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In the presented work, a study on the solubility and intermolecular interactions of l-serine and L-cysteine was carried out in binary mixtures of H 2 O + dimethylformamide (DMF), H 2 O + dimethylsulfoxide (DMSO), and H 2 O + acetonitrile (ACN) in the temperature range of T = 288.15 K to 308.15 K. l-serine exhibited the highest solubility in water, while L-cysteine was more soluble in water-DMF. The solvation process was assessed through standard Gibbs energy calculations, indicating the solvation stability order: water-ACN > water-DMSO > water-DMF for l-serine, and water-DMF > water-DMSO > water-ACN for L-cysteine. This study also explored the influence of these amino acids on solvent-solvent interactions, revealing changes in chemical entropies and self-association patterns within the binary solvent mixtures., Competing Interests: Declaration of competing interest The authors did not disclose any potential conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Polarity is a complex parameter, with important effect in chemistry and biology. In recent years, polarity exploration attracted more and more attention hence, it's of great importance to exploit new methods for polarity determination. A novel class of long, coplanar, and amine incorporated electron-rich quinoxaline scaffold(L 1 ) furnished maximum solvatochromic effect and large Stokes shift and was chosen to determine water content in organic solvents e.g. acetonitrile, THF, DMF, and methanol through fluorescence spectroscopy. Moreover, the probe was found to perform as an effective fluorescent sensor for the quantitative detection of low-level moisture content in four commonly-used organic solvents with low detection limits (0.018%, 0.027%, 0.012%, and 0.43% respectively). This study also describes the morphological transformation of L 1 form a fibrous network to spherical aggregates upon increasing water content in several organic solvents. Real-life implementation of the probe was successfully employed for the detection of moisture content in commercial food products and building materials such as cement, sand, limestone, salt, wheat, and detergent powder. Furthermore, probe L 1 -immersed easy-to-prepare test strips provide a reliable approach for qualitative monitoring of water content in organic solvents by a simple color-changing method under UV irradiation via smartphone-assisted RGB analysis., (Copyright © 2022 Elsevier B.V. All rights reserved.)

A novel D-π-A type fluorescent probe (probe 1) was developed for water content detection in organic solvents. By analyzing the relationship between fluorescence and water content, the probe was successfully applied to determine trace water content in tetrahydrofuran, ethyl acetate, 2-butanone, acetone, dimethylformamide, and acetonitrile. High water content in THF and ethyl acetate was associated with a gradual colour change from yellowish green to earthy yellow. The red/green value had a linear relationship with the water content in THF and ethyl acetate. There was a linear relationship between the red/blue value and water content in 2-butanone and acetone. Furthermore, probe 1 could be used for human serum albumin detection. Unexpectedly, probe 1 had a different colour response in deuterated and nondeuterated solvents, and had different fluorescence intensity and fluorescence emission wavelength. Probe 1 is rare tool that can distinguish between deuterated and nondeuterated reagents., (© 2022 John Wiley & Sons Ltd.)

Covalent organic frameworks (COFs) with good chemical stability, flexible chemical functionalization, tunable pore sizes, and high specific surface areas have been increasingly employed in the field of fluorescence sensing. In this work, a crystalline vinyl-functionalized COF TzDa-V was facilely prepared through a room-temperature synthetic method via condensation reaction between 4,4',4″-(1,3,5-triazine-2,4,6-triyl)trianiline (Tz) and 2,5-diallyloxyterephthalaldehyde (Da-V). The intermolecular charge transfer (ICT) effect endowed the TzDa-V with fluorescence characteristic, and it was sensitive to trace water and can be quenched due to the disruption of ICT process by water. On this base, the prepared COF TzDa-V with excellent chemical/thermal stability was applied to sensing of trace water in common organic solvents such as DMF, acetone, THF, and ethyl acetate with rapid response (less than 10 s), satisfactory sensing range (0.5-18% water in DMF, 0.5-15% water in acetone, 0.5-16% water in THF, 0.5-5% in ethyl acetate, v/v), and high sensitivity. The limits of detection for water in DMF, acetone, THF, and ethyl acetate were 0.0497%, 0.0590%, 0.0502%, and 0.0766% (v/v), respectively. The proposed probe was successfully used for the detection of trace water in food products such as salt and sugar. The COF TzDa-V would be a good candidate for application in water sensing., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Biocatalysis in mixtures of water and co-solvents represents an opportunity to expand the application of enzymes. However, in the presence of organic solvents, enzymes can undergo reversible inhibition, inactivation, or aggregation. In this work, we studied the effects of three co-solvents (methanol, acetone, and dimethyl sulfoxide - DMSO) on the function and structure of the recombinant Candida antarctica lipase B (rCALB), a widely used enzyme in biotechnological applications. The effects of co-solvents on rCALB were investigated by steady-state kinetics experiments, biophysical assays and by molecular dynamics simulations in the presence and upon incubation with the three co-solvents. Methanol and acetone were found to act as competitive inhibitors of rCALB and to promote its aggregation, whereas DMSO is a non-essential activator of rCALB., Competing Interests: Declaration of competing interest There are no conflicts of interest to declare., (Copyright © 2020. Published by Elsevier B.V.)

Dopamine (DA) polymerization has received significant attention in many fields, however, almost all of the works are limited to aqueous solution and hamper its wide application. This paper reports that amines can trigger DA polymerization by capturing the H + from DA hydrochloride and intermediates to accelerate the generation of radical species in water or organic solvents. Increasing concentration and decreasing pKb of amines cause the reaction equilibrium to shift toward the product polydopamine (PDA). Water-soluble and easily-removable Na 2 SO 4 nanowires and NaCl cubes can be used as templates to prepare different morphologies of hollow PDA structures by DA polymerization in ethanol solution. The carbonization production of PDA nanotubes at 900 °C (PDNC-900) is obtained and demonstrates electrochemical activity in the oxygen reduction reaction that is comparable to that of Pt/C., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Background: Biocatalysis in organic solvents is nowadays a common practice with a large potential in Biotechnology. Several studies report that proteins which are co-crystallized or soaked in organic solvents preserve their fold integrity showing almost identical arrangements when compared to their aqueous forms. However, it is well established that the catalytic activity of proteins in organic solvents is much lower than in water. In order to explain this diminished activity and to further characterize the behaviour of proteins in non-aqueous environments, we performed a large-scale analysis (1737 proteins) of the conformational diversity of proteins crystallized in aqueous and co-crystallized or soaked in non-aqueous media., Results: Using proteins' experimentally determined conformational diversity taken from CoDNaS database, we found that proteins in non-aqueous media display much lower conformational diversity when compared to the corresponding conformers obtained in water. When conformational diversity is compared between conformers obtained in different non-aqueous media, their structural differences are larger and mostly independent of the presence of cognate ligands. We also found that conformers corresponding to non-aqueous media have larger but less flexible cavities, lower number of disordered regions and lower active-site residue mobility., Conclusions: Our results show that non-aqueous media conformers have specific structural features and that they do not adopt extreme conformations found in aqueous media. This makes them clearly different from their corresponding aqueous conformers.

The translational diffusivity of covalent open‐[60]fullerene dimers in an organic solvent was found to be well describable by a prolate ellipsoid model while a monomeric open‐[60]fullerene behaves like a sphere model. The water association dynamics were examined for two open‐[60]fullerene dimers, showing a higher water affinity for the sp3‐linked dimer relative to sp2‐linked dimer owing to an effective orbital–orbital overlap identified by π(fullerene)→σ*(H2O) interactions as suggested by theoretical calculations. [ABSTRACT FROM AUTHOR]

Three types of 9,9-bis(4-hydroxyphenyl)fluorene-based diols reacted with 4,4′-difluorobenzophenone via nucleophilic substitution polymerization to afford the corresponding aromatic poly(ether ketone)s. The resulting polyketones have excellent solubility in typical organic solvents, such as THF, CHCl3, and NMP. They also have good thermal stability above 400 °C (Td10). In particular, the surface tension of the polyketone, which has four C4F9 groups per repeating unit, is 18.7 mN/m, which is equal to that of PTFE. The introduction of propylene linkers and many C4F9 groups per repeating unit was effective at improving water/oil repellency. [ABSTRACT FROM AUTHOR]

A trimer‐cyclisation reaction of propiolate esters yielded 1,3,5‐benzenetricarboxylate tri‐esters in water. The reaction proceeded selectively in the presence of secondary or tertiary amine salts in pure water solvent. Other organic solvents, such as dimethyl formamide, tetrahydrofuran, and ethanol, afforded a 1 : 1 adduct of propiolate and amine. The hydrogen bonding characteristics of water stabilised the proposed intermediate in a conformation that promoted the final cyclisation. The synthesis can be successfully conducted in water–a universal and an eco‐friendly solvent. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs), as a new class of crystalline, well‐ordered, and porous materials with intermittent constructions, are formed via organic structural parts connected through covalent bonds. These materials have been employed in several fields comprising pollutant adsorption and separation, catalysis, electrical conductivity, gas storage, etc. The preparation of COFs is mainly applied in tubes with high temperatures and degassing treatment. Furthermore, the reaction medium is involved in toxic organic solvents like toluene, dioxane, mesitylene, acetonitrile, and so on. Hence, discovering clean medium and green approaches has attracted wide attention. Recently, facile, less dangerous, and greener methods have been developed for COFs synthesis in diverse applications like performing the reaction at ambient temperature or employing aqueous solvents, ionic liquids, and a mixture of organic solvents/water. This review article summarizes the eco‐friendly production approaches of COFs for diverse applications. [ABSTRACT FROM AUTHOR]

In this work, we reported two nitrogen doped carbon quantum dot fluorescence sensors (Y‐CDs and R‐CDs) with good stability and luminescence efficiency, which can be quickly, sensitively and low‐cost for the determination of trace water content in organic solvents. Using o‐phenylenediamine and p‐phenylenediamine as nitrogen sources and terephthalic acid as carbon sources, the preparation was carried out through simple solvothermal synthesis and heteroatom doping. The luminescence characteristics and interaction mechanism with the target were discussed. The results indicate that the two carbon dots can effectively quench the water content in acetone, ethanol, and DMF, as well as physical interactions such as hydrogen bonding and dynamic quenching, which are the reasons for the observed quenching effect. Based on this, a new method for determining water content in organic solvents using carbon quantum dot fluorescence probes has been established. The linear relationship between the fluorescence quenching efficiency F0/F of two carbon quantum dots and the water content in different organic solvents was studied. The detection limits (LOD) of water in acetone, ethanol and N,N‐dimethylformamide (DMF) were 0.17 %, 2.35 %, 0.26 %, respectively, determined by Y‐CDs. The LOQ of acetone, ethanol, and DMF were 0.554 %, 7.83 %, 0.855 %, respectively. The LOD of water in acetone, ethanol and DMF determined by R‐CDs were 0.056 %, 0.69 %, 0.27 % and the LOQ was 0.187 %, 2.290 %, 0.909 %, respectively. Good recovery rates and precision were achieved in practical applications. [ABSTRACT FROM AUTHOR]

A straightforward, rapid, green, and efficient synthetic procedure has been introduced for easy access to the synthetically highly substituted arylideneisoxazol-5-(4H)-one products. A wide scope of the heterocyclic products was obtained via the three-component cyclocondensation of various aryl aldehydes, NH2OH·HCl, and β-dicarbonyls by zinc oxide nanoparticles (ZnO NPs) as the catalyst. Optimizing the reaction conditions indicated that a relatively small amount of catalyst was required and arylideneisoxazol-5-(4H)-ones were obtained in very short reaction times. Purification of synthesized heterocyclic molecules was carried out with the help of simple filtration and crystallization from ethanol. In this method, exhausting and expensive chromatography methods were not used to purify the products, and the use of organic solvents was also avoided. In addition, this method is important from the point of view of green chemistry. The simplicity of the method, cost-effective catalyst, less time-consuming, mild reaction conditions, conducting experiments at room temperature, as well as recyclability and reusability of ZnO nano-catalyst are among other advantages of this powerful process. [ABSTRACT FROM AUTHOR]

Reversible addition‐fragmentation chain transfer (RAFT) polymerization has proven itself as a powerful polymerization technique affording facile control of molecular weight, molecular weight distribution, architecture, and chain end groups ‐ while maintaining a high level of tolerance for solvent and monomer functional groups. RAFT is highly suited to water as a polymerization solvent, with aqueous RAFT now utilized for applications such as controlled synthesis of ultra‐high molecular weight polymers, polymerization induced self‐assembly, and biocompatible polymerizations, among others. Water as a solvent represents a non‐toxic, cheap, and environmentally friendly alternative to organic solvents traditionally utilized for polymerizations. This, coupled with the benefits of RAFT polymerization, makes for a powerful combination in polymer science. This perspective provides a historical account of the initial developments of aqueous RAFT polymerization at the University of Southern Mississippi from the McCormick Research Group, details practical considerations for conducting aqueous RAFT polymerizations, and highlights some of the recent advances aqueous RAFT polymerization can provide. Finally, some of the future opportunities that this versatile polymerization technique in an aqueous environment can offer are discussed, and it is anticipated that the aqueous RAFT polymerization field will continue to realize these, and other exciting opportunities into the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Cyclic polymer with amphiphilic nature is first investigated as fluorescence sensor. • The probe displays the vast potential for sensing of water in 10 organic solvents. • The broadest concentration range of water in N,N-dimethyl acetamide was achieved. • The mechanism was explored by theory and experimental investigation. A sensor capable of sensing of water in various organic solvents ranging from water-soluble to water-miscible solvents is still a challenging task. In this research, a cyclic polymer fluorescence chemosensor (CPFC) has been developed for sensing of water by turn-on model in 9 organic solvents and turn-off model in DMA, where the broadest concentration range and the lowest detection limit was obtained for water in DMA (10 %–90 %) and dioxane (0.011 %), respectively. The sensing mechanism is explored by theory calculation and experimental investigation. The amphiphilic nature endows the polymer probe with great potential for measuring various contaminants from aqueous and nonaqueous mediums. Furthermore, the present search highlights the potential applications of cyclic polymer as fluorescence probes in the field of sensing. [ABSTRACT FROM AUTHOR]

Using biomass-derived solvents in various organic reactions is challenging for the fine chemicals industry. We herein report a Pd/C catalyzed Suzuki–Miyaura reaction in water extract of suaeda salsa (WES) without using external phosphine ligand, base, and organic solvent. The cross-coupling reactions were carried out in a basic WES medium with a broad substrate scope and wide functional group tolerance. Furthermore, the high purity of solid biaryl products can be obtained by column chromatography or filtration. [ABSTRACT FROM AUTHOR]

Frontal polymerization is a relatively old polymerization process that is performed in a limited space and is done with a spontaneously progressive wave mechanism. This process is for quick and easy preparation of all types of polymers, co-polymers, nano composites, large composite parts. In recent years, it has been used to prepare polymer hydrogels. This study is an overview of frontal polymerization in the chemical industry. Hydrogels are a group of lattice polymers with a three-dimensional structure, which, due to their hydrophilic groups, are able to absorb large amounts of water and biofluids without dissolving. SO3H-in the structure of hydrogels. These materials can absorb from 10% to thousands of times their initial weight in the dry state of water. The water content of hydrogels plays an important role in determining the overall properties of the polymer network. For this reason, compared to hydrophobic polymer networks, hydrophilic hydrogels show different properties. Also, the preparation conditions of hydrophilic hydrogels are milder due to the formation of gels at room temperature and the rare use of organic solvents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Enthalpies of L- carnosine dissolution have been measured in some water-organic mixtures. • Dependence of L- carnosine solvation on the mixture composition is established. • Results are compared with similar for β-alanyl-β-alanine. • The enthalpic contribution of L- carnosine and β-alanyl-β-alanine side-chains to h xy were determined. • The enthalpy of L -carnosine solvation depends on the polarity and donor–acceptor properties of solvents. Isothermal calorimetry was used to measure the enthalpies of L -carnosine digestion in aqueous solutions of acetonitrile (AN) 1,4-dioxane (DO), acetone (AC), dimethyl sulfoxide (DMSO), ethanol EtOH), 1-propanol (1-PrOH), and 2-propanol (2-PrOH). The values of Δ sol H ° obtained were combined with the standard enthalpies of L -carnosine sublimation to obtain the corresponding enthalpies of solvation Δ solv H °. In addition, the enthalpic coefficients of pairwise interactions (h xy) of L -carnosine with organic solvent molecules and the enthalpy of transfer (Δ tr H °) from water in their mixture with the latter were calculated. It is established that the solvation of L -carnosine is weakened in a series of (H 2 O + EtOH) > (H 2 O + 1-PrOH) > (H 2 O + 2-PrOH). This may be due to an increase in the hydrophobicity of alcohols of the same order as well as the presence of CH 3 -groups within the alcohol molecule. The weakening of the solvation energy of L -carnosine by co-solvent molecules in a series of mixed solvents: (H 2 O + AN) < (H 2 O + AC) < (H 2 O + DO) < (H 2 O + DMSO) is associated both with an increase in the hydration energy of co-solvents in the same order and with their physicochemical properties. The enthalpic coefficients of water-organic solvent pairwise interactions were discovered to be linearly related to the corresponding coefficients of L -carnosine-organic solvent interactions. An increase in the polarity and acidity of an organic solvent increases the energy of pairwise interactions between L -carnosine and the organic solvent. Increasing the cohesion energy density, molar volume, and basicity of the organic solvent reduces the energy of the pairwise interactions between L -carnosine and the organic solvent. [ABSTRACT FROM AUTHOR]

Three new derivatives of (4-methoxyphenyl) ethynyl-naphthalimide were synthesized by Sonogashira coupling reaction. These compounds showed robust and strong fluorescent signals, which shift from blue to orange as the solvent polarity increases. Computational calculations revealed that in low-polarity solvents, the molecules preferred a 90° rotation between the naphthalimide and ethynyl benzene fragments. In high-polarity solvents, where the energy barrier for rotation of the alkyne bond was higher, the molecules favored the 0° conformer, leading to longer emission wavelengths. The compound with a 2-methoxyethyl group tethered to the naphthalimide nitrogen demonstrated sensitivity to water presence in the ranges of 0–30 % (v/v) in THF, 0–15 % (v/v) in DMSO, 0–30 % (v/v) in MeCN, 0–15 % (v/v) in acetone, and 0–40 % (v/v) in EtOH. The detection limits for water were determined to be 0.0523 %, 0.1365 %, 0.0337 %, 0.0570 %, and 0.1170 % (v/v) in THF, DMSO, MeCN, acetone, and EtOH, respectively. The effectiveness of this compound in quantifying ethanol content in spirit samples was successfully demonstrated. [Display omitted] • Three new naphthalimides exhibited strong fluorescence transitioning from blue to orange based on solvent polarity. • Computational calculations identified conformational preferences influencing emission wavelengths. • One of these compounds was effective for quantifying ethanol in spirit samples. [ABSTRACT FROM AUTHOR]

A water‐promoted synthesis methodology for constructing 3‐sulfone propionic acids from sulfonyl hydrazides and α, β‐unsaturated propionic acids with excellent yields were reported. The green synthesis methodology was promoted by water without any catalyst, ligand and organic solvent. The D2O control experiment sufficiently proved that the 2‐hydrogen atom of 3‐sulfone propionic acid come from water. Moreover, the 3‐sulfone propionic acid derivates could be directly purified by crystallization without column chromatography. [ABSTRACT FROM AUTHOR]

Molecular recognition processes in water differ from those in organic solvents in that they are mediated to a much greater extent by solvent effects. The hydrophobic effect, for example, causes molecules that only weakly interact in organic solvents to stay together in water. Such water‐mediated interactions can be very efficient as demonstrated by many of the synthetic receptors discussed in this review, some of which have substrate affinities matching or even surpassing those of natural binders. However, in spite of considerable success in designing such receptors, not all factors determining their binding properties in water are fully understood. Existing concepts still provide plausible explanations why the reorganization of water molecules often causes receptor‐substrate interactions in water to be strongly exothermic rather than entropically favored as predicted by the classical view of the hydrophobic effect. [ABSTRACT FROM AUTHOR]

Seeking a more environmentally balanced method of peptide synthesis, we are focusing on developing organic solvent-free synthetic methods using water, an environmentally friendly solvent. In current peptide synthesis, the most common building blocks are Boc- and Fmoc-protected amino acids, which are highly soluble in organic solvents. We previously reported a technique for solid-phase peptide synthesis in water that utilizes Fmoc-amino acids converted to water-dispersible nanoparticles. The Boc strategy is well-known to be suitable for the industrial chemistry and green chemistry, because only gases are generated without any other by-products in the deprotection step of Boc group. Here we summarize in-water both liquid and solid-phase method using Boc-amino acids based on MW-assisted coupling reaction of nanosized reactants, nanoparticles and nanomicelles. [ABSTRACT FROM AUTHOR]

[Display omitted] • A dual-emission fluorescent MOF has been synthesized based on the introduction of Eu3+ ions, into aluminum metal − organic frameworks. • The dual-emission Eu/Al-MOF is used to design the sensor for the quantitative detection of histidine and water by changing the independent fluorescence signals. • The Eu/Al-MOF has been successfully applied to the detection of histidine in urine samples. • The solid-state fluorescence of Eu/Al-MOF proves instrumental in visualizing and identifying fingerprints. Ratiometric fluorescent sensors possess inherent self-calibration features that enable the mitigation of interference from factors unrelated to the analysis. This characteristic results in heightened sensitivity and more pronounced visual detection during qualitative and quantitative analytical processes. A ratiometric fluorescence probe Eu/Al-MOF has been successfully prepared via Eu3+ doped aluminum metal − organic frameworks. Upon introducing histidine, the fluorescence intensity of Eu3+ showed a noteworthy increase, whereas the intensity originating from the ligand decreased owing to enhancing energy transfer from the ligand to Eu3+ ions in the probe. Eu/Al-MOF could detect histidine over a wider linear range of 0.1–400 μM and a lower detection limit of 0.04 μM. Besides, in the presence of water in organic solvents, the excited state of Eu3+ in the probe could be coupled with the O-H oscillation of water molecules, and the excited state energy from Eu3+ would be transferred to the water molecules so that only the fluorescence intensity of Eu3+ gradually decreased. Thus, the proportional detection of trace water could be realized. In ethanol and DMF, the detection range for water was 0.1–20 % and 0.5–20 %, respectively. Moreover, it was found that Eu/Al-MOF could efficiently achieve the visualization identification of fingerprints, providing the possibilities for applying the nano-sensor as a promising multifunctional fluorescence probe. [ABSTRACT FROM AUTHOR]

The first example of the sulfinylation of indoles with arylsulfinamides in water in the presence of trifluoroacetic acid as a promoter is described. The reaction occurs smoothly at room temperature under environmentally benign conditions without any catalyst, additive, ligand, or organic solvent. The developed sulfoxide synthetic protocol is attractive due to the use of water as the solvent and provides a novel and efficient route to a wide range of functionalized diaryl sulfoxides. [ABSTRACT FROM AUTHOR]

Imidazolium-based ionic liquids (ILs) represent a well-studied class of ILs. These compounds are characterized by many fascinating properties such as non-flammability, low vapor pressure, wide electrochemical window, and thermodynamic and kinetic stability. This review paper aims to provide an insight into some experimental methods of investigations and applications of these ILs. Additionally, some results on the topic of imidazolium-based ILs in various solvents are presented. [ABSTRACT FROM AUTHOR]

Molecular machines are ubiquitous in nature and function away from equilibrium by consuming fuels to produce appropriate work. Chemists have recently excelled at mimicking the fantastic job performed by natural molecular machines with synthetic systems soluble in organic solvents. In efforts toward analogous systems working in water, we show that guest molecules can be exchanged in the synthetic macrocycle cucurbit[7]uril by involving kinetic traps, and in such a way as modulating energy wells and kinetic barriers using pH, light, and redox stimuli. Ditolyl‐viologen can also be exchanged using the best kinetic trap and interfaced with alginate, thus affording pH‐responsive blue, fluorescent hydrogels. With tunable rate and binding constants toward relevant guests, cucurbiturils may become excellent ring molecules for the construction of advanced molecular machines working in water. [ABSTRACT FROM AUTHOR]

To develop highly efficient synthetic reactions is quite important in organic chemistry. Cross dehydrogenative couplings (CDC) utilize C−H bonds of substrates to construct new C−X (X=C, S, O, N, P) bonds. For CDC, the pre‐functionalization of reaction substrates can be avoided and the C−X (X=C, S, O, N, P) bonds can be newly formed by simple and efficient synthesis routes. Meanwhile, water is increasingly used as a substitute for organic solvents in cross‐dehydrogenative coupling because of its rich content, non‐toxicity, and non‐ flammability. In recent years, organic chemists are devoted their efforts to explore the cross dehydrogenative couplings (CDC) in aqueous phase which feature high atom utilization rate and environmental friendliness. Herein, we summarized the recent advances in the construction of C−C, C−S, C−O, C−N, and C−P bonds through CDC reactions of C−H bonds in water. [ABSTRACT FROM AUTHOR]

Self‐assembly by imine condensation in aqueous media is a formidable task because of the labile nature of imines in the presence of water. Here, by taking advantage of multivalence and ligand preorganization, basket‐shaped triscationic cage molecules are self‐assembled in high yields in both water and organic solvent, by condensing a hexaformyl and bisamine. These cages, especially the chiral ones, are stable or inert in aqueous solution, that is, no decomposition was observed upon dilution, precipitation, or exposure to competitive amines or aldehydes. Such water‐compatibility allows the hosts to take advantage of the hydrophobic effect to accommodate hydrophobic guests. The chiral cage S‐23+ selectively binds and distinguishes one of two enantiomers, opening up opportunities for applications such as chiral compound separation. Chiral narcissistic self‐sorting and sergeants‐and‐soldiers effects occur during cage formation when two amino precursors are involved in self‐assembly. [ABSTRACT FROM AUTHOR]

Metal‐bound water molecules have recently been recognized as a new facet of soft Lewis acid catalysis. Herein, a chiral palladium aqua complex was constructed that enables carbon–hydrogen bonds of indoles to be functionalized efficiently. We embraced a chiral 2,2′‐bipyridine as both ligand and hydrogen‐bond donor to configure a robust, yet highly Lewis acidic, chiral aqua complex in water. Whereas the enantioselectivity could not be controlled in organic solvents or under solvent‐free conditions, the use of aqueous environments allowed the σ‐indolylpalladium intermediates to react efficiently in a highly enantioselective manner. This work thus describes a potentially powerful new approach to the transformation of organometallic intermediates in a highly enantioselective manner under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Reducing or eliminating organic solvent use in pharmaceutical manufacturing is perhaps the most effective way to reduce the environmental, health, and safety impacts of drug substance manufacturing. With this in mind, we have developed a process to manufacture an investigational 5-HT4 receptor agonist that is conducted almost entirely in water, including multiple controlled isolations. Key transformations carried out in aqueous media include a benzimidazole cyclization, amide bond formation, reductive amination, and a selective oxidation of an aliphatic alcohol. Compared to the first-generation manufacturing process using organic solvents, the aqueous process described here uses 77% less material inputs, 94% less organic solvent, and, surprisingly, 48% less water, while improving overall yield from 35% to 56%. [ABSTRACT FROM AUTHOR]

Nitroaromatic compounds were massively used in the formulation of explosives during both world wars. Even several decades after the end of these wars, their residues are suspected to be widely present in the environment. Their occurrence and effect on ecosystems and human health are still not fully determined. This paper describes the development of a method for the determination of 28 nitroaromatic compounds in water, including isomers of nitrotoluene (NT), dinitrotoluene (DNT), trinitrotoluene (TNT), nitrobenzene (NB), dinitrobenzene (DNB), chloronitrobenzene (ClNB), chlorodinitrobenzene (DNCB), nitronaphthalene (NN), dinitronaphthalene (DNN), nitroaniline (NA), dinitroanisole (DNAN), diphenylamine (DPA), and nitrodiphenylamine (nitro-DPA). In order to separate and individually quantify all the analytes with the best possible sensitivity, stir bar sorptive extraction (SBSE) was chosen as the extraction and pre-concentration step prior to gas chromatography (GC) separation and tandem mass spectrometry detection (MS/MS). Our SBSE optimization efforts focused on parameters such as the type of stir bar, ionic strength, addition of organic solvent, and extraction and desorption times. After these optimizations, the analytical method enabled us to reach limits of quantification (LOQs) between 1 and 50 ng/L in tap water, groundwater, and surface water. The method was applied to the determination of targeted nitroaromatic explosive residues in spring and groundwater samples collected in an area where mine warfare had raged during World War I. Up to 16 different nitroaromatic compounds were detected in the same sample. The highest concentrations were recorded for 2,4-DNT and 1,3-DNB (1700 and 2690 ng/L respectively). [ABSTRACT FROM AUTHOR]

Water and the organic solvents tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, 1-propanol, 2-propanol, tert-butanol, acetonitrile, or acetone are completely miscible in all proportions at room temperature. Here, we present new buffering-out phase separation systems that the above mentioned organic aqueous solutions can be induced to form two liquid phases in the presence of a biological buffer 2-[[1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonic acid (TES). The lower liquid phase is rich in water and buffer, and the upper phase is organic rich. This observation has both practical and mechanistic interests. The phase diagrams of these systems were constructed by experimental measurements at ambient conditions. Molecular dynamic (MD) simulations were performed for TES + water + THF system to understand the interactions between TES, water, and organic solvent at molecular level. Several composition-sets for this system, beyond and inside the liquid-liquid phase-splitting region, have been simulated. Interestingly, the MD simulation for compositions inside the phase separation region showed that THF molecules are forced out from the water network to start forming a new liquid phase. The hydrogen-bonds, hydrogen-bonds lifetimes, hydrogen-bond energies, radial distribution functions, coordination numbers, the electrostatic interactions, and the van der Waals interactions between the different pairs have been calculated. Additionally, MD simulations for TES + water + tert-butanol/acetonitrile/acetone phase separation systems were simulated. The results from MD simulations provide an explanation for the buffering-out phenomena observed in [TES + water + organic solvent] systems by a mechanism controlled by the competitive interactions of the buffer and the organic solvent with water. The molecular mechanism reported here is helpful for designing new benign separation materials. [ABSTRACT FROM AUTHOR]

Eco-friendly and practical methods for the complementary regioselective synthesis of 3-(1-substituted pyrazol-3-yl) indoles and 3-(1-substituted pyrazol-5-yl) indoles, from DBSA-mediated regioselective cyclocondensation reaction of β-ethyltho-β-indolyl-α, β-unsaturated ketones and monosubstituted hydrazines in water through simply varying the appropriate reaction way, had been developed. The methods not only efficiently avoided the use of organic solvent but also exhibited attractive characteristics such as operational simplicity, broad substrate scope, easy separation of products and ease of scale-up. [ABSTRACT FROM AUTHOR]

A simple approach for producing supramolecular nanohybrids was developed allowing preparation of soluble hybrid two‐dimensional nanosheets in water through spontaneous organization of two‐dimensional Cu(II) rubeanate hydrate (which by itself does not dissolve in water or common organic solvents) and cationic diblock copolypeptide amphiphiles. These components self‐assembled into nanosheets with thicknesses of about several nm and widths on the order of several micrometers. Notably, the nanostructures were dependent on polypeptides containing leucine, suggesting that both cationic and hydrophobic polypeptide components are involved in generating the two‐dimensional (2D) nanosheet structures. The supramolecular hybrids exhibited excellent stability, and made it possible to control spectroscopic properties including ligand‐to‐metal‐charge‐transfer (LMCT), d‐d transition, electrochemical behavior, and electrooxidation reactions with ethanol in aqueous media. [ABSTRACT FROM AUTHOR]

A smartphone-based ratiometric fluorescence device was designed to monitor the reaction kinetic process under vigorous mixing conditions, demonstrated by the hydrolysis of Cs4PbBr6 nanocrystals (NCs). In the presence of trace water, part of Cs4PbBr6 NCs (non-fluorescent) was converted to CsPbBr3 NCs (strong fluorescent). Using anthracene as the reference fluorophore, the brightness ratio of the green (from CsPbBr3 NCs) to blue (from anthracene) components in the fluorescence image which was recorded in situ by the smartphone camera was measured as the signal for kinetic analysis. It was shown that the water-triggered conversion reaction from Cs4PbBr6 NCs to CsPbBr3 NCs follows the pseudo-second-order kinetic model in the early rapid hydrolysis stage (up to 4 min). With increasing water content, the hydrolysis of Cs4PbBr6 NCs is promoted to yield more CsPbBr3 NCs, which was used to determine trace water in n-hexane, dichloromethane, and toluene with detection limits of 0.031, 0.043, and 0.057 μL mL−1, respectively. The device offers the advantages of portability and low cost for rapid field determination of trace water in hydrophobic organic solvents. [ABSTRACT FROM AUTHOR]

Graphene has attracted much attention and holds great promise in various applications due to its extraordinary properties. To realize applications of graphene in large scale, developing a facile, green and cost-effective method for mass production of high-quality graphene is highly desired. Relative to expensive and complicated bottom-up approaches, top-down methods for graphene production are promising owing to their low cost and simplicity. Specifically, exfoliation of graphene nanosheets in liquid phase is favorable for their dispersion, functionalization and processing. Instead of highly toxic organic solvents, using water as the liquid medium makes exfoliation process eco-friendly and sustainable. In this review, recent progress on exfoliation of graphene nanosheets in water is discussed, with a particular focus on exfoliation and stabilizing mechanism in various aqueous media. Different water-based exfoliation methods, such as liquid-phase exfoliation and electrochemical exfoliation, are surveyed. [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]

Effective extraction is an essential step in the sensitive and accurate analysis of sulfonamides (SAs) in complex samples. In this study, based on the chemical properties of SAs, a novel monolith-based adsorbent using 4-vinylbenzoic acid and 4-vinylphenylboronic acid as dual-functional monomers was tailored and employed as efficient extraction phase of solid-phase microextraction. Various characterized techniques were applied to investigate the structure and morphology of the obtained adsorbent. Due to the abundant functional groups, the synthetic adsorbent displayed satisfying extraction performance for target SAs through multiple interactions including ion-exchange, B–N coordination, π-π and hydrophobic interactions. Following elution with the desorption solution of methanol/formic acid (98.5/1.5, v/v), the extractive SAs were measured by HPLC-MS/MS. Under the optimized conditions, the proposed approach exhibited wide linear ranges (0.005–10.0 μg/L for most of analytes), low limits of detection (in the range of 0.31–2.3 ng/L) and good precision (RSDs were lower than 8.0%). In the analysis of target SAs in environment waters and honey samples, the recoveries at low, medium and high spiked concentrations were in the range of 83.5–119%, and the RSDs (n = 3) varied from 0.6% to 9.6%. Compared with existing approaches, the current method presents some merits such as high sensitivity, good reproducibility, low consumptions of sample and organic solvent. Image 1 • A novel porous monolith-based adsorbent for MMF-SPME was prepared. • Multiply interactions contributed to the effective extraction of SAs. • Various parameters affecting the extraction performance were optimized. • Highly sensitive method for the quantification of trace SAs was developed. [ABSTRACT FROM AUTHOR]

Lignocellulosic material is an abundant renewable resource with the potential to replace petroleum as a feedstock for the production of fuels and chemicals. The large scale deployment of biomass saccharification is, however, hampered by the necessity to use aggressive reagents and conditions, formation of side-products, and the difficulty to reach elevated monosaccharide concentrations in the crude product. Herein we report the high efficacy of Reactive Aging (or Raging, a technique where enzymatic reaction mixtures, without any bulk aqueous or organic solvent, are treated to multiple cycles of milling and aging) for gram-scale saccharification of raw lignocellulosic biomass samples from different agricultural sources (corn stover, wheat straw, and sugarcane bagasse). The solvent-free enzymatic conversion of lignocellulosic biomass was found to proceed in excellent yields (ca. 90%) at protein loadings as low as 2% w/w, without the need for any prior chemical pre-treatment or high temperatures, to produce highly concentrated (molar) monosaccharides. This crude product of mechanoenzymatic depolymerization is non-toxic to bacteria and can be used as a carbon source for bacterial growth. [ABSTRACT FROM AUTHOR]

A facile method for fabricating polymer carbon dots (PCDs) with characteristic dual-emission at 570 and 620 nm by 1,8-naphthalenediol in n-propanol solvents was designed. The synthesised PCDs possessed fluorescence enhancement performance toward the water in organic solvents. Based on this peculiar phenomenon, a highly efficient fluorescent probe for water detection in organic solvents such as N,N-dimethylformamide, dimethyl sulfoxide and n-propanol was established with a wide detection range from 0 to 50%. The probe can also be utilised to determine water content in other organic solvents. The practical application was explored by studying the response of PCDs toward the water in various spirit samples. This method may offer a new way of detecting water in organic solvents by PCDs. [ABSTRACT FROM AUTHOR]

Two new families of lanthanide antennas are described. 8-Methoxy-4,5-dihydrocyclopenta[de]quinolin-2(1H)-one phosphonates or carboxylates behave as selective antennas exhibiting Eu3+ luminescence in organic solvents, while quinolin-2(1H)-one analogues selectively sensitize the Tb3+ emission. These emissions are quenched by H2O addition. Based on this behaviour, the new lanthanide antennas can be used as highly sensitive water sensors. [ABSTRACT FROM AUTHOR]

A highly crystalline covalent organic frameworks (COFs) formed by condensation reaction between 1, 3, 5-tris (4-aminophenyl) benzene and 4, 4′-biphenyldicarboxaldehyde is utilized as a sensing platform for water in organic solvent over a broad concentration range. The resulting COFs exhibits brilliant fluorescence in various organic solvents such as methanol, DMF, acetonitrile and ethanol, moreover its fluorescence intensity has a significant and rapid response to the content of water in organic solvent over a broad concentration range. The broadest sensing range is achieved over 7%–70% (v/v) for water in DMF, and the lowest limit of detection is 0.042% (v/v) for water in methanol among the investigated organic solvents. The superior properties of the sensing platform expand the application ranges of COFs and endow the resulting COFs with a great prospect in practical applications for highly efficient detecting water in organic solvent. A fluorescence sensor for detecting water in organic solvent has been constructed based on an emerging material (COFs) over a broad range from 7% to 70% (v/v) for water in DMF. The sensing platform proposes a potential approach for monitoring water in organic solvent. Image 1 • The highly crystalline COFs has been synthesized successfully. • The COFs could serve as a sensing platform for water in organic solvent. • A broad concentration range and high sensitivity revealed the advantages of the platform. • The platform showed potential application in monitoring contaminant in environment and chemical industry. [ABSTRACT FROM AUTHOR]

Two new hydroxyl-containing polyimides (PIs) with excellent comprehensive performances were designed and synthesized. After PIs react with fluoride ion (F−), the resulting polyimide-fluoride complexes (PI-1 ·F and PI-2 ·F) are exploited as ratiometric and colorimetric sensors for detecting trace water in DMSO/DMF with high sensitivity. Both sensors PI-1 ·F and PI-2 ·F exhibit a good naked-eye visual detection as well as an excellent linear relationship between the UV– vis absorbance ratio and the low water content in DMSO/DMF, which constitutes a quantitative method for determining water content in DMSO/DMF. The limits of detection (LOD) of sensor PI-1 ·F for water in DMSO and DMF are as low as 0.0035% and 0.0031% (v/v), respectively. The sensor PI-2 ·F shows the higher sensitivity for water detection with extremely low detection limits of 0.00084% and 0.0015% in DMSO and DMF, respectively. Furthermore, PI films have been directly used for the visual sensing of water in acetonitrile, acetone and ethanol, which provides an effective way for fabricating high-performance film-based water sensor devices. Image 1 • Two hydroxyl-containing polyimides are successfully synthesized. • Polyimide-fluoride complexes are applied for detecting trace water in organic solvents. • The sensors show high sensitivity toward a trace amount of water in DMSO and DMF. • The sensors exhibit a good naked-eye visual water detection. • PI films are directly used for visual detection of water in organic solvents. [ABSTRACT FROM AUTHOR]

Multiple‐stimuli‐responsive photoluminescence films based on a ZnII–organic framework, {[Zn2(Htpim)(3,4‐pydc)2]⋅4 DMF⋅4 H2O}n (1, Htpim=2,4,5‐tri(4‐pyridyl)imidazole, 3,4‐H2pydc=3,4‐pyridinedicarboxylic acid), were fabricated. This compound consisted of a 2D corrugated layer, {Zn(3,4‐pydc)}n, which was further pillared using a Y‐shaped pillar N‐donor ligand (Htpim) to form a 3D‐pillared‐layer framework with 1D open channels. The rectangular channels in the as‐synthesized compound are fully occupied by guest DMF and H2O molecules. The framework exhibits instant and reversible thermochromic properties corresponding to the removal of different H2O and DMF guest molecules as temperature increases. The pale‐yellow crystal undergoes significant redshifting to a greenish emission centered at 530 nm. Compound 1 also showed remarkable solvatochromic effects in the presence of various organic solvents without affecting its structural integrity. In addition, polycrystalline MOF films were grown on an α‐Al2O3 support for switchable and fast‐response thermochromic and solvatochromic sensors. [ABSTRACT FROM AUTHOR]

In the present investigation, a green aqua‐mediated protocol for the synthesis of novel 2‐arylidene indanone derivatives from 1,2,6,7‐tetrahydro‐8H‐indeno[5,4‐b]furan‐8‐one was unveiled. The application of water in organic reactions as a solvent is one of the incredible tools of green chemistry as reactions can be carried out under benign conditions minimizing environmental hazard and chemical waste. A library of novel 2‐arylidene indanone derivatives are synthesized in good to excellent yield by utilizing the green potential of water as a solvent. The structures of all novel 2‐arylidene indanone derivatives reported herein are confirmed using Fourier‐transform infrared spectroscopy (FTIR), 1H NMR, 13C NMR, 19F NMR, distortionless enhancement by polarization transfer (DEPT), and High Resolution Mass Spectrometry (HRMS) techniques. [ABSTRACT FROM AUTHOR]

A novel liquid-based Janus porous membrane system was developed through the simple infusion of water and oil within different surfaces. This generates a stable liquid-infusion interface that repels immiscible organic solvents and water, and itself floats at the oil/water interface as a separator. The developed membrane successfully acts as a simple alternative for high-performance liquid separation. [ABSTRACT FROM AUTHOR]

The current industrial approach to sonidegib utilizes wasteful organic solvents and relies on high loadings of endangered Pd. This anticancer drug can now be synthesized in 5 steps using only 3 pots, along with ppm levels of a Pd catalyst, all done in water at ambient temperatures. [ABSTRACT FROM AUTHOR]