achieves the value-added utilization of lignin. [ABSTRACT FROM AUTHOR]

Chiral polymers always have the edge over their achiral analogues owing to the effective utilization of asymmetry to mimic nature in multiple ways. Chirality in tandem with conjugation in polymers creates an excellent platform for optoelectronic properties, leading to futuristic applications based on chiral photonics. Herein, we design two symmetric bis-functionalised phenylalanine tethered chiral diacetylene (DA) monomers that exhibit efficient topochemical polymerization into conjugated ene–yne polydiacetylene (PDA) with an intense red colour. The efficacy of the photopolymerization can be modulated by altering the peripheral functional groups. Interestingly, the individual enantiomers and their mixture show comparable photopolymerization owing to co-assembly. However, the chiroptical properties of the mixtures can be tweaked by the enantiomeric excess complying with the majority rule principle. Finally, the individual chiral PDA exhibits visible changes in optoelectronic and chiroptical properties under external perturbation e.g. temperature, volatile organic solvent and pH, that are investigated using UV-visible and circular dichroism spectroscopy. Such topochemical polymerization assisted by ordered self-assembly in peptide-tethered diacetylene provides convenient access to smart, responsive, chiral optoelectronic materials. [ABSTRACT FROM AUTHOR]

In this study, the first examples of bis-adduct BODIPY-C60 derivatives bearing glucose moieties as targeting unit were synthesized as heavy-atom-free triplet photosensitizers. Synthesized molecules were characterized via mass, 1H and 13C NMR spectroscopy techniques. UV-vis absorption and fluorescence emission spectroscopies were used to determine the photophysical properties of the developed photosensitizers. Singlet oxygen generation (1O2) capacities of the bis-adduct BDP-C60-1 and BDP-C60-2 dyads were investigated via both direct and indirect methods in organic solvents, whereas the singlet oxygen quantum yields were calculated as 60% for BDP-C60-1 and 55% for BDP-C60-2. The dyads were also used as heavy-atom-free triplet photosensitizers for the photooxidation of ABDA via the photosensitizing of 1O2 in aqueous media. Hence, it was determined that the new triplet photosensitizers were quite capable of generating singlet oxygen in both dichloromethane and aqueous media. The results are compared to those of the mono-adduct BODIPY-fullerene dyad systems. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) have received extensive attention in the extraction of natural products in the last few years. They are considered a substitute for conventional organic solvents because of their environmental advantages. To efficiently extract bioactive polyphenols and triterpenoids from the medicinal plant Celtis sinensis, fifteen DESs were prepared. The resulting DES1 (choline chloride-levulinic acid) showed the maximum extraction yield of total polyphenols, while DES9 (choline chloride-1,2-propylene glycol) had the maximum yield of total triterpenes. Further, the extraction conditions of DES1 and DES9 were methodically optimized. After optimizing the extraction conditions of DES1 and DES9, the extraction yield of total polyphenols was enhanced from 82.05 mg g−1 to 101.38 mg g−1 and that of total triterpenes from 57.87 mg g−1 to 72.72 mg g−1, both significantly superior to those of traditional water- and methanol-based extraction approaches. We designed a new DES by mixing DES1 and DES9 in the ratio of 7.25 : 2.75 to perform extraction of both polyphenols and triterpenes with high efficiency. The new DES solvent simultaneously increased the extraction yields of polyphenols and triterpenes to 118.46 mg g−1 and 88.51 mg g−1, respectively, after response surface methodology. More importantly, the extract obtained by the mixed solvent of DES1 and DES9 displayed significant antioxidant activity superior to those of extracts individually produced by DES1 and DES9. Our results indicate that a DES-based approach has promising potential in extracting bioactive substances from medicinal arbor species with high efficiency and eco-friendliness. [ABSTRACT FROM AUTHOR]

A one-step condensation procedure in the presence of green solvent EtOH was used to make a pyrene-based fluorescent sensor (PNPD). It could be used as a rapid, low-cost, selective, and sensitive chemodosimetric probe to detect water content. PNPD showed a cyan-blue emission in the presence of water due to cleavage of the imine bond, thus giving back the emission of pyrene carboxaldehyde. It displayed a relative error percentage of less than x ± 0.5% for the percentage detection of water content with noticeable DL and QL as compared to the reported works. A normalised approach was also developed to address the lack of knowledge in the quantitative detection of water content in an unknown sample. This approach can be used with any solvents and instruments, making it a quick, cost-effective, sensitive, and selective water sensing technique. The findings revealed that PNPD can detect water in polar, non-polar, protic, and aprotic solvents, with the detection limit and quantitation limit preferring polar aprotic solvent ACN and dioxane in both higher and lower water content. Also, we have developed a method for quantitative detection of water content in organic solvents by fluorescence studies. The real-time applicability of PNPD has been analysed by taking honey as an example, and a detection limit of 0.206 v% and quantitation limit of 0.624 v% have been found. [ABSTRACT FROM AUTHOR]

The focus of modern organic synthesis on the use of new sustainable and eco-friendly solvents emphasizes the need for understanding the correlation of structure and properties of these solvents to the reactivity in an organic transformation, thus enabling us to rationalize and predict the reaction outcome. Polarity is one such solvent property which is widely considered during drug design and synthesis; however, it cannot be characterized solely on the basis of one or more physical constants such as refractive index, relative permittivity, or dipole moment. Also, empirical determination of ET(30) parameter, which is an established benchmark for quantifying polarity is not only tedious but also time-consuming. In view of the spectacular development in the field of cheminformatics, we have resorted to computational tools to efficiently predict the empirical polarity of organic liquids with handful of structural features. In this report we have established a comprehensive database of wide diversity of 421 organic solvents using ET(30) parameters available in the literature, and quantum chemical and other descriptors calculated computationally. This dataset was employed to develop a statistically sound machine learning model with high predictive power. An artificial neural network architecture was found to be the best performing model amongst others screened in this study as suggested by R2 value of 0.96 and root mean square error of 1.29 for the test set. To the best of our knowledge, this is the first modelling approach that has been successfully used in predicting the empirical polarity of organic solvents on such a large dataset. [ABSTRACT FROM AUTHOR]

Anthocyanidins are one subclass of flavonoids in plants and possess important biological functions. They are not only natural and safe pigments, but also have various health-promoting effects for human. Dihydroflavonol 4-reductase (DFR) is a pivotal enzyme in the biosynthesis of anthocyanidins and other flavonoids in plants. DFR is responsible for catalyzing the reduction of dihydroflavonols to leucoanthocyanidins, which can be further converted into anthocyanidins by either enzymatic or chemical reactions. However, there are few studies on the efficient and green synthesis of anthocyanidins by in vitro biocatalysis currently. Here, we prepared magnetic Fe3O4/PVIM/Ni2+ nanoparticles as nano-carriers to immobilize a histidine-tagged DFR fusion enzyme acquired from the recombinant expression of the DFR gene of the tea plant. The DFR enzyme and the nano-carrier were connected based on specific affinity. The immobilization conditions were optimized. The nanoparticles and Fe3O4/PVIM/Ni2+-immobilized DFR enzyme were characterized by SEM, TEM, PSA, FT-IR, XRD and SQUID techniques. Compared with free enzyme, the immobilized DFR enzyme has better thermal stability, higher acid tolerance and relatively good reusability, and also reduces the inhibitory effect of metal ions and organic reagents on enzyme activities. This work developed a new nano-immobilized DFR enzyme that enriches the green synthesis method for the production of anthocyanidins. [ABSTRACT FROM AUTHOR]

As a fluorescent sensor for water over a wide range from low to high water content regions in organic solvents, we designed and developed a PET (photo-induced electron transfer)/AIE (aggregation-induced emission)-based fluorescent sensor EN-1 composed of a tetraphenylethene (TPE) core and four anthracene-(aminomethyl)-4-cyanophenylboronic acid pinacol esters (AminoMeCNPhenylBPin) as peripheral units. EN-1 showed an enhancement of the fluorescence band at around 450 nm originating from the anthracene skeleton with increasing the water content in THF in the low water content region below 1.0 wt%, which was attributed to the formation of the PET-inactive (fluorescent) species EN-1(H2O) by the addition of water molecules. With increasing the water content from 10 wt% to 50 wt%, the fluorescence intensity at around 500 nm originating from the TPE core gradually increased, which was attributed to the restricted intramolecular rotation (RIR) of TPE due to the increase in the viscosity of the THF–water mixtures. Furthermore, a significant enhancement of the fluorescence band at around 470 nm in the water content region above 60 wt% was observed due to the AIE characteristics associated with the aggregate formation of EN-1(H2O)-A in both PET-inactive and RIR states. The detection limit (DL) of EN-1 for water in the low water content region below 1.0 wt% in THF was 0.21 wt%, which was superior to that (DL = 0.49 wt%) of RS-1 composed of a TPE unit and an anthracene–AminoMeCNPhenylBPin unit. Moreover, the AIE characteristics of EN-1 were observed from the relatively low water content of 60 wt% compared with those of RS-1, which were observed in the high water content region over 75 wt%. The improvement of the DL value and AIE characteristics of EN-1 was ascribable to the fact that the four anthracene–AminoMeCNPhenylBPin units led to increased fluorescence emission originating from the anthracene skeleton and its low solubility in solvent–water mixtures, compared with RS-1. Consequently, this work reveals that EN-1 composed of a TPE core and four anthracene–AminoMeCNPhenylBPin units can act as a PET/AIE-based fluorescent sensor for the detection of water in a low water content region and from moderate to high water content regions in solvents. [ABSTRACT FROM AUTHOR]

In this article, solubility data are presented for the fluoro-monomer (meth)acrylate, which plays an important role as an organic solvent in several industrial processes. High-pressure phase equilibria for 1H,1H,2H-perfluoro-1-octene + supercritical CO2 (PFOe + Sc-CO2), and 1H,1H,2H,2H-perfluoro-1-octanol + Sc-CO2 (PFOl + Sc-CO2) models were assessed in a static device at different temperatures starting from 313.2 to 393.2 K and maximum pressure of about 17.22 MPa. Temperature–pressure (T–p) diagrams of the PFOe + Sc-CO2 and PFOl + Sc-CO2 systems show mixture-critical curves between the critical temperatures of CO2 and PFOe or CO2 and PFOl. The solubility of PFOe and PFOl in the two systems gradually increases with increasing temperature at constant pressure. The experimental curves for the PFOe + Sc-CO2 and PFOl + Sc-CO2 binary models show phase behavior of curve type-I. Correlations of experimental results for the PFOe + Sc-CO2 and PFOl + Sc-CO2 models are compared with the P–R EOS using mixing rules with two parameters (κij, ηij). The root mean squared deviation (RMSD) percentages (%) for the two systems using the optimum factors evaluated at 353.2 K were 2.19% for PFOl + Sc-CO2 and 5.30% for PFOe + Sc-CO2. The RMSD (%) for the PFOl + Sc-CO2 model evaluated by the alterable factor at each temperature was 2.78%. [ABSTRACT FROM AUTHOR]

This study presents the synthesis of a new phthalonitrile derivative, namely 4,5-bis(3,5-bis(trifluoromethyl)phenoxy)-3,6-bis(hexyloxy)phthalonitrile (1), and its mono metal {Zn (2), Lu (CH3COO) (3)}/double-decker lutetium (4) phthalocyanines. All the newly synthesized compounds were characterized by performing a series of spectroscopic methods encompassing 1H NMR, FT-IR, and mass spectroscopy. In addition, compounds (2–4) exhibited good solubility in different organic solvents. The antioxidant properties of compounds (1–4) were determined by applying a DPPH radical scavenging assay and using a spectrophotometer. The highest radical scavenging activity was obtained 95.7% at 200 mg L−1 for compound 2. The DNA nuclease activity of the newly synthesized compounds was investigated by performing the agarose gel method. All of the compounds exhibited DNA cleavage ability. Moreover, the antimicrobial activity of the tested compounds was studied using the microdilution and disc diffusion methods. The newly synthesized phthalonitrile and its metal complexes displayed antimicrobial photodynamic activity against E. coli. Additionally, the biofilm inhibition of the tested compounds was investigated and the highest biofilm inhibition was obtained 93.09% against P. aeruginosa for compound 3. [ABSTRACT FROM AUTHOR]

In this article, solubility data are presented for the fluoro-monomer (meth)acrylate, which plays an important role as an organic solvent in several industrial processes. High-pressure phase equilibria for 1H,1H,2H-perfluoro-1-octene + supercritical CO2 (PFOe + Sc-CO2), and 1H,1H,2H,2H-perfluoro-1-octanol + Sc-CO2 (PFOl + Sc-CO2) models were assessed in a static device at different temperatures starting from 313.2 to 393.2 K and maximum pressure of about 17.22 MPa. Temperature–pressure (T–p) diagrams of the PFOe + Sc-CO2 and PFOl + Sc-CO2 systems show mixture-critical curves between the critical temperatures of CO2 and PFOe or CO2 and PFOl. The solubility of PFOe and PFOl in the two systems gradually increases with increasing temperature at constant pressure. The experimental curves for the PFOe + Sc-CO2 and PFOl + Sc-CO2 binary models show phase behavior of curve type-I. Correlations of experimental results for the PFOe + Sc-CO2 and PFOl + Sc-CO2 models are compared with the P–R EOS using mixing rules with two parameters (κij, ηij). The root mean squared deviation (RMSD) percentages (%) for the two systems using the optimum factors evaluated at 353.2 K were 2.19% for PFOl + Sc-CO2 and 5.30% for PFOe + Sc-CO2. The RMSD (%) for the PFOl + Sc-CO2 model evaluated by the alterable factor at each temperature was 2.78%. [ABSTRACT FROM AUTHOR]

Metal persulfate mediated thermal oxidative organic transformations invariably require a higher temperature and frequently use an organic solvent. The objective of this work was to develop persulfate mediated oxidative transformations that can be performed nearly at room temperature using water as a solvent. This report describes modified Minisci aroylation of isoquinolines with arylglyoxylic acids using choline persulfate and its pre-composition (choline acetate and K2S2O8) in water at 40 °C. A few other nitrogen heterocycles were also utilized affording various aroylated products in good to excellent yields. Unlike metal persulfate that could produce metal salt byproducts, a key feature of the chemistry reported herein includes the use of environmentally benign choline persulfate containing biodegradable choline as a counter-cation, the Minisci reaction demonstrated at 40 °C in water as the only solvent, and unconventional activation of persulfate. [ABSTRACT FROM AUTHOR]

Despite the continuous development of heteroditopic molecular receptors with the ability to transfer salts from the aqueous to the organic phase as a symporter, the factors contributing to the effectiveness of these extractants are still unclear. One of those interplaying factors is the conformational freedom of the heteroditopic receptor. This receptor feature is traditionally thought to decrease the association energy due to energy expenditure of conformational changes during the complexation process. Herein we describe a series of heteroditopic carboxylate salt receptors that vary in the distances between the ion binding domains. Those receptors are based on α-ε-amino acids equipped with a 4-nitrophenyl urea group (anion binding domain) and N-(3-aminobenzyl)-aza-18-crown-6 (cation binding domain). The 1H NMR titrations (3% H2O/CD3CN) revealed high binding affinity and cooperativity for carboxylate potassium salts for receptors 1 and 2 whereas for more flexible receptors 3–5 weaker binding was observed. Under liquid–liquid extraction conditions the receptor 2 proved to be the most efficient extractant of highly hydrophilic KOAc salt. Unexpectedly, the receptor 4 weakly associating with KOAc under titration conditions proved to be only 18% less effective than 2 in an extraction process. The solution structures of ternary 2·KOAc and 4·KOAc complexes after an extraction process were studied by 2D ROESY experiments. Those studies suggest that the receptor 2 adopts a closed conformation while the receptor 4 displays a more open conformation. The compact structure of the 2·KOAc complex creates low polar entity, which is better stabilized in organic solvents and accelerates the extraction process. However, the open conformation of the 4·KOAc complex is still suitable for salt extraction. Thus the conformational freedom of heteroditopic receptors may lower the salt affinities but under extraction conditions it is compensated by the capability of better adapting to interphase conditions. [ABSTRACT FROM AUTHOR]

Molecular iodine contributes significantly to organic transformations in synthetic organic chemistry. It works effectively due to its mild Lewis acidic character, ability as an oxidizing agent, good moisture stability, and easy availability. It is non-toxic, cost-effective, non-metallic, environmentally benign, and has operational simplicity making it more popular for organic synthesis. In addition, many organic reactions show excellent stereo- and regio-selectivities within a short reaction time in common organic solvents. Previously, we reported the organic transformations catalyzed by molecular iodine up to 2012. In the present review article, we wish to highlight the significant and stringent achievements in molecular iodine catalyzed/promoted reactions from 2013 and onwards for researchers of chemistry, primarily during the last five years. [ABSTRACT FROM AUTHOR]

Anthocyanidins are flavonoids in plants with various biological activities and health-promoting effects. As plant-derived safe pigments, anthocyanidins have important economic values and broad applications. Dihydroflavonol 4-reductase (DFR) can catalyze dihydroflavonols into leucoanthocyanidins, which can turn into anthocyanidins through thermal incubation in n-butanol-HCl. However, studies on the enzymatic synthesis of anthocyanidins in vitro using recyclable nano-carrier immobilized enzymes have scarcely been seen until now. Here, we prepared magnetic Fe3O4–PEI-pMaltose nanoparticles and the recombinant DFR fusion enzyme with a maltose binding protein (MBP) tag. The DFR enzyme was immobilized on the Fe3O4–PEI-pMaltose nanoparticles based on the affinity adsorption under the optimum conditions of an enzyme/support ratio of 125 mg g−1, 20 °C, a pH of 6.5 and 25 min immobilization time. The sizes, morphologies, structures, and magnetic properties of the magnetic Fe3O4–PEI-pMaltose nanoparticles and the Fe3O4–PEI-pMaltose-immobilized DFR enzyme were characterized. The products from dihydroquercetin/dihydromyricetin catalyzed by the immobilized DFR enzyme or free DFR enzyme were both confirmed as cyanidin/delphinidin. Compared with the free DFR enzyme, the optimum reaction temperature and pH of the immobilized DFR enzyme were increased. The immobilized DFR enzyme possessed improved thermal and storage stabilities and enhanced tolerance to high pH conditions, and reduced the inhibitory effects of metal ions and organic solvents on the enzymatic activities. After four times repeated use, the activity of immobilized DFR remained above 85%. [ABSTRACT FROM AUTHOR]

Discharge of oily sewage causes serious environmental pollution and waste of resources, which can be solved by the process of oil/water separation. Polyurethane foam is a kind of promising candidate material for oil/water separation. In this work, a series of hydrophobic/lipophilic polyurethane foams were prepared by the in situ self-foaming method. The as-prepared polyurethane foams exhibited abundant open pore structures, excellent stability and superior hydrophobicity/lipophilicity. Thus, the as-prepared polyurethane foams can selectively absorb various oils/organic solvents from static and dynamic oil/water mixtures. The maximum absorption capacity for pump oil was up to 75.0 g g−1, and the separation fluxes were 1.5 × 106 L m−3 h−1 and 3.0 × 105 L m−3 h−1 for layered and turbulent oil/water mixtures, respectively. Moreover, the as-prepared polyurethane foams can separate the oil-in-water emulsions with a separation efficiency of >99% and a separation flux of 2.7 × 105 L m−3 h−1. The large-scale preparation of hydrophobic polyurethane foams by this method confirmed their potential in practical applications. [ABSTRACT FROM AUTHOR]

In this contribution, a new POM-based ionic liquid, namely (P6,6,6,14)4[W10O32], was fully characterized. Its viscosity and its very low dielectric constant make this hybrid ionic liquid suitable to be used as a solvent for organic transformations. As a proof of concept, this unique ionic liquid having both solvent and catalyst properties was tested for the catalytic oxidation of various alcohols and alkenes in the presence of H2O2. [ABSTRACT FROM AUTHOR]

Organogelators have received extensive attention in the recovery of leaked organic solvents or oil spills. However, due to the interactions of organogelators with the organic solvents/oil, the separation and recovery of organic solvents/oil and organogelators from organogels is difficult. In this study, we have developed an organogelator with pH-triggered recyclable property, realizing the recovery of oil and organogelator. The organogelator (HSA-N) is synthesized with 12-hydroxystearic acid (HSA) and 3-dimethylaminopropylamine by an amidation reaction. Here, HSA-N can gelate several organic solvents and fuel oils at a low concentration (less than 1 wt%), which is induced by the strong hydrogen bond interaction and van der Waals forces demonstrated by X-ray diffraction (XRD) and infrared spectroscopy (IR). As HSA-N can reversibly transform between hydrophilicity and hydrophobicity by regulating pH, the separation and recovery of organic solvents/oil and organogelator can be achieved at room temperature. Herein, organogelators with pH responsiveness make it promising to recover organic solvents/oil and organogelators from organogels at room temperature. [ABSTRACT FROM AUTHOR]

Simple ammonium ionic liquids [ILs] are efficient, green, environmentally friendly catalysts in promoting the Biginelli condensation reaction, Hantzsch reaction and Niementowski reaction to afford 1,2,3,4-tetrahydropyrimidine, 2-aminothiazole and quinazolinone derivatives respectively by eliminating the need for harmful volatile organic solvents. These [ILs] are air and water stable, easy to prepare and cost-effective. The effects of the anions and cations present in [IL] on reactions were investigated. The results clearly indicated that the Biginelli condensation reaction, Hantzsch reaction and Niementowski reaction were heavily influenced by the acidity of [IL], and among various ammonium ionic liquids, [Et3NH][HSO4] showed the best catalytic activity. Furthermore, [IL] could be easily separated and reused with a slight loss of its activity. This technique provided a good alternative way for the industrial synthesis of 1,2,3,4-tetrahydropyrimidinones, 2-aminothiazoles and quinazolinones. The present processes are eco-friendly methods for the synthesis of these derivatives authenticated by several green parameters, namely, E-factor, process mass intensity, reaction mass efficiency, atom economy, and carbon efficiency. [ABSTRACT FROM AUTHOR]

We prepared and characterized an array of polarity-sensitive fluorescent dyes (7 and 9a, 9b and 9c). Fluorescent dyes are based on imidazole cores, suitably functionalized with a conjugated push–pull system. The photophysical properties of the synthesized materials were elaborately investigated. These new fluorescent probes showed good fluorecence emission, higher φFl values and large Stokes shifts in different organic solvents because of their ICT nature. Furthermore, with aldehyde groups as the recognition sites, all the dyes could act as ratiometric fluorescent sensors towards methanol. The selective ratiometric fluorescence response towards methanol is due to the strong intermolecular H-bonding between the aldehyde unit and methanol. The detection limit of methanol was found to be at the ppm level. Methanol sensing was confirmed using emission spectroscopy, FTIR studies and theoretical calculations. Additionally, these dyes were used for the detection of methanol in biodiesel and in test paper strips. [ABSTRACT FROM AUTHOR]

Cyclic peptoids are biocompatible/biodegradable cyclooligomers constituted by N-substituted glycines showing high binding constants with the first group alkali metals (Ka ∼ 106 for Na+, Li+ and K+) in organic solvents. Three new metallated species bearing N-benzyl groups as side chains (a cyclic pentamer, [1·2Na]2+, and two cyclooctamer [3·Na]+ and [3·2Na]2+ peptoids) were synthesized together with the known N-perbenzylated sodiated cyclohexamer [2·Na]+ and [2·2Na]2+. Na+ complexes were investigated by means of spectroscopic (NMR), computational (DFT) and X-ray crystallographic studies. The first application of these complexes as catalysts in the ring opening polymerization (ROP) of L -lactide (L -LA) was examined. Our studies suggest that, for the intrinsic properties of the catalytic site (revealed by steric topographic maps) the homooligomeric pentamer complex [1·2Na]2+ is the most active member of the cyclooligomeric family. [ABSTRACT FROM AUTHOR]

The multicomponent synthesis of 1-amidoalkyl naphthols and polyhydroquinolines has been developed as an atom-economic procedure catalyzed by a deep eutectic solvent ([CholineCl][ZnCl2]3). The reactions proceed smoothly at low temperatures for a short reaction time without the use of toxic and volatile organic solvents. Deep eutectic solvents are capable of not only allowing multicomponent reactions to proceed in high yield but also controlling the selectivity towards desired products. The mechanistic insight was examined by HRMS (ESI) to propose a plausible mechanism. Furthermore, [CholineCl][ZnCl2]3 can be recycled in up to three consecutive cycles with an insignificant loss of catalytic activity under the optimized conditions. [ABSTRACT FROM AUTHOR]

Inflammation is associated with many different class of diseases and NSAIDs (non-steroidal anti-inflammatory drugs) are mostly preferred for long-term use. Although they are safe to use, some serious side effects are associated with these class of compounds; therefore, local drug delivery is an option to minimize the side effects. In this study, we have designed a new gel formulation for topical and transdermal applications of the NSAIDs with enhanced properties. For this purpose, low molecular mass DAP (2,6-diaminopyridine) derived fatty acid amides with varying alkyl chain lengths are synthesized. These fatty acid amides form stable self-assembled aggregates in organic solvents as well as in organic and aqueous solvent mixtures affording organogels and bigels, respectively. The minimum gelation concentration (MGC) of the organic gel is 0.5% w/v, which behaves as a super gelator. The various functionality present in the DAP-derived fatty acid amide gelators play an important role in the self-aggregation such as pyridine moiety stack through π–π and alkyl chain via van der Waals interactions resulting in the formation of stable organo and bigels network. The prepared organogel emulsions with these fatty acid amides are capable to encapsulate and release the drug molecule ibuprofen at room temperature without altering its structure and activity. Therefore, these analogues can be successfully utilized in pharmaceutical industries as a novel drug delivery carrier. [ABSTRACT FROM AUTHOR]

High-performance polyimides (PIs) with ether linkages and trifluoromethyl (–CF3) groups based on xanthene were designed and synthesized via a polycondensation reaction of novel diamine monomers with available aromatic dianhydrides. The structure of the synthesized compounds was confirmed by the 1H-NMR, FT-IR and elemental analysis techniques, and their photophysical attributes were studied by UV-vis and fluorescence spectroscopy. All the PIs demonstrated excellent thermal stability, glass transition temperatures (Tg) from 249 to 263 °C, char yields of greater than 37.9%, and 10% weight loss temperatures in a nitrogen atmosphere from 430 to 508 °C. Also, the inherent viscosities of the resulting polymers were in the range of 0.49–0.66 dL g−1. The PIs were completely soluble in polar amide-type organic solvents (NMP, DMAc, DMSO, and DMF) at ambient temperature. A polymeric nanocomposite (PI-a2/GO-HBP NC) was prepared by linking a polyimide (PI-a2) and hyperbranched aromatic polyamide-coated GO nanoparticles (GO-HBP NPs). The thermal stability, photoluminescence intensity, and antibacterial properties of the nanocomposite are higher than the neat polyimide due to powerful chemical links between the GO-HBP and PI-a2 chains. Also, all components were applied as efficient adsorbents for the elimination of chromium metal ions from aqueous solutions. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) as additives were used in the selective conversion of bio-based carbohydrates to 5-hydroxymethylfurfural (HMF) in this work. The effect of adding various imidazole-based ionic liquids with different anion structures on the production of HMF from fructose was firstly investigated in aqueous media. The presence of 15 wt% 1-butyl-3-methylimidazole chloride ([Bmim]Cl) ionic liquids in water with Fe2(SO4)3 as the homogeneous catalyst provided a more effective HMF synthesis compared to that without [Bmim]Cl addition. The enhanced HMF yield was mainly attributed to the fact that [Bmim]Cl might play a vital role in stabilizing the HMF molecule, which could thereby suppress side reactions involving HMF (e.g., its rehydration to levulinic acid or/and polymerization to humins). NMR and FTIR analyses suggested that such a stabilization effect stemmed from the interaction of [Bmim]Cl with the hydroxyl and aldehyde groups of HMF through hydrogen bonding. By performing the operation in a biphasic system (i.e., with the biomass-derived THF solvent as the organic phase and the addition of NaCl salt into water for improving HMF partition), the HMF yield over the Fe2(SO4)3 catalyst in the presence of the [Bmim]Cl additive could be further improved. The catalyst and ionic liquids were quite stable, and could be reused for more than five cycles with a consistent activity. A similar enhancement effect of [Bmim]Cl was also demonstrated in HMF synthesis with better yields from other biomass feedstocks or derivatives (including glucose, sucrose, cellobiose, inulin and starch) in aqueous media. [ABSTRACT FROM AUTHOR]

Using waste materials for the improvement of the properties of inexpensive, cost-effective, and readily available polymeric matrices can be an excellent idea. In the current work, the effect of activated carbon black (ACB) obtained from waste compact discs on the morphology, wettability, and pollutant sorption capacity of polyurethane (PU) sponge was studied. The water contact angles decreased from 122° for the pure PU to 109° for the obtained PU@ACB sponge composite. The potential sorption capacity of the samples for the uptake of tetrahydrofuran, chloroform, xylene, and n-hexane as organic solvents and kerosene as an industrial oil, as well as their separation ability for chloroform and edible oil from water, were investigated. According to the results and observations, the PU@ACB sponge composite exhibited higher sorption capacity than the pure PU. The outcomes revealed that the PU@ACB sponge composite demonstrated comparable or even better sorption capacity contrasted with other PU-based composites. [ABSTRACT FROM AUTHOR]

Oxime-based acetylcholinesterase reactivators are a specific group of drugs used for the treatment of organophosphate intoxication. However, high hydrophilicity and poor blood–brain barrier penetration limit their physiological potential. Cucurbit[7]urile (CB[7]) was used in this work as a potential carrier of oxime molecules to increase their treatment effectiveness. The host–guest chemistry of CB[7] with five clinically used oximes (trimedoxime, asoxime, obidoxime, pralidoxim and methoxime) and two new pre-clinical oximes (K027 and K048) was characterized under simulated physiological conditions using titration experiments with UV-vis detection. CB[7] forms stable complexes of 1 : 1 stoichiometry with all tested oximes. The decrease of complex stability was observed at a pH above the pKa of oxime, which limits the applicability of the complexation for oximes with pKa below the physiological pH. The combination of physiological ionic strength and pH causes partial decrease of the complex stability. The effect of organic solvent used in the sample pretreatment step before spectral analysis of oxime–CB[7] complexes in biological samples was demonstrated. Methanol is a more suitable solvent with low effect on complex stability. Finally, the ability of mass spectrometry with electrospray ionization was demonstrated for the analysis of oxime–CB[7] complexes. [ABSTRACT FROM AUTHOR]

DESs are new and greener alternatives to ionic liquids formed by mixing components that are capable of forming hydrogen bonds between them. The strong hydrogen bond interactions between the constituents make a large depression in the melting points compared to pure constituents. They are emerging as green solvents and have loomed as adorable alternatives to conventional organic solvents and ionic liquids with unique properties. In the present article, four new CeCl3·7H2O-based DESs were developed and their physical properties were studied. Their activities were checked in the Knoevenagel condensation reaction of dimedone/malononitrile with various aldehydes. The recyclability of the catalyst/solvent was achieved up to five runs without much change in the activity. [ABSTRACT FROM AUTHOR]

The optimization of the solubility in organic solvents of halogenated aza-dipyrromethenes was achieved by substitution of the upper phenyl moieties by branched long alkoxy chains (1f) or by using an OMe–OHex–OMe pattern (1h). These results allowed us to prepare original tetra-halogenated aza-dipyrromethenes that were used as a synthetic platform to access highly functionalized aza-bodipy dyes for various potential applications including PDT, imaging, or nonlinear optics. [ABSTRACT FROM AUTHOR]

We describe the synthesis of a range of 6′-triazolyl-dihydroxanthene-hemicyanine (DHX-hemicyanine) fused dyes through an effective copper-catalyzed azide–alkyne cycloaddition (CuAAC) "click" reaction, with the aim of providing molecular diversity and evaluating the spectral properties of these near-infrared (NIR)-active materials. This was implemented by reacting 15 different aliphatic and aromatic azides with a terminal alkynyl-based DHX-hemicyanine hybrid scaffold prepared in four steps and 35% overall yield from 4-bromosalicylaldehyde. The resulting triazole derivatives have been fully characterized and their optical properties determined both in organic solvents and under simulated physiological conditions (phosphate buffered saline containing 5% of bovine serum albumin protein). This systematic study is a first important step towards the development of NIR-I fluorogenic "click-on" dyes or related photoactive agents for light-based diagnostic and/or therapeutic applications. [ABSTRACT FROM AUTHOR]

An environmental-friendly and mild method has been successfully developed for the synthesis of 3-aryl-2-nitro-2,3-dihydrobenzofurans through domino Friedel–Crafts/substitution reaction of (Z)-bromonitrostyrenes with sesamol. A variety of substrates performed well in this reaction, and the corresponding 3-aryl-2-nitro-2,3-dihydrobenzofurans were obtained in excellent yields (up to 99%). Significantly, water served as the sole green solvent. Remarkably, the crude products were purified by simple filtration, washing with water and drying in oven without any organic solvents or silica gel. [ABSTRACT FROM AUTHOR]

Diaminomaleonitrile-based gelators 1 and 2, which describe the linking of diaminomaleonitrile as an H-bonding site to the cholesterol unit via an aromatic linker (naphthalene/benzene), have been synthesized. They form gels from various organic and aqueous organic solvents. Aggregation of the gelators occurs due to several weak forces (e.g., hydrophobic interactions, H-bonding and π-stacking interactions) in solutions. Compound 1 is a superior gelator as compared to 2 and is capable of forming gels from 15 out of the 20 solvents tested. The gelators show multiple applications. Toluene and 1,2-dichlorobenzene gels of 1 and 2, respectively, can sense F− and CN− anions by showing gel-to-sol transformation. These ions are distinguished with the aid of Fe3+. In the designs, changes in the linker group (naphthalene/benzene) influence the gelation behaviors and gel properties (mgc, thermal stability, morphology and mechanical behavior) of the gelators. The naphthyl analogue 1 exhibits self-healing behavior in contrast to the benzene analogue 2. Both 1 and 2 show phase-selective gelation (PSG) from biphasic mixtures of water and hydrocarbons/oils. The toluene gel of 1 serves as an excellent injectable material and has been applied in environmental remediation (e.g., oil spill recovery and removal of water-soluble toxic dyes). [ABSTRACT FROM AUTHOR]

Four dinuclear complexes: [Mn2(H2O)2(chdc)2(bipy)2], 1; [Co2(H2O)2(chdc)2(bipy)2]·H2O, 2; [Zn2(H2O)2(chdc)2(bipy)2]·H2O, 3; and [Cd2(H2O)2(chdc)2(bipy)2]·H2O, 4; chdc = e,a-cis-1,4,cyclohexanedicarboxylate and bipy = 2,2′-bipyridine, were attained as single crystals under ambient conditions. Crystallographic studies show that complexes 1, 2 and 3 are isostructural and crystallize in the monoclinic system with the P21/c space group. The metal centers in these complexes are hexa-coordinated with a distorted octahedral coordination sphere. Complex 4 crystallizes in the triclinic system with the P1¯ space group; in this compound, the metal centers are hepta-coordinated and their coordination sphere is distorted-capped trigonal prismatic. Magnetic property measurements reveal that complexes 1 and 2 exhibit weak antiferromagnetic ordering. Complex 4 displays solid-state blue emission properties and a highly sensitive response to acetonitrile in water based on turn-on fluorescence with a low detection limit of 1.1 μM and selectivity over common polar organic solvents. [ABSTRACT FROM AUTHOR]