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Electronic (e-) cigarette formulations containing nicotine salts from a range of organic acid conjugates and pH values have dominated the commercial market. The acids in the nicotine salt formulations may alter the redox environment in e-cigarettes, impacting free radical formation in e-cigarette aerosol. Here, the generation of aerosol mass and free radicals from a fourth-generation e-cigarette device was evaluated at 2 wt % nicotine salts (pH 7, 30:70 mixture propylene glycol to vegetable glycerin) across eight organic acids used in e-liquids: benzoic acid (BA), salicylic acid (SLA), lactic acid (LA), levulinic acid (LVA), succinic acid (SA), malic acid (MA), tartaric acid (TA), and citric acid (CA). Furthermore, 2 wt % BA nicotine salts were studied at the following nicotine to acid ratios: 1:2 (pH 4), 1:1 (pH 7), and 2:1 (pH 8), in comparison with freebase nicotine (pH 10). Radical yields were quantified by spin-trapping and electron paramagnetic resonance (EPR) spectroscopy. The EPR spectra of free radicals in the nicotine salt aerosol matched those generated from the Fenton reaction, which are primarily hydroxyl (OH) radicals and other reactive oxygen species (ROS). Although the aerosol mass formation was not significantly different for most of the tested nicotine salts and acid concentrations, notable ROS yields were observed only from BA, CA, and TA under the study conditions. The e-liquids with SLA, LA, LVA, SA, and MA produced less ROS than the 2 wt % freebase nicotine e-liquid, suggesting that organic acids may play dual roles in the production and scavenging of ROS. For BA nicotine salts, it was found that the ROS yield increased with a higher acid concentration (or a lower nicotine to acid ratio). The observation that BA nicotine salts produce the highest ROS yield in aerosol generated from a fourth-generation vape device, which increases with acid concentration, has important implications for ROS-mediated health outcomes that may be relevant to consumers, manufacturers, and regulatory agencies.

The Hofmeister series characterizes the ability of salt anions to precipitate polyampholytes/proteins. However, the variation of protein size in the bulk solution of acids and the effect of salts on the same have not been studied well. In this article, the four acids (CH3COOH, HNO3, H2SO4, and HCl) and their effects on the hydrodynamic radius (RH) of gelatin in the bulk solution are investigated. The effects of Na salt with the same anions are also considered to draw a comparison between the interactions of acids and salts with polyampholytes. It is suggested that the interactions of polyampholytes with acids are different from those of salts. The interaction series of polyampholytes with acids with respect to the RH of the polyampholyte is C H 3 CO O − > N O 3 − > C l − > S O 4 2 − whereas the interaction series with salts is S O 4 2 − > C H 3 CO O − > C l − > N O 3 − . These different interactions are due to equilibration between acid dissociation and protonation of polyampholytes. Another important factor contributing to the interactions in weak acids is the fact that undissociated acid hinders the movement of dissociated acid. Experiments and simulations were performed to understand these interactions, and the results were identical in terms of the trend in RH (from the experiments) and the radius of gyration (Rg) (from the simulations). It is concluded that the valence of ions and dissociation affect the interaction in the case of acids. However, the interactions are influenced by the kosmotropic and chaotropic effect, hydration, and mobility in the case of salts. [ABSTRACT FROM AUTHOR]

The species Ph3PNNC 1 reacts with the group 13 Lewis acids E(C6F5)3 (E = B or Al), HB(C6F5)2, ClAl(C6F5)2 and ECl3 (E = Ga or In) to give the Lewis acid–base adduct Ph3PNNCB(C6F5)3 2, the zwitterionic product (Ph3PNH)B(C6F5)2CNB(C6F5)2H 3, the chelated salts [(Ph3PNNC(CN)NPPh3)ER2][EX2R2] (E = Al, R = X = C6F5, 4; E = Al, R = C6F5, X = Cl, 5; E = Ga, R = X = Cl, 6), and the neutral species [(Ph3PNNC(CN)NPPh3)InCl3] 7. The nature of these variations in reactivity are rationalized and the potential utility considered. [ABSTRACT FROM AUTHOR]

The development of novel synthetic methods for quaternary ammonium salts is highly demanded since the current synthesis heavily relies on the conventional Menshutkin reaction. Herein, we report photoredox-catalyzed alkylation of α-brominated alkenylammonium salts. Mechanistically, the generation of a highly reactive α-ammoniovinyl radical is the key to our method. This reaction enables the synthesis of various unprecedented α-alkylated alkenylammonium salts. [ABSTRACT FROM AUTHOR]

2,4,6‐Triaminopyrimidine is an interesting and challenging molecule due to the presence of multiple hydrogen‐bond donors and acceptors. Its noncovalent interactions with a variety of carboxylic acids provide several supramolecular aggregates with frequently occurring molecular synthons. The present work focuses on the supramolecular interactions of 2,4,6‐triaminopyrimidinium 3‐(indol‐3‐yl)propionate–3‐(indol‐3‐yl)propionic acid (1/1), C4H8N5+·C11H10NO2−·C11H11NO2, (I), 2,4,6‐triaminopyrimidinium 2‐(indol‐3‐yl)acetate, C4H8N5+·C10H8NO2−, (II), 2,4,6‐triaminopyrimidinium 5‐bromothiophene‐2‐carboxylate, C4H8N5+·C5H2BrO2S−, (III), and 2,4,6‐triaminopyrimidinium 5‐chlorothiophene‐2‐carboxylate, C4H8N5+·C5H2ClO2S−, (IV). All four salts exhibit robust homomeric and heteromeric R22(8) ring motifs. Salts (I) and (II) develop sextuple [in (I)] and quadruple [in (I) and (II)] hydrogen‐bonded arrays through fused‐ring motifs. Salt (II) exhibits a rosette‐like architecture. Salt (IV) is isostructural and isomorphous with salt (III), exhibiting an identical crystal structure with a different composition and an identical supramolecular architecture. In salts (III) and (IV), a linear hetero‐tetrameric motif is formed and, in addition, both salts exhibit halogen–π interactions which enhance the crystal stability. All four salts develop a supramolecular hydrogen‐bonded pattern facilitated by several N—H...O and N—H...N hydrogen bonds with multiple furcated donors and acceptors. [ABSTRACT FROM AUTHOR]

A significant and sustainable feedstock for many value added products is levulinic acid, which is basically a short‐chain fatty acid. The current study aims to comprehend how multiple factors affect the hydrothermal reactions that convert glucose to levulinic acid. Glucose can be readily obtained from lignocellulosic biomass and hence it is selected in the work as representative sustainable source. The effect of various operating parameters, including time (0–180 min), temperature (140–180°C), nitrogen pressure (0–25 bar), glucose concentration (3%–10%), agitation speed (100–300 RPM), and acid concentration (2%–6%); use of different salts (NaCl, AlCl3 6H2O, FeCl3); and different acids (HCl, H3PO4, H2SO4) on the reaction progress has been studied in a batch autoclave reactor. It was elucidated that pressure (only nitrogen purge was essential for reaction progress) or salt content changes did not affect sugar conversion significantly. The process was seriously influenced by the presence of acids, mostly in the form of homogeneous catalysts, and the most significant results were obtained for H2SO4. The highest levulinic acid yield (39.7 g/g) at 90 min, with nearly complete sugar conversion, was obtained under the ideal conditions of 160°C, 5% sugar loading, and 5% H2SO4 concentration. The current study indicates that the two primary operating parameters in this conversion process are temperature and time, with higher temperature and lower sugar concentration showing a rising tendency in sugar conversion. Overall, the study establishes a sustainable process for levulinic acid synthesis. [ABSTRACT FROM AUTHOR]

111In and 109Cd radionuclides were produced by 31 MeV α ${\alpha }$ ‐particle irradiation of natAg target. To separate no‐carrier added (NCA) 111In and 109Cd from bulk Ag, Aqueous Biphasic System (ABS) was constructed using twelve salts and two polyethylene glycol (PEG) combinations. Out of all these combinations, only three salts e. g., Na2SO3, Na‐ malonate and Na‐Tartrate and PEG combinations showed significant separation between bulk Ag and NCA radioisotopes. Addition of catechins extracted from green tea to the above ABS systems increased the separation factors many folds. Highest separation factor (SIn/Ag=5.6×104) for 111In was obtained in Na2SO3‐PEG 4000 and 50 mg catechins system. 109Cd retained in NCA state in the Na‐malonate phase after the extraction of 111In and bulk Ag in the catechin‐PEG phase. [ABSTRACT FROM AUTHOR]

In this study, we introduce a salt-responsive hydrogel system utilizing a sugar-derived surfactant featuring a polyhydroxy spacer in its headgroup. The inclusion of salts enhances and organizes the intermolecular hydrogen bonding within the hydrophilic region of the polyhydroxy spacer, promoting cross-linking among surfactant molecules. [ABSTRACT FROM AUTHOR]

Herein, we have described a novel organocatalytic approach to access biologically important dihydropyridin-2-ones in a one-pot way with generally high yields (up to 99%) and excellent enantioselectivities (up to 99% ee). This reaction proceeded via a new dual activation mode, including in situ-generated α,β-unsaturated acylazoliums and 4-dimethylaminopyridinium salts that underwent a Michael addition/1,4-H migration/lactamization sequence. The base-triggered 4-dimethylaminopyridinium ylide formation pathway over the competing substitution reaction pathway of vicinal haloamines is noteworthy. [ABSTRACT FROM AUTHOR]

ABSTRACT The design and synthesis of insensitive energetic materials are a necessary and challenging work. The synthesis of novel nitrogen‐rich salts based on 5‐(5‐Nitro‐1H‐1,2,4‐triazol‐3‐yl)‐1H‐tetrazole (H2NTT) has been presented. Structural characterization of these two salts was accomplished by utilizing NMR, MS, IR spectroscopy, and X‐ray diffraction. The standard heats of formation were calculated, and the differential scanning calorimetry (DSC) and sensitivity test were carried out. Their detonation performances were estimated by EXPLO 5 program. These newly synthesized salts showed highly positive heat of formation and low sensitivity. It is noteworthy that the diaminoguanidine salt b exhibited good detonation performance superior to traditional explosive TNT (Trinitrotoluene), making it a prospective candidate for insensitive energetic material. [ABSTRACT FROM AUTHOR]

A thermally stable and high nitrogen content energetic cation N,N'‐methylene‐bis(3,4,5‐triamino‐1,2,4‐triazolium) (MTAT, N = 69.38%, ΔHf = 1959.07 kJ/mol) has been used as a building block for preparing a new family of energetic salts. Compounds 1 and 4 were characterized by infrared and multinuclear NMR spectra. Structural confirmation of four salts (1–4) was supported by single‐crystal X‐ray diffraction. Theoretical calculations were performed to calculate the heats of formation and detonation performance using Gaussian 09 and EXPLO5 v6.05 programs, respectively. The impact and friction sensitivity of COMPOUNDS 1 and 2 were measured using BAM standards. Based on experimental and theoretical results, two energetic salts (1 and 3) featuring the novel cation framework MTAT exhibited favorable densities ranging from 1.751 to 1.809 g cm−3 at 298 K, excellent thermal stability (Td: 250–257 °C), acceptable detonation performance (D: 8001–8097 m s−1, P: 23.3–26.7 GPa), and good impact and friction sensitivity (IS: 18–40 J, FS: 240–360 N). [ABSTRACT FROM AUTHOR]

A new class of anion–π+ AIEgens based on ring-fused annulated oxazolium architectures is reported, which can be readily synthesized via a single-step dual C–H activation annulative π-extension (APEX) protocol from simple oxazolium salts. The crucial and decisive role of anion–π+ interactions in their solid-state structural arrangement was analyzed to correlate their tunable AIE features and solid-state quantum yields. [ABSTRACT FROM AUTHOR]

Herein, we report a diastereoselective dearomative bifunctionalization strategy of using isoquinolinium salts to access bridged tetrahydroisoquinolines. The strategy relies on the strategic use of allenes and amines as reaction partners to generate binucleophilic species in situ for subsequent dearomatization. [ABSTRACT FROM AUTHOR]

A novel and efficient method has been developed for synthesizing benzothioamide from benzonitrile in supercritical CO2, which could be used to synthesize various benzothioamide derivatives efficiently with yields of up to 98% without the need for organic solvent. Notably, some H2S-based salts were designed and prepared, and they were found to be effective catalysts in promoting the thiolysis of benzonitrile to produce benzothioamide in an excellent yield. Furthermore, the utilization of supercritical CO2 as a solvent has demonstrated a remarkable increase in the yield of the desired product compared to conventional solvents for promoting benzonitrile thiolysis. Additionally, the investigation of the reaction mechanism has revealed that the acid–base properties of the reaction solution played a crucial role in the thiolysis of benzonitrile mediated by the H2S-based salts. [ABSTRACT FROM AUTHOR]

A novel and efficient method has been developed for synthesizing benzothioamide from benzonitrile in supercritical CO2, which could be used to synthesize various benzothioamide derivatives efficiently with yields of up to 98% without the need for organic solvent. Notably, some H2S-based salts were designed and prepared, and they were found to be effective catalysts in promoting the thiolysis of benzonitrile to produce benzothioamide in an excellent yield. Furthermore, the utilization of supercritical CO2 as a solvent has demonstrated a remarkable increase in the yield of the desired product compared to conventional solvents for promoting benzonitrile thiolysis. Additionally, the investigation of the reaction mechanism has revealed that the acid–base properties of the reaction solution played a crucial role in the thiolysis of benzonitrile mediated by the H2S-based salts. [ABSTRACT FROM AUTHOR]

We describe the transition-metal-free coupling for polyfluoroalkoxy arenes using polyfluoroalkoxy borates, which serve as counterions to diaryliodonium salts and transferring mediators of polyfluoroalkoxy groups. This strategy demonstrates high functional group compatibility owing to the low nucleophilicity of the borate mediator, thus offering a practical approach for synthesizing diverse polyfluoroalkoxy arenes. [ABSTRACT FROM AUTHOR]

This work reports the synthesis and structural study of a family of chlorotriarylbismuthonium salts. The abstraction of a chlorine atom with NaBArF from triarylbismuth dichloride species leads to monomeric and dimeric chlorotriarylbismuthonium species, which show a distinct behavior in solution and solid-state in comparison to their fluorotriarylbismuthonium analogues. [ABSTRACT FROM AUTHOR]

The 2,7‐fluorenone‐linked bis(6‐imidazo[1,5‐a]pyridinium) salt H2‐1(PF6)2 reacts with Ag2O in CH3CN to yield the [2]catenane [Ag4(1)4](PF6)4. The [2]catenane rearranges in DMF to yield two metallamacrocycles [Ag2(1)2](PF6)2. 2,7‐Fluorenone‐bridged bis‐(imidazolium) salts H2‐L(PF6)2 (L=2 a, 2 b) react with Ag2O in CH3CN to yield metallamacrocycles [Ag2(L)2](PF6)2 with interplanar distances between the fluorenone rings too small for [2]catenane formation. Intra‐ and intermolecular π⋅⋅⋅π interactions between the fluorenone groups were observed by X‐ray crystallography. The strongly kinked 2,7‐fluorenone bridged bis(5‐imidazo[1,5‐a]pyridinium) salt H2‐4(PF6)2 reacts with Ag2O to yield [Ag2(4)(CN)](PF6), while the tetranuclear assembly [Ag4(4)2(CO3)](PF6)2 was obtained in the presence of K2CO3. [ABSTRACT FROM AUTHOR]

A direct visible‐light‐promoted radical‐triggered tandem cyclization of 1,7‐diene systems with cyclic sulfonium salts by using copper(I)‐based complexes as photoredox catalyst is developed. With this approach, a variety of sulfur‐containing polycyclic derivatives are prepared through alkylation/6‐exo‐trig cyclization/5‐exo‐trig cyclization of 1,7‐diene systems under mild conditions. In addition, the photoinduced copper‐catalyzed ring‐opening of cyclic sulfonium salts provides the alkyl radical intermediates, which prefers addition to the C−C double bond that connected to the aromatic ring rather than the electron‐deficient vinyl in 1,7‐dienes. Moreover, oxidation of the desired sulfur‐containing polycyclic products provides a strategy for the preparation of remote nitrogen‐fused polycyclic substituted sulfoxide or sulfone‐containing derivatives. [ABSTRACT FROM AUTHOR]

Solid-state [2+2] photodimerization of eniminium ions oriented in a head-to-tail manner controlled by cation–π interactions produced synHT dimers in high yields. As the resulting dimer is readily converted to 1,3-diacetylcyclobutane, the iminium serves as a removable orientation-controlling group for the conjugated ketones. [ABSTRACT FROM AUTHOR]

We report the implementation of a consecutive photoinduced electron transfer (conPET) strategy for the functionalization of white phosphorus (P4) with inexpensive and widely available aryl bromides and chlorides. By employing a well-known acridinium-based photocatalyst under near-UV irradiation, this protocol gives direct access to valuable triarylphosphines and tetraarylphosphonium salts. The reaction mechanism is elucidated by NMR spectroscopic studies and model reactions. [ABSTRACT FROM AUTHOR]

Herein, an operationally simple and mild protocol for defluorinative alkylation and arylation between thianthrenium salts and α-trifluoromethyl alkene with visible light to afford gem-difluoroolefins has been developed. The main feature of this method is avoiding the use of a metal photocatalyst, and an organic photocatalyst is unnecessary for the arylation reaction. In addition, thianthrene can also be recycled and transformed to thianthrenium salts without affecting the efficiency of these reactions. The protocol demonstrates excellent tolerance of functional groups and viable functionalization of late-stage natural products and pharmaceutically relevant molecules. [ABSTRACT FROM AUTHOR]

Formal olefinic C−P cross‐coupling between alkenyl sulfonium salts and secondary phosphine oxides and H‐phosphinates has been developed. A base enables construction of alkenyl C−P bonds as well as aliphatic C−P bonds at ambient temperature under an air atmosphere. This protocol provides an alternative access to multisubstituted alkenyl phosphine oxides and phosphinates in 40–99% yield from functionalized alkenes through an interrupted Pummerer activation/base‐promoted olefinic C−S bond phosphinylation sequence. Gram‐scale preparation and feasible derivatization demonstrated the applicability of the resultant alkenylphosphine oxides. [ABSTRACT FROM AUTHOR]

Isotopically labeled alkanes play a crucial role in organic and pharmaceutical chemistry. While some deuterated methylating agents are readily available, the limited accessibility of other deuteroalkyl reagents has hindered the synthesis of corresponding products. In this study, we introduce a nickel‐catalyzed system that facilitates the synthesis of various deuterium‐labeled alkanes through the hydrodeuteroalkylation of d2‐labeled alkyl TT salts with unactivated alkenes. Diverging from traditional deuterated alkyl reagents, alkyl thianthrenium (TT) salts can effectively and selectively introduce deuterium at α position of alkyl chains using D2O as the deuterium source via a single‐step pH‐dependent hydrogen isotope exchange (HIE). Our method allows for high deuterium incorporation, and offers precise control over the site of deuterium insertion within an alkyl chain. This technique proves to be invaluable for the synthesis of various deuterium‐labeled compounds, especially those of pharmaceutical relevance. [ABSTRACT FROM AUTHOR]

Pyrylium salts based on a cationic oxygen heterocycle are a key class of chromophores. However, synthesis of these salts generally requires use of harsh acids, copious organic solvents, and in many cases, hazardous conditions. This work provides a two-pot synthesis for substituted triphenyl pyrylium salts wherein chalcone intermediates are first prepared and then mild methanesulfonic acid is used in combination with a dehydrating agent to drive pyrylium cyclization. Purification is achieved through a simple, aqueous workup involving counterion metathesis which avoids the need for environmentally unfriendly organic solvents. This mild, green approach has been applied to synthesize a collection of known pyryliums as well as a new family of red-shifted pyrylium chromophores bearing p -pyrrolidinylphenyl substituents. The synthesis of the latter group demonstrates that unlike other current methods, our approach offers enhanced functional group tolerance as well as finer control over substituent placement. [ABSTRACT FROM AUTHOR]

A simple and efficient synthesis of cis- and trans-myrtanic acids in preparative yields of 54–58% and 72–74%, respectively, was proposed and consisted of oxidation of cis- and trans-myrtanols by CrO3–AcOH upon addition of the oxidant to a solution of the starting alcohols at room temperature. Tests of the obtained compounds for antifungal activity showed lower activity for the quaternary salts than for the starting acids and greater efficacy for the cis-isomers than for the trans-isomers. However, the alcohols themselves, i.e., cis- and trans-myrtanols and (–)-myrtenol, had the greatest activities. [ABSTRACT FROM AUTHOR]

Environmental pollution significantly challenges human health, ecosystems, and the planet's sustainability. Widespread air, water, and soil contamination from various pollutants requires effective and sustainable solutions to reduce or eliminate pollution and its impacts. In this work, we designed novel magnesium oxide and graphene oxide (MgO@GO) composite free-standing membranes for nanofiltration. The membranes were characterized with the help of Fourier-transform infrared spectroscopy, X-ray diffraction, field-emission scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Further, free-standing MgO@GO composite membranes with different thicknesses were used to measure the water permeance. 410 nm-thick membranes showed high water permeance up to 480 ± 5 Lm−2 h−1 bar−1. Further, the rejection efficiency of the membrane was measured against NaCl, CaCl2, Pb(NO3)2, CdCl2, and amoxicillin. The MgO@GO membrane (410 ± 10 nm) showed 100% rejection for amoxicillin and 99% for Pb(NO3)2, respectively. Additionally, the membranes were stable under acidic and neutral conditions for approximately ∼80 days and may used on an industrial scale to ensure water is clean and free from harmful substances. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries (LSBs) are discussed as the most promising post‐lithium‐ion battery technology due to the high theoretical energy density and the cost‐efficient, environmental‐friendly active material sulfur. Unfortunately, LSBs still suffer from several limitations such as cycle life and rate capability. To overcome these issues, the development of adapted electrolytes is one promising path. Consequently, in this study, we focus on the influence of the lithium salt on the performance of LSBs. In a fixed solvent system without employing LiNO3, five different lithium salts are compared. The electrolyte properties as well as the influence of polysulfides are determined and discussed in relation with the battery performance. Interestingly, although the different salts lead to different electrolyte properties, only a minor influence of the salt is observed at low C‐rates. By performing a rate capability test, however, a strong influence of the lithium salt is detected at high C‐rates, with LiFSI outperforming the other salts. This correlates well with ionic conductivity and a suppressed influence of polysulfides in case of LiFSI. To verify the results, multi‐layered pouch cells were tested under lean electrolyte conditions. The study emphasizes the significance of the lithium salt and provides guidance for electrolyte design under lean electrolyte conditions. [ABSTRACT FROM AUTHOR]

The Stebnytsy salt deposit is located in the internal Boryslav-Pokut subzone of Precarpathia (Ukraine). Mine No. 2 was operated for more than 20 years. During this period, about 15 million m3 of man-made voids were formed and not laid. Due to water inflows that are aggressive in relation to the host rocks, mine No. 2 of the Stebnytskyi potash deposit is recognized as emergency. Taking into account the irreversible nature of this process and the threat to the environment, a decision was made about its wet preservation. Mine No. 2 of the Stebnytsky salt deposit is in the post-exploitation stage, its wet conservation is being implemented. Targeted wet conservation of a salt mine is being carried out for the first time in the world. Due to the lack of adequate funding, the implementation of the conservation project took place significantly behind the grid schedule, this led to the technical impossibility and impracticality of carrying out certain works provided for by the project, as a result of which negative ecological processes are taking place, which pose a threat to the environment. To date, suffusion-diffusion processes have gone beyond the limits of the mine removal of the deposit and the deformation of the earth's surface threatens critical infrastructure facilities and residential buildings. An evaluation of the exogeodynamic situation, which was formed as a result of natural and man-made factors in the process of wet conservation of mine No. 2, was carried out. An analysis of the results of revision interval testing of brines in the mine was carried out, it was investigated that in the areas of direct contact of salt-bearing strata with aggressive brines, the latter acquire an equilibrium concentration in a short period of time. It was established that in the specified zone of water supply, which entered the mined workings, there are flooded karst cavities that can be deformed by external factors, for example, by dynamic loads from traffic. The article highlights the results of instrumental monitoring, on the basis of which an assessment of hydrogeological conditions and an analysis of the dynamics of flooding of mine No. 2 was performed, and an assessment of the state of the man-made geological system "man-made complex-geological environment" at the post-operational stage of mine No. 2 was carried out. [ABSTRACT FROM AUTHOR]

Hypersaline brines provide excellent opportunities to study extreme microbial life. Here, we investigated anabolic activity in nearly 6000 individual cells from solar saltern sites with water activities (aw) ranging from 0.982 to 0.409 (seawater to extreme brine). Average anabolic activity decreased exponentially with aw, with nuanced trends evident at the single-cell level: The proportion of active cells remained high (>50%) even after NaCl saturation, and subsets of cells spiked in activity as aw decreased. Intracommunity heterogeneity in activity increased as seawater transitioned to brine, suggesting increased phenotypic heterogeneity with increased physiological stress. No microbial activity was detected in the 0.409-aw brine (an MgCl2-dominated site) despite the presence of cell-like structures. Extrapolating our data, we predict an aw limit for detectable anabolic activity of 0.540, which is beyond the currently accepted limit of life based on cell division. This work demonstrates the utility of single-cell, metabolism-based techniques for detecting active life and expands the potential habitable space on Earth and beyond.

The Stebnytsy salt deposit is located in the internal Boryslav-Pokut subzone of Precarpathia (Ukraine). Mine No. 2 was operated for more than 20 years. During this period, about 15 million m3 of man-made voids were formed and not laid. Due to water inflows that are aggressive in relation to the host rocks, mine No. 2 of the Stebnytskyi potash deposit is recognized as emergency. Taking into account the irreversible nature of this process and the threat to the environment, a decision was made about its wet preservation. Mine No. 2 of the Stebnytsky salt deposit is in the post-exploitation stage, its wet conservation is being implemented. Targeted wet conservation of a salt mine is being carried out for the first time in the world. Due to the lack of adequate funding, the implementation of the conservation project took place significantly behind the grid schedule, this led to the technical impossibility and impracticality of carrying out certain works provided for by the project, as a result of which negative ecological processes are taking place, which pose a threat to the environment. To date, suffusion-diffusion processes have gone beyond the limits of the mine removal of the deposit and the deformation of the earth’s surface threatens critical infrastructure facilities and residential buildings. An evaluation of the exogeodynamic situation, which was formed as a result of natural and man-made factors in the process of wet conservation of mine No. 2, was carried out. An analysis of the results of revision interval testing of brines in the mine was carried out, it was investigated that in the areas of direct contact of salt-bearing strata with aggressive brines, the latter acquire an equilibrium concentration in a short period of time. It was established that in the specified zone of water supply, which entered the mined workings, there are flooded karst cavities that can be deformed by external factors, for example, by dynamic loads from traffic. The article highlights the results of instrumental monitoring, on the basis of which an assessment of hydrogeological conditions and an analysis of the dynamics of flooding of mine No. 2 was performed, and an assessment of the state of the man-made geological system “man-made complex-geological environment” at the post-operational stage of mine No. 2 was carried out.

The Stebnytsy deposit of potash salts is located in the inner Boryslav-Pokut subzone of the Precarpathian depression, Ukrainian Carpathians. The hydrogeological conditions of the Stebnytsky deposit are difficult, therefore mining operations are not carried out at the deposit, and only environmental protection measures are carried out. The mines are under conservation. During the period of operation of the deposit, about 30 million m3 of unfilled man-made voids were formed. To date, the suffusion and diffusion processes of the Stebnytskyi salt deposit have gone beyond the limits of the mine drainage of the deposit, and the deformation of the earth's surface threatens critical infrastructure facilities and residential buildings. As a result of the systematic regular observations of brine manifestations in the Stebnytsky deposit and studies of the processes of interaction of brines with the host rock, an idea was obtained about the peculiarities and regularities of the formation of the modern hydrochemical situation in the deposit, which in turn will allow to assess the degree of danger of individual areas in relation to the penetration of aggressive waters into underground workings salt mine. This article presents ideas about the nature of brines, the samples of which were taken from the revealed brine manifestations in the mine workings of the deposit. These ideas boil down to the fact that the vast majority of studied brines are brines of sedimentary origin and only a small part of them to one degree or another formed their composition due to salt leaching processes. Some regularities of changes in the chemical composition of solutions of sedimentary origin, which are formed in the conditions of deposits of sulfated potassium-magnesium salts, are considered. Research was conducted to study the interaction of brines with kainite rock, the results of the research allow us to establish the parameters characteristic of these solutions, and at the same time, to find out the secondary mineral formation that accompanies this process.

A copper‐catalyzed C4‐selective addition of silicon nucleophiles released from an Si−B reagent to prochiral pyridinium triflates is reported. The dearomatization proceeds with excellent enantioselectivity using Cu(CH3CN)4PF6 as the precatalyst and (R,R)‐Ph‐BPE (1,2‐bis[(2R,5R)‐2,5‐diphenylphospholan‐1‐yl]ethane) as the chiral ligand. A carbonyl group at C3 is required for this, likely acting a weak donor group to preorganize and direct the nucleophilic attack towards C4. The resulting 4‐silylated 1,4‐dihydropyridines can be further converted into functionalized piperidine derivatives. [ABSTRACT FROM AUTHOR]

The Kröhnke Pyridine Synthesis has been discovered about six decades ago (1961), by Fritz Kröhnke and Wilfried Zecher at the University of Giessen. The original method involved the reaction of α‐pyridinium methyl ketone salts with α,β‐unsaturated carbonyl compounds in the presence of a nitrogen source, frequently ammonium acetate. Since its discovery, the Kröhnke methodology has been demonstrated to be suitable for the preparation of mono‐, di‐, tri‐ and tetra‐pyridines, with important applications in several research fields. Over the years, a number of modifications to the original approach have been developed and reported, enabling for the broad applicability of these methods even in modern days, also for the synthesis of non‐pyridine compounds. In this critical and tutorial review, we will thoroughly explore and discuss the potential of the original method, the refinements that have been made over the years, as well as some applications arising from each type of pyridine and/or non‐pyridine compounds produced by Kröhnke's approach. [ABSTRACT FROM AUTHOR]

The interactions of salts with polyampholytes are well established using the Hofmeister series. However, the effect of these salts on the diffusivities of polyampholytes is unknown. This article discusses these electrostatically driven physical interactions using two developed prediction models. Sodium and Potassium salts are considered with 3 chaotropic anions and 2 kosmotropic anions. A dimensionless parameter has been developed to predict the trend for these salt interactions. Another model has been developed to predict these interactions for different salt mixtures. The effect of these salts and the mixtures on the second virial coefficient is also studied, and statistical clustering using the k‐means method has been defined, which can provide insight towards the changes in the solution properties of polyampholytes with these salt mixtures. At lower pH, the salt first screens the repulsions in the polyampholytes followed by a re‐expansion phenomenon. [ABSTRACT FROM AUTHOR]

The tetracyanoborate anion [B(CN)4]− (TCB) was utilized as a building block for the synthesis of polynuclear chromium carbonyl compounds upon photolytic reaction with [Cr(CO)6]. Up to four κN-coordinated cyano groups of TCB can be involved in binding to chromium, giving mixtures of [B(CN)4−x{CN–Cr(CO)5}x]− (x = 1–4; 1–4) and [{Cr(CO)4(B(CN)4)}2]2− (5). The reaction of [B(CN)4]− with fac-[Cr(CO)3(MeCN)3] led to isolation of salts of the tetraanionic heterocubane cage [{Cr(CO)3(B(CN)4)}4]4−. [ABSTRACT FROM AUTHOR]

The tetracyanoborate anion [B(CN)4]− (TCB) was utilized as a building block for the synthesis of polynuclear chromium carbonyl compounds upon photolytic reaction with [Cr(CO)6]. Up to four κN-coordinated cyano groups of TCB can be involved in binding to chromium, giving mixtures of [B(CN)4−x{CN–Cr(CO)5}x]− (x = 1–4; 1–4) and [{Cr(CO)4(B(CN)4)}2]2− (5). The reaction of [B(CN)4]− with fac-[Cr(CO)3(MeCN)3] led to isolation of salts of the tetraanionic heterocubane cage [{Cr(CO)3(B(CN)4)}4]4−. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Although various routes have been reported for haloazidation, unavoidable problems exist, such as environmentally unfriendly monomer halogen, the need for in situ generation of unstable halogen azides (XN3), applicability to one type of haloazidation and inability to precisely control selectivity. Herein, we developed a universal strategy for haloazidation of alkenes through controlling the reactivity of IBA‐N3 by switching halogen salts, allowing for the synthesis of a diversity of halogen azide products. Mechanistic studies have shown that by tuning the reactivity of IBA‐N3 via switching halogen salts, different intermediates can be controllably produced to achieve regioselectivity and chemoselectivity in the haloazidation of alkenes. [ABSTRACT FROM AUTHOR]

Examination of effect of five inorganic chlorine salts (NaCL, KCL, CaCL2, CuCL2.2H2O and FeCL3.6H2O) on wheat seeds from three different wheat cultivars (“Enola C1”, “Tcarevetz” and “Aleksa”), was conducted in the in vitro conditions. Chloride (Cl) is one of the 17 essential nutrients required for plant growth and development. Chloride plays a major role in plant function, including photosynthesis, enzyme activation, nutrient transport, water movement in cells, stomata activity, accelerated plant development, reduced lodging, and improved disease suppression and tolerance. However some studies reveal the toxic action of chloride salts towards different terrestrial and aquatic plants. The purpose of present study was to investigate if NaCL, KCL, CaCL2, CuCL2.2H2O and FeCL3.6H2O have toxic action on germination of wheat seeds. The wheat seeds were placed in the double layer of Whatman filter paper. The papers with seeds were placed in closed plastic bags and 40 ml of the tested solution was poured on the bottom of the bags. The bags were placed in the thermostat at 22 °C for two weeks. Each bag was equal to the one test repetition; each test variant consists of five test repetitions. At the end of the test, percent germination, the length of shoots and roots were measured. Also, the visual observations for phytotoxicity (necrosis, chlorosis and deformations) onto shoots and roots were performed. ANOVA analysis was performed in order to be reveled statistically proved differences between tested variants via R language for statistical computing. The study confirm the toxic action of tested inorganic salts towards wheat and slightly stimulation effect of sodium and potassium chloride at low concentrations on wheat’s growth. Trials conform the strong phytotoxic action of ferric and especially copper chlorides on wheat seeds and plants. The conducted tests show all tested inorganic chlorine salts can strongly inhibit the germination rates of wheat seeds and growth of shoots and roots. However, some of them as sodium and potassium chloride at very low concentrations-0.01-0.05 % (m/v) can express slight stimulation effect on seeds. Ferric and copper chlorides have strongest inhibition effect on wheat seeds in the conducted research. The fact that ferric chloride can act as ISR promoter in the plants and the results in the given study that the salt in very low concentration does not effects the growth and development of the plants is promising for future researchers in this direction. No differences between tested wheat cultivars were observed towards their response to the salts. [ABSTRACT FROM AUTHOR]

Aspects of the synthesis and isolation of (Bu4N)3[H3V10O28] (I) and Na6[V10O28]·18H2O (II) from one reaction mixture are considered. The procedure for the synthesis of compound I is optimized. The reaction of compound I and HSO3CF3 in dimethyl sulfoxide (DMSO) affords complex [VO2(DMSO)4](CF3-SO3) (III). A possibility of using complex III for the preparation of catalytically active materials based on polyethylene terephthalate (PET) is shown. [ABSTRACT FROM AUTHOR]

Water adsorption capacities of various adsorbents reported in the literature were investigated to define a hydrophobicity index that was plotted vs. water capacity. In this plot, logarithmic curves were proposed to be used as indicators of performance limits of adsorbents, especially for adsorption heat pumps. In spite of their useful adsorption properties, zeolites generally exhibited quite low hydrophobicity, remaining well below the logarithmic curve. In this study, the use of composites of zeolite NaY was examined both theoretically and experimentally for improvements in the water capacity and hydrophobicity. Salt impregnation and hydrothermal synthesis experiments were performed to prepare composites of zeolite NaY with LiCl/MgCl2 salts and activated carbon, respectively. Water capacity and hydrophobicity of zeolite NaY composites were generally superior to those of pure zeolite. Zeolite composites may be advantageous for enhancing adsorption capacity and hydrophobicity of zeolites while eliminating low stability and slow adsorption kinetics of other adsorbents. Interface between two different phases might indicate another opportunity to provide improved adsorption properties for zeolite composites. [ABSTRACT FROM AUTHOR]

Several tetrahydroxidohexaoxidopentaborate(1-) salts of N-substituted diimidazolium cations or N-substituted dipyrrolidinium cations linked through N-C6-N chains have been synthesized and characterized spectroscopically (NMR, IR) and by single-crystal XRD studies: [R(NC3H3N)(CH2)6(NC3H3N)R][B5O6(OH)4]2·xH2O (R = Me, x = 0 (1); R = Et, x = 3 (2); [Me(NC3H3N)(CH2(C6H4)CH2)(NC3H3N)Me][B5O6(OH)4]2 (3), [(C4H8N)(R)(CH2)6(R)(NC4H8)][B5O6(OH)4]2·xB(OH)3 (R = Me, x = 0 (4, two polymorphs); R = Et, x = 0 (5); R = Bu, x = 4 (6); R = allyl, x = 0 (7)). Representative samples (1 and 7) were also characterized by thermal (TGA/DSC) studies; compounds are thermally decomposed to B2O3 in air. Numerous anion-anion H-bonding interactions are present in the solid-state structures of 1–5 and 7 as giant anionic networks. Unusually, in 6 there are no R22(8) anion-anion interactions as the co-crystallized B(OH)3 bridges between all pentaborate anions. H-bonding interactions in 1–7 have been examined using Etter graph set analysis; C(8), C33(18), R22(8), R22(12) and R44(12) motifs have been identified. [ABSTRACT FROM AUTHOR]

In this study, the protein and salts distribution (Ca, P, Na and Mg) in processed cheese (PC) samples prepared with 180 or 360 mEq/kg of the calcium sequestering salts (CSS) disodium phosphate (DSP), disodium pyrophosphate (DSPP), sodium hexametaphosphate (SHMP) and trisodium citrate (TSC) was studied. For this purpose, a water-soluble extract (WSE) of PC samples was prepared. All PC samples contained 45–46% moisture, 26–27% fat and 20–21% protein and had a pH of 5.2 or 5.7. Ultracentrifugation slightly reduced the protein content of the WSE of PC, indicating that most protein in the WSE was non-sedimentable. At equal concentration of CSS, the protein content of the WSE was higher for PC at pH 5.7 compared to PC at pH 5.2. Approximately 55–85% of the Ca and P in the WSE of samples was 10 kDa-permeable for PC prepared with DSPP and SHMP. This suggests that the formation of non-permeable Ca–polyphosphate–casein complexes. For PC prepared with TSC, >90% of Ca in the WSE was 10 kDa-permeable, indicating that micellar disruption arises from sequestration of micellar Ca. These results indicate that the WSE method is an appropriate method to understand how salts present in PC are distributed. However, the WSE and ultracentrifugal supernatant of the WSE can include both soluble and protein-associated salts. Therefore, determining levels of salts in 10 kDa permeate of ultracentrifugal supernatant of the WSE is most appropriate. [ABSTRACT FROM AUTHOR]

Dynamic control of the motion in a catenane remains a big challenge as it requires precise design and sophisticated well‐organized structures. This paper reports the design and synthesis of a donor‐acceptor [2]catenane through mechanical interlocking, employing a crown ether featuring two dibenzylammonium salts on its side arms as the host and a cyclobis(paraquat‐p‐phenylene) (CBPQT ⋅ 4PF6) ring as the guest molecule. By addition of external acid or base, the catenane can form self‐complexed or decomplexed compounds to alter the cavity size of the crown ether ring, consequently affecting circumrotation rate of CBPQT ⋅ 4PF6 ring of the catenane. This study offers insights for the design and exploration of artificial molecular machines with intricate cascading responsive mechanisms. [ABSTRACT FROM AUTHOR]

The photoresponsive behavior of both mono- and dicationic bromide salts incorporated with 4-styrylpyridine was investigated. Upon exposure to UV light, the crystals showed dynamic changes, forming new organic salts by the [2 + 2] photodimerization process, which was elucidated by single crystal X-ray analysis and 1H NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A method for the construction of 2-fluoropyrazolo[1,5-a]pyridines through base-promoted [3+2] cycloaddition of N-aminopyridinium salts with gem-difluorostyrenes has been established. A range of N-heterocycles with 2-fluorinated pyrazo[1,5-a]pyridines were efficiently obtained in moderate to good yields. The impact of different substituents on the reaction was discussed in detail. The protocol shows great potential for the synthesis of valuable fluorinated compounds by utilizing gem-difluorostyrenes as fluoride-containing building blocks. [ABSTRACT FROM AUTHOR]

Tris(pentafluoroethyl)indane dihydrate, [In(C2F5)3(OH2)2], and the gallium analog, [Ga(C2F5)3(OH2)2], serve as transfer reagents for the In(C2F5)3 and Ga(C2F5)3 units, as illustrated by the preparation of salts of (pseudo)halogenotris(pentafluoroethyl)indate and ‐gallate anions, [M(C2F5)3)X]− (M=Ga, In; X=F, Cl, Br, I, CN, SCN). Due to the water tolerance and water solubility of [In(C2F5)3(OH2)2] and [Ga(C2F5)3(OH2)2], reactions can be performed in the presence of water or even in an aqueous medium. [ABSTRACT FROM AUTHOR]

A series of nine new soft salts based on two platinum(II) complexes, namely ([Pt(C^N)(CN)2]−[Pt(C^N)(en)]+) (en = ethane-1,2-diamine), has been developed and synthesized. Their photophysical properties in both solution and the solid state were described. All soft salt complexes exhibit phosphorescence emission with PLQY in the solid state up to 0.36. Most of these materials displayed aggregation-induced emission (AIE) or aggregation-induced emission enhancement (AIEE) in water/DMSO solutions as the water ratio increased. Structure–property relationships were analyzed in relation to emission properties. The presence of the free nitrogen atoms in soft salt complexes with a C^N pyrimidine-based ligand allowed for reversible sensitivity to acidic vapors, resulting in the quenching of phosphorescence emission. Additionally, for selected soft salts, we described reversible vapochromism behaviour, making these new materials interesting for multi-detection purposes in anti-counterfeiting applications. [ABSTRACT FROM AUTHOR]

Producing sp3‐hybridized carbon‐enriched molecules is of particular interest due to their high success rate in clinical trials. The installation of aliphatic chains onto aromatic scaffolds was accomplished by nickel‐catalyzed C(sp2)−C(sp3) cross‐electrophile coupling with arylsulfonium salts. Thus, simple non‐prefunctionalized arenes could be alkylated through the formation of aryldibenzothiophenium salts. The reaction employs an electrochemical approach to avoid potentially hazardous chemical redox agents, and importantly, the one‐pot alkylation proved also viable, highlighting the robustness of our approach. [ABSTRACT FROM AUTHOR]

A photoinduced three‐component reaction of thianthrenium salts, DABCO ⋅ (SO2)2, and benzyl ether substituted alkenes is developed, affording δ‐hydroxylsulfones with good functional group tolerance. This transformation proceeds through an anti‐Markovnikov hydrosulfonylation of alkenes under a mild reaction condition. Mechanism studies indicates that this reaction undergoes a radical pathway involving sulfur dioxide insertion and 1,5‐hydrogen transfer processes. [ABSTRACT FROM AUTHOR]