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Artificial membrane transporters that either use chalcogen bonds to facilitate transmembrane flux of anions or show high selectivity toward perchlorate anions are rare. In this work, we report on one such novel monopeptide-based transporter system, featuring both chalcogen bonds for highly efficient anion transport and high transport selectivity toward ClO4− anions. Structurally, these monopeptide molecules associate with each other via H-bonds to produce H-bonded 1D stack that not only one dimensionally but also directionally aligns the terminal bicyclic thiophene motifs to the same side. Functionally, these well-aligned thiophenes create a sulfur-rich transmembrane pathway, combinatorially fine-tunable to enable anions to efficiently cross the membrane in the increasing activity of Cl−

Copper(II) (cupric) and copper(I) (cuprous) azide are both very powerful primary explosives with good thermal stabilities. However, both suffer from extreme sensitivities, which makes them unsuitable for any application. One brilliant concept for the synthesis of new ecofriendly, non-water soluble, and very powerful primary explosives is the assembly of ligands in the coordination sphere of copper(II) azide. Blocking of possible coordination sites through endothermic azoles allows the desensitization of copper(II) azide and leads to compounds with manageable sensitivities. 13 different nitrogen-rich tri- and tetrazole derivatives were used for the synthesis of energetic copper(II) azide complexes. The water insoluble compounds are highly promising candidates for the replacement of lead and perchlorate containing primary explosives. For the characterization, the complexes were analyzed by single crystal X-ray diffraction, elemental analysis (EA), infrared (IR) spectroscopy, and differential thermal analysis (DTA) measurements with heating rates of 5 °C min−1. The bulk material purity of selected complexes was confirmed by X-ray powder diffraction. The sensitivities toward impact (IS), friction (FS), and electrostatic discharge (ESD) of all synthesized compounds were tested and determined according to BAM (Bundesanstalt fur Materialforschung und -prufung) standards. The most promising compounds were investigated in copper shell initiation experiments with PETN as main charge.

This article aims to inform the development of biological perchlorate remediation schemes for the preparation of safer human Mars habitats and contaminant-free in situ resource utilization (ISRU) f...

Electrochemical transformations of DDT into oxygen-incorporated products, amides and esters, catalyzed by the B12 derivative, heptamethyl cobyrinate perchlorate, have been developed under aerobic c...

PURPOSE In the case of a nuclear incident, the release of radioiodine must be expected. Radioiodine accumulates in the thyroid and by irradiation enhances the risk of cancer. Large doses of stable (non-radioactive) iodine may inhibit radioiodine accumulation and protect the thyroid ('thyroid blocking'). Protection is based on a competition at the active carrier site in the cellular membrane and an additional temporary inhibition of the organification of iodide (Wolff-Chaikoff effect). Alternatively, other agents like e.g. perchlorate that compete with iodide for the uptake into the thyrocytes may also confer thyroidal protection against radioiodine exposure.Biokinetic models for radioiodine mostly describe exchanges between compartments by first order kinetics. This leads to correct predictions only for low (radio)iodide concentrations. These models are not suited to describe the kinetics of iodine if administered at the dosages recommended for thyroid blocking and moreover does not permit to simulate either the protective competition mechanism at the membrane or the Wolff-Chaikoff effect. Models adapted for this purpose must be used. Such models may use a mathematical relation between the serum iodide concentration and a relative uptake suppression or a dependent rate constant determining total thyroidal radioiodine accumulation. Alternatively, the thyroidal uptake rate constant may be modeled as a function of the total iodine content of the gland relative to a saturation amount. Newer models integrate a carrier-mechanism described by Michalis-Menten kinetics in the membrane and in analogy to enzyme kinetics apply the rate law for monomolecular irreversible enzyme reactions with competing substrates to model the competition mechanism. An additional total iodide uptake block, independent on competition but limited in time, is used to simulate the Wolff-Chaikoff effect. CONCLUSION The selection of the best model depends on the issue to be studied. Most models cannot quantify the relative contributions of the competition mechanism at the membrane and the Wolff-Chaikoff effect. This makes it impossible or exceedingly difficult to simulate prolonged radioiodine exposure and the effect of repetitive administrations of stable iodine. The newer thyroid blocking models with a separate modeling of competition and Wolff-Chaikoff effect allow better quantitative mechanistic insights and offer the possibility to simulate complex radioiodine exposure scenarios and various protective dosage schemes of stable iodine relatively easily. Moreover, they permit to study the protective effects of other competitors at the membrane carrier site, like e.g. perchlorate, and to draw conclusions on their protective efficacy in comparison to stable iodine.

The combustion of pyrotechnic delay composition based on metallic fuel and perchlorate oxidizer involves complex reaction mechanisms and condensed phase heat release. Studies on the effect of aging...

Natural perchlorate (ClO4−) exists in many places on Earth, in lunar regolith, meteorites, and on the surface of Mars. Terrestrial natural ClO4− has widely variable Cl and O stable isotopic compositions (δ37Cl, δ18O, Δ17O). The δ18O and Δ17O values of ClO4− from the most hyper-arid locations co-vary. ClO4− from less arid areas has relatively little 17O excess and poor Δ17O-δ18O correlation. ClO4− from the Atacama Desert has unusually low δ37Cl (

A series of micro-mesoporous materials with nanosponge structure were synthesized in accelerated mode. The influence of the perchlorate oxyanion promoter on the materials characteristics was thoroughly investigated. It was shown that the formation of nanosponge structure with high amount of promoter occurs through the consecutive steps that can be easily detected. The effect of promoter concentration on the crystalline structure was demonstrated under simple hydrothermal conditions. A novel hydrothermal method was developed to synthesize the micro-mesoporous materials with nanosponge structure in 18 h.

The reaction of the tridentate ligand bis(2-picolyl)amine (BPA) with the chloride or perchlorate salts of zinc(II) ions yielded two zinc(II) complexes of the types: [(BPA)ZnCl2]·2H2O (1) and [(BPA)2Zn](ClO4)2 (2). The intermediate complex species, namely [(BPA)Zn(OH)(H2O)](ClO4) (3) and [(BPA)Zn-OP(= S)(CH3)2] (4) were successfully isolated separately in good yields and pure forms. Complexes 1–4 were characterized in the solid state by using elemental analyses, thermal analyses, FT-IR, and X-ray single crystal diffraction as well as in solution by using 1H NMR titration and cyclic voltammetry (CV). From X-ray structural and spectral features it can be concluded that the coordination environment around Zn(II) ion in 1 is a distorted square pyramidal geometry with τ5 value of 0.148. Whereas in 2, two picolyl chelates in the equatorial plane and two slightly longer axial pyridines are coordinated in a distorted octahedral trans-facial arrangement. Kinetic studies were performed on these complexes to evaluate their efficiency as functional hydrolase models for the hydrolysis of the toxic organophosphate insecticide, Fenitrothion. The pH-dependence of the catalytic rate gives a bell-shaped curve, which gives a strong proof that the hydroxoaqua complex [(BPA)Zn(H2O)(OH)]− 3 is the catalytically active species in the hydrolysis reactions than that of the octahedral [(BPA)2Zn]2+ with fully saturated coordination sphere.

Seven complex metal antimony tartrates have been synthesized in single crystal form by slowly evaporating aqueous solutions of potassium antimony tartrate (tartar emetic) and divalent metal nitrates or perchlorates. Crystal structures of these compounds all contain infinite chains formed by linking antimony tartrate dimers with divalent metal ions. While infinite chains of antimony tartrate dimers bridged by single Zn2+ ions or by double Mg2+ ions were reported previously, new types of chains with alternating single and double bridging cations are observed in this work.

An ammonium perchlorate (AP) and copper(II) benzoate pyrotechnic blue-flame composition was gradually “diluted” by adding an experimental perchlorate-free blue-flame composition based on aminoguanidinium nitrate (AGN), malachite, PVC powder and shellac resin. Flame’s luminous intensity and specific luminous intensity were recorded and analyzed. A copper-aminoguanidinium (CuAG) complex was also synthesized and tested as an energetic additive in perchlorate-free blue-flame composition. Green-flame color was observed when testing chlorine-free energetic compositions with CuAG.

The present study reports a physico-chemical characterization of the solutions of n-butylammonium perchlorate (C4H9NH3ClO4) (BAP) in acetonitrile–dimethylsulfoxide (AN–DMSO) binary mixtures. One objective is to optimize the extraction of components from waste propellants, BAP acting as a model compound. Combining the conductometric and viscometric approaches, quantitative analysis of molecular interactions is reported for solutions of BAP in AN–DMSO binary mixtures containing 0, 20, 40, 60, 80 and 100 mol% DMSO at different temperatures. Analysis of the conductance data to obtain limiting molar conductivities was done using the Onsager equation and the viscosity data were analysed using the Jones–Dole equation. From viscosity data, A and B-coefficients, B/VΦ values and the temperature derivative of B-coefficients, (dB/dT) are calculated. Using the appropriate division of limiting molar conductivity and B-coefficients of tetra-n-butylammonium tetraphenylborate (Bu4NBPh4) as a ‘reference’ electrolyte, the limiting ionic conductivities ( $$\lambda_{ \pm }^{{\text{o}}}$$ ) and B±-coefficients for individual ions have been estimated. The conductivity data is further utilized for obtaining different transport properties such as Walden product, solvated radii (rs), solvation numbers (ns), diffusion coefficients (D±) and ionic mobility (µi) of the ions. The influence of the solvent composition on the solvation of ions was discussed in terms of the composition dependence of solvated radii, Walden product, solvation numbers and viscosity B±-coefficients. In the light of all these parameters, the existence of ion–ion and ion–solvent interations in the investigated system has been identified. Eyring transition state theory has also been used to calculate various activation parameters of viscous flow. Results show preferential solvation of butylammonium ( $${\text{C}}_{4} {\text{H}}_{9} {\text{NH}}_{3}^{ + }$$ ) ions by DMSO in the AN rich region and by AN in the DMSO rich region of the solvent mixtures at all the temperatures studied.

Accurate knowledge of the electroosmotic flow mobility is crucial for the determination of effective electrophoretic mobilities in capillary electrophoresis. The addition of a neutral marker to the sample is a common method for electroosmotic flow mobility measurement. Nevertheless, the neutral marker can also exhibit electrophoretic mobility due to its interactions with background electrolyte constituents. In our previous study, we have shown the effect of different cations in background electrolytes with a fixed anion. In this work, the relative mobility of neutral compounds, either those commonly used as electroosmotic flow markers or their structurally related molecules, was measured in the presence of various anions in the background electrolyte with sodium as a fixed cation at pH 4.5. The mobility of eight compounds, formamide, N-methylformamide, N,N-dimethylformamide, acrylamide, N,N-dimethylacrylamide, N-methylacetamide, mesityl oxide, and dimethyl sulfoxide, was related to the mobility of thiourea. The studied anions were chloride, perchlorate, sulfate, and acetate. The results revealed a dramatic effect of perchlorate. The interaction with perchlorate strengthens significantly with the increasing number of non-polar moieties, such as methyl or acryl, present in the marker molecule. On the other hand, sulfate showed a very weak effect on all the studied compounds.

The temperature dependence of the relaxation time of imidazolium perchlorate (Im-ClO4) was calculated from the pseudospin-phonon coupled (PS) and the energy fluctuation (EF) models close to the first-order phase transition temperature of 247 K. This calculation was performed in terms of the proton second moment M2 that was associated with the order parameter which was predicted from the mean-field theory. Our results were in good agreement with the observed data. In addition, values of the activation energy were deduced in terms of the Arrhenius plot using our calculated values of the relaxation time from both PS and EF models.

Studies of salt effects on enzyme activity have typically been conducted at standard temperatures and pressures, thus missing effects which only become apparent under non-standard conditions. Here we show that perchlorate salts, which are found pervasively on Mars, increase the activity of α-chymotrypsin at low temperatures. The low temperature activation is facilitated by a reduced enthalpy of activation owing to the destabilising effects of perchlorate salts. By destabilising α-chymotrypsin, the perchlorate salts also cause an increasingly negative entropy of activation, which drives the reduction of enzyme activity at higher temperatures. We have also shown that α-chymotrypsin activity appears to exhibit an altered pressure response at low temperatures while also maintaining stability at high pressures and sub-zero temperatures. As the effects of perchlorate salts on the thermodynamics of α-chymotrypsin’s activity closely resemble those of psychrophilic adaptations, it suggests that the presence of chaotropic molecules may be beneficial to life operating in low temperature environments.

Surface-fixation induced emission is a fluorescence enhancement phenomenon, which is expressed when dye molecules satisfy a specific adsorption condition on the anionic clay surface. The photophysical behaviors of two types of cationic acridinium derivatives [10-methylacridinium perchlorate (Acr+) and 10-methyl-9-phenylacridinium perchlorate (PhAcr+)] on the synthetic saponites with different anionic charge densities were investigated. Under the suitable conditions, the fluorescence quantum yield (Φf) of PhAcr+ was enhanced 22.3 times by the complex formation with saponite compared to that in water without saponite. As the inter-negative charge distance of saponite increased from 1.04 to 1.54 nm, the Φf of PhAcr+ increased 1.25 times. In addition, the increase in the negative charge distance caused the increase in the integral value of the extinction coefficient and the radiative deactivation rate constant (kf) and the decrease in the nonradiative deactivation rate constant. It should be noted that the 2.3 times increase in kf is the highest among the reported values for the effect of clay. From these results, it was concluded that the photophysical properties of dyes can be modulated by changing the charge density of clay minerals.

Ditopic ligand with coordination centers of different types was synthesized. Ligand contains 1,10-phenanthroline fragment for Ru(II) coordination and azadithiacrown ether moiety for Cu(II) cation binding. At first step, new ruthenium complex was synthesized and then its complexation with Cu(II) perchlorate was studied by optical and electrochemical means. The complex obtained in this work represents a rare type of bimetallic complexes, in which both cations are located in one ligand system, but their effect on each other is measurable.

Perchlorate is an oxidant inorganic pollutant that is resistant to degradation by biological and photocatalytic processes. The present work introduces the degradation of perchlorate from aqueous solution by a new composite of Ni/Fe nanoparticles (Ni/Fe NPs) supported on organoclay. In this study, first, the Ni/Fe NPs were synthesized in the presence of bentonite clay as support by borohydride reduction method. Bentonite clay containing reducing magnetic nanoparticles was modified with cetylpyridinium chloride (CPC) to prepare reducing magnetic organoclay (RMO). Then, it was used for simultaneous adsorption and degradation of perchlorate from the aqueous media. The prepared organoclay was characterized by scanning electron microscopy. energy-dispersive X-ray spectroscopy and X-ray powder diffraction. The main factors in perchlorate removal, such as amount of RMO, degradation time, molar ratio of Ni : Fe, NPs dosage and pH were optimized using the experimental design based on the central composite design (CCD) method. Under optimal conditions. the degradation efficiency was close to 100%. Also, the reduction degradation of perchlorate was well fitted with a pseudo first order kinetic model with a rate constant of 0.0299 min–1 and an activation energy of 5.94 kJ/mol. In this research, it was shown that the prepared nanocomposite has a faster degradation rate than nano zero-valent iron (nZVI) at room temperature. The synthesized nanocomposite was successfully used to degrade perchlorate from well water and industrial wastewater samples. Finally, the study presents a new catalytic reducing nanocomposite for environmental remediation of oxidant-resistant pollutants, such as perchlorate from aqueous media.

Chromium (Cr) (VI) is a toxic, mutagenic, and carcinogenic water pollutant. The standard ion chromatography (IC) method for quantification of Cr (VI) in water samples is Environmental Protection Agency Method 218.7, which requires postcolumn derivatization with 1,5-diphenylcarbazide and UV-Vis spectroscopy detection. Method 218.7 is Cr (VI) specific; thus, it does not allow detection of co-occurring natural and anthropogenic anions in environmental media. In this study, we developed an isocratic IC method with suppressed conductivity detection, a Metrohm Metrosep A Supp 7 column, and sodium carbonate/acetonitrile as mobile phase for simultaneous quantification of Cr (VI), ClO4−, As (V) as arsenate, Se (VI) as selenate, and the common anions F–, Cl–, NO2−, NO3−, and SO42−. The determination coefficient for every analyte was >0.99 and the method showed good accuracy in quantification. Cr (VI), As (V), Se (VI), and ClO4− limit of detection and limit of quantification were 0.1–0.6 μg/L and 0.5–2.1 μg/L, respectively. Recovery of Cr (VI) in various aqueous samples (tap water, surface water, groundwater, and wastewater) was between 97.2% and 102.8%. Overall, most analytes showed acceptable recovery (80–120%) in the environmental samples tested. The IC method was applied to track Cr (VI) and other anion concentrations in laboratory batch microcosms experiments with soil, surface water, and anaerobic medium. The IC method developed in this study should prove useful to environmental practitioners, academic and research organizations, and industries for monitoring low concentrations of multiple anions in environmental media, helping to decrease the sample requirement, time, and cost of analysis.

Abstract Indoline spiropyran containing an σ-acceptor chlorine atom in 6′ position of the 2H-chromene part of the molecule was synthesized and studied. The use of 1,2,3,3-tetramethyl-3H-indolium perchlorate as a starting compound made it possible to achieve higher product yields as compared to previous studies. The molecular structure of the compound was established by single crystal X-ray diffraction analysis. The features of the crystal structure and intermolecular interactions were investigated using CrystalExplorer17 software package. The photochromic behavior in acetonitrile solution was studied for the first time. It was found that the merocyanine form of spiropyran is characterized by an absorption maximum at 592 nm, which is 37 nm closer to the range of the “biological window” in comparison with the nitro-substituted analog.

Complexes of Co(II), [Co(C 26 H 24 N 8 O 2 )]·(ClO 4 ) 2 ·(H 2 O) 2 (1), and Cu(II), [Cu(C 26 H 23 N 8 O 2 )]·(ClO 4 ) (2), have been synthesized. The prepared two compounds were characterized by elemental analysis, infrared and their structures were determined by single-crystal X-ray diffraction. The compound 1 crystallizes in the triclinic space group P -1 with the following unit cell parameters: a = 8.880 (5) A, b = 10.529 (5) A, c = 18.430 (5) A, α = 99.407 (5)°, β = 102.174 (5)°, γ = 100.652 (5)°, V = 1618.2 (13) A 3 , Z = 2, T = 293(2), μ(MoKα) = 0.77 mm -1 , D calc = 1.582 g/cm 3 , 16135 reflections measured (5.050° ≤ 2q ≤ 59.152°), 7648 unique, R int = 0.034 which were used in all calculations. The final R 1 was 0.066 (I ≥ 2σ(I)) and wR 2 was 0.22 (all data). The compound 2 crystallizes in the monoclinic space group P 2 1 /c with the following unit cell parameters : a = 11.652 (5) A, b = 16.540 (5) A, c = 14.512 (5) A, β = 93.495 (5)°, V = 2791.6 (18) A 3 , Z = 4, T = 293(2), μ(MoKα) = 1.05 mm -1 , D calc = 1.768 g/cm 3 , 15592 reflections measured (5.624° ≤ 2θ ≤ 58.804°), 6630 unique, R int = 0.025 which were used in all calculations. The final R 1 was 0.050 (I ≥ 2σ(I)) and wR 2 was 0.144 (all data). In both complexes, the ligand acts in a tridentate fashion. In the structure of the mononuclear complex 1, the Co(II) cation is coordinated by two ligand molecules. The basal plane around the Co(II) cation is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms. Two imino nitrogen atoms occupy the apical positions of the distorted square-pyramidal geometry. The mononuclear 2 consists of a Cu(II) coordinated by one ligand and one monodeprotonated ligand molecule. The metal center lies in a distorted square bipyramidal environment. The basal plane around the Cu(II) is occupied by two pyridine nitrogen atoms and two carbonyl oxygen atoms, the apical position being occupied by the two imino nitrogen atoms.

Metal-organic frameworks (MOFs) have been proposed as emerging fillers for composite polymer electrolytes (CPEs). However, MOF particles are usually served as passive fillers that yield limited ionic conductivity improvement. Building continuous MOF reinforcements and exploiting their active roles remain challenging. Here we demonstrate the feasibility of engineering fast Li+ conduction within MOF on molecule conception. Two-dimensional Cu(BDC) MOF is selected as an active filler due to its sufficient accessible open metal sites for perchlorate anion anchoring to release free Li+, verified by theoretical calculations and measurements. A novel Cu(BDC)-scaffold-reinforced CPE is developed via in situ growth of MOF, which provides fast Li+ channels inside MOF and continuous Li+ paths along the MOF/polymer interface for high Li+ conductivity (ambient 0.24 mS cm-1) and enables high mechanical strength. Stable cycling is achieved in solid-state Li-NCM811 full cell using the MOF-reinforced CPE. This molecule-basis Li+ conduction strategy brings new ideas for designing advanced CPEs.

The amination of 3,4,5-triamino-1,2,4-triazole with O-tosylhydroxylamine yielded the nitrogen-rich 1,3,4,5-tetraamino-1,2,4-triazolium cation as its tosylate salt. Subsequent metathesis reactions produced energetic salts with various energetic anions, including perchlorate, nitrate, nitrotetrazolate, and bistetrazolate diolate. All energetic salts possess relatively high heats of formation, thermal sensitivities, and detonation velocities and pressures. The prepared energetic salts were characterized chemically using single-crystal X-ray crystallography, elemental analysis, and 1H NMR, 13C NMR, and IR spectroscopy and energetically by measuring their thermal, impact, and friction sensitivities. 15N NMR was carried out on the tosylate salt. Energetic performances were determined by a combined experimental-computational method using calculated heats of formation and experimental crystal densities.

Perchlorate has been acknowledged as a health threat due to its ability to interfere with iodine uptake by the thyroid gland. Infants and developing newborns have been considered as the most vulnerable groups to the perchlorate toxicity. A crucial source of perchlorate ingestion are powdered infant formulas. This study was designed to measure perchlorate content in thirty-one powdered infant formulas available on the Polish market. A rapid and sensitive ion chromatography method – conductivity cell detection – was applied to determine ClO 4 − {\rm{ClO}}_4^ - content. Limit of detection (0.150 µg/L) and limit of quantification (0.450 µg/L) were assessed. Collected samples were classified by the age of consumers: first stage, until the baby is six months old and follow-on formula for older children. Geometric mean of perchlorate concentration of 1.041 µg/L and 0.857 µg/L in the groups of the first stage and follow-on formulas were calculated, respectively. A health risk assessment revealed that the Tolerable Daily Intake (TDI) for perchlorate (0.3 µg/kg body weight/day) was exceeded only in a few milk samples. The findings suggest that perchlorate contamination of powdered infant formulas may not to be an immediate health issue, yet testing for ClO 4 − {\rm{ClO}}_4^ - should continuously be conducted. To the best of our knowledge, this is the first study concerning perchlorate content in infant formulas in Poland.

Проведено вивчення хіміотерапевтичної ефективності 2-феніл-4-(1-піролідиніл)-6-ізопропілтіо-5-піримідилтрифенілфосфоній перхлорату, яка відноситься до гетероциклічних фосфонієвих сполук з піримідиновим циклом, в експерименті на моделі генералізованої стафілококової інфекції. Отримано позитивні результати, що дадуть право робити висновок про можливість використання їх у клінічних дослідженнях і створення на їх основі перспективних антибактеріальних та антисептичних препаратів.

We report the synthesis, single-crystal structure, solid-state ultraviolet-visible-near-infrared spectroscopy, and theoretical calculations on the first trivalent plutonium crown ether inclusion complex, [(H3O)(18-crown-6)][Pu(H2O)4(18-crown-6)](ClO4)4·2(H2O) (denoted as PuIII-18C6). Single-crystal X-ray diffraction reveals that PuIII-18C6 crystallizes in the orthorhombic space group of Pccn, which is assembled by independent ionic pairs including [Pu(H2O)4(18-crown-6)]3+, [(H3O)(18-crown-6)]+, and perchlorate anions. The plutonium atom is fully encapsulated within the cavity of the 18-crown-6, generating a distorted bicapped square antiprism geometry. The theoretical evaluation confirms that weak Pu-O dative bond is involved between PuIII ions with 18-crown-6. This work may deepen the understanding of the host-guest interactions between trivalent transuranic and macrocyclic ligands.

Perchlorate (ClO4-) is a pervasive, harmful, and inert anion on both Earth and Mars. Current technologies for ClO4- reduction entail either harsh conditions or multicomponent enzymatic processes. Herein, we report a heterogeneous (L)Mo-Pd/C catalyst directly prepared from Na2MoO4, a bidentate nitrogen ligand (L), and Pd/C to reduce aqueous ClO4- into Cl- with 1 atm of H2 at room temperature. A suite of instrument characterizations and probing reactions suggest that the MoVI precursor and L at the optimal 1:1 ratio are transformed in situ into oligomeric MoIV active sites at the carbon-water interface. For each Mo site, the initial turnover frequency (TOF0) for oxygen atom transfer from ClOx- substrates reached 165 h-1. The turnover number (TON) reached 3840 after a single batch reduction of 100 mM ClO4-. This study provides a water-compatible, efficient, and robust catalyst to degrade and utilize ClO4- for water purification and space exploration.

Hydrophilic interaction liquid chromatography is an alternative liquid chromatography mode for separation of polar compounds. In the recent years, this liquid chromatography mode has been recognized as an important solution for the analysis of compounds not amenable to reverse phase chromatography. In this work, we evaluated three different hydrophilic liquid chromatography stationary phases for the determination of 14 highly polar anionic molecules including pesticides such as glyphosate, glufosinate, ethephon and fosetyl, their main metabolites, and bromide, chlorate, and perchlorate. Several mobile phase compositions were evaluated combined with different gradients for the chromatographic run. The two columns that presented the best results were used to assess the performance for the determination of the 14 compounds in challenging highly complex feed materials. Very different matrix effects were observed for most of the compounds in each column, suggesting that different interactions can occur. Using isotopically labeled internal standards, acceptable quantitative performance and identification could be achieved down to 0.02 mg kg−1 (the lowest level tested) for most compounds. While one column was found to be favorable in terms of scope (suited for all 14 compounds), the other one was more suited for quantification and identification at lower levels, however, not for all analytes tested.

The molecular and crystal structure of 1H-1,2,4-triazolium perchlorate, C2H4N3 +·ClO4 −, was determined as detailed crystallographic data had not been available previously. The structure has monoclinic (P21/m) symmetry. It is of interest in the field of energetic compounds because nitrogen-rich azoles are the backbone of high-density energetic compounds, and salt-based energetic materials can exhibit preferential energy-release behaviour. The bond angles of the 1,2,4-triazolium cation in this study were similar to those of a cationic triazole ring reported previously and were different from those of the neutral triazole ring. This study contributes to the available data that can be used to analyse the relationship between the structures and properties of energetic materials.

The crystal structure of the title salt, C20H42N4 2+·2ClO4 −, has been determined using synchrotron radiation at 220 (2) K. The structure determination reveals that protonation has occurred at diagonally opposite amine N atoms. The asymmetric unit comprises one half of the organic dication, which lies about a center of inversion, and one perchlorate anion. The macrocyclic dication adopts the most stable endodentate trans-III conformation. The crystal structure is stabilized by intramolecular N—H...N, and intermolecular N—H...O and C–H...O hydrogen bonds involving the macrocycle N—H and C—H groups as donors and the O atoms of perchlorate anions as acceptors, giving rise to a three-dimensional network.

This work describes the use of simple zinc(II) salts (ZnCl2, ZnCO3, Zn(OAc)2, ZnO, Zn(ClO4)2, Zn(TfO)2, and Zn(BF4)2) as effective catalysts for the esterification of fatty acids with long-chain alcohols and simple polyols through a homogeneous system that allows the gradual and selective removal of water. The results show that the catalytic activity depends on the nature of the counterion: the most effective are the salts with poorly coordinating anions (perchlorate and triflate) or containing basic Brønsted anions (oxide, acetate, and carbonate). However, only with the latter is it possible to fully recover the catalyst at the end of each run, which is easily filtered in the form of zinc carboxylate, given its insolubility in the ester produced. In this way, it is possible to recycle the catalyst numerous times, without any loss of activity. This beneficial prerogative couples the efficiency of the homogeneous catalysis with the advantage of the heterogeneous catalysis. The process is, therefore, truly sustainable, given its high efficiency, low energy consumption, ease of purification, and the absence of auxiliary substances and byproducts., Simple zinc(II) salts are effective and recyclable catalysts for the solvent-free esterification of fatty acids with medium−long-chain alcohols.

Perchlorate in various foods continuously arouses public health concern. Bioavailability is a critical parameter to better estimate perchlorate exposure from diets. In this study, perchlorate bioavailability in five foods was determined in an in vivo mouse model and compared with in vitro bioaccessibility/bioavailability. The estimated in vivo perchlorate bioavailability for different foods ranged from 18.01 ± 4.53% to 45.60 ± 7.11%, with the order lettuce > pork > rice > milk powder > soybean. Moisture, fiber, and fat in foods were identified as critical factors affecting perchlorate bioavailability (correlation r = 0.71, 0.52, and -0.67, respectively). Linear regression analysis revealed that the in vitro perchlorate bioavailability determined using the Caco-2 cell model has the potential to estimate the in vivo perchlorate bioavailability in foods (R2 = 0.67, slope = 1.33, and y intercept = 4.99). These findings provide insights into the effects of the food matrices on perchlorate bioavailability and could contribute to decrease the uncertainty regarding perchlorate dietary exposure risk assessment.

Health issues related to aquifer contamination with perchlorate are a growing concern in drinking water management. This study describes perchlorate transport and degradation processes from a contaminated stream toward drinking water pumping wells. Investigations are based on laboratory experiments and field measurements conducted at a well field near Bordeaux (France) in a heterogeneous carbonate aquifer interacting with a stream. Field measurements facilitated the characterization of perchlorate contamination and stream-to-aquifer flow. Experiments on columns of streambed sediments conducted in the laboratory confirmed that perchlorate had been degraded in the hyporheic zone. A one-dimensional reactive transport model was implemented to estimate Monod kinetic rates, which account for the inhibition of perchlorate degradation by nitrate. The estimated half-saturation constant for perchlorate $$ \Big({k}_{1/2}^{\mathrm{Pcl}} $$ ) is 6.93 10−9 mol L−1 and the estimated maximum specific degradation rate ( $$ {k}_{\mathrm{max}}^{\mathrm{Pcl}} $$ ) ranges between 10−5 and 4.0 10−3 mol L−1 day−1. Despite degradation in the hyporheic zone, perchlorate-contaminated stream water reaches drinking-water-production units. Such contamination highlights the effects of preferential flow paths between the stream and the pumping wells and significant hydraulic gradients caused by drawdowns. In such contexts, in spite of a good potential for degradation, riverbank filtration may not be effective for the protection of drinking water wells. Lessons from this study also reveal that contamination monitoring can be misleading: low concentrations can be reported in monitoring wells between the contaminant source and the production wells, but the latter may yet be contaminated.

Perchlorate, emerging pollution with thyroid toxicity, has a high detection rate in fresh tea leaves. What needs attention is that the uptake characteristic is insufficiently understood. Herein, the uptake, accumulation, and translocation of perchlorate in a tea plant-hydroponic solution system were investigated, of which the mechanism was further lucubrated by subcellular distribution. The perchlorate concentration in tea tissues is ramped up along with the increase in the exposure level and time. The bioaccumulation factor of tea tissues followed the rank: mature leaves > tender leaves > roots. After the seedlings have been transplanted to a perchlorate-free solution, the perchlorate in mature leaves is reduced significantly, accompanied by a progressive increase in perchlorate in new shoots and solutions. The cell-soluble fractions are the major reservoir of perchlorate both for roots (>59%) and leaves (>76%), which precisely explained the translocation within the tea plant-hydroponic solution system. These results not only illuminate the uptake characteristic in tea plants but also improve the understanding of the behavior of perchlorate in higher plants.

The presence of perchlorate ions on Mars raises the question of how these ions influence the biochemistry of any contaminant life introduced into the martian environment, or what selection pressures perchlorate ions exert on any environment that contains these ions, such as the Atacama Desert. In this study, we investigated the structure, stability, and enzyme activity of the model enzyme α-chymotrypsin in the presence of five Mars relevant salts, MgSO4, MgCl2, Mg(ClO4)2, Ca(ClO4)2, and NaClO4. We found that all the perchlorate salts reduced the enzyme activity of α-chymotrypsin in a concentration-dependent manner, with Mg(ClO4)2 and Ca(ClO4)2 having the greatest effect. This observation extends to our structural studies, which show that 1 M Mg(ClO4)2 and Ca(ClO4)2 greatly alter the tertiary structural environment of α-chymotrypsin. We also found that all the perchlorate salts assayed reduced the melting temperature of α-chymotrypsin, whereas the sulfate and chloride salts were able to increase the protein melting temperature. We also demonstrated that a brine containing both perchlorate and sulfate ions exerts the same deleterious effects on α-chymotrypsin's melting temperature and enzyme activity as that of a perchlorate-only brine. This suggests that the perchlorate salts exert a dominant, deleterious effect on protein biochemistry. These results indicate that although perchlorate salts are beneficial to the presence of liquid water due to low eutectic points, they also hamper the habitability of their own environment. Life in such brines would, therefore, have to adapt its cellular machinery to the perchlorate ion's presence or find a way of excluding it from said machinery.

The combination of two bidentate Ph2P(O)CH2C(O)N(Alk)-fragments in one molecule via amide nitrogen atom by alkylene bridge has been found to result in marked increase in REE(III) extraction from perchlorate solutions. The stoichiometry of recovered complexes has been determined. The effect of extractant structure, HClO4 concentration in aqueous phase, and organic solvent nature on the efficiency of REE(III) ions extraction into organic phase has been considered.

The evaluation of cell's weatherability is of practical interest. To further improve the soluble lead flow battery's weatherability, physiochemical properties of electrolytes containing fluoborate, perchlorate, methanesulfonate and trifluoromethanesulfonate are investigated from −60 to 50 °C. Activities of CF3SO3H and HClO4 are poor in trifluoromethanesulfonate and perchlorate solutions due to common anion effect. The solubility of lead salt can be improved by increasing temperature, but worsened by increasing acid's content. With the temperature increasing, the conductivity is enhanced, and the viscosity is lowered for four solutions. The same results have been found by increasing acid's content except for CF3SO3H. The high energy efficiency can be achieved for cells over −40–0 °C using fluoborate and perchlorate solutions, 73.2% at −40 °C and 78.1% at −30 °C respectively. Over the temperature range of 20–50 °C, the cells with methanesulfonate and trifluoromethanesulfonate solutions have good performance, 77.4% and 73.7% at 50 °C respectively.

Ionic liquids are regarded as one of the most prodigious materials for sustainable technological developments with superior performance and versatility. Hence, in this study, we have reported the design and synthesis of electroactive disubstituted ferrocenyl ionic liquids (Fc-ILs) with two different counter anions and demonstrated the significance of their anion tuneable physicochemical characteristics towards multifunctional electrochemical applications. The Fc-IL synthesized with chloride counter anion (Fc-Cl-IL) displays water-solubility and can be used as a redox additive in the fabrication of supercapacitor. Supercapacitor device with Fc-Cl-IL based redox electrolyte exhibits outstanding energy and power densities of 91 Wh kg−1 and 20.3 kW kg−1, respectively. Meanwhile, ferrocenyl IL synthesized with perchlorate anion (Fc-ClO4-IL) exhibits water-insolubility and can serve as a redox mediator towards construction of a glucose biosensor. The biosensor comprising Fc-ClO4-IL is able to detect glucose at an exceptionally lower potential of 0.2 V, with remarkable sensitivity and selectivity. This study implies that the introduction of electroactive ILs could afford supercapacitor devices with high energy and power densities and biosensors with less detection potential.

Herein, three novel sulfonic-functionalized Bronsted acidic ionic liquids containing perchlorate anion counterparts were prepared and well characterized using FTIR, 1H and 13C NMR, Electro-Spray Ionization Mass Spectrometry (ESI-MS), elemental analysis (CHNS) and TG techniques. These ionic liquid catalysts were prepared through simple and ecofriendly procedures and then applied as efficient catalysts with high yields under solvent-free conditions for the synthesis of 4-substituted coumarins through the Pechmann condensation of different phenols and β-ketoesters. Compared to previous works, the proposed method offers several benefits, such as cleaner reactions, decreased reaction times, high yields, and the lack of laborious workup or purification procedures. Particularly, these catalysts make the condensation of less activated phenols feasible. Besides the described benefits, this advanced protocol was applied successfully for the synthesis of coumarins from γ-lactones such as 3-acetyldihydrofuran-2(3H)-one. The simplicity in operation, applicability and feasibility of this protocol for diverse substrates make it an efficient alternative to conventional methods.

Ruthenium half-sandwich complexes [Cp*Ru (diene compound)]+X− containing various commercially available diene compounds as ligands were tested as catalysts for the hydrogenation of diene compounds. Complexes containing acyclic, cyclic, bicyclic dienes, and α,β-unsaturated carboxylic acids and their derivatives as diene ligands were successfully prepared. The anionic part of the complexes (X−) was represented by triflate, perchlorate and tetrafluoroborate ions. Hydrogenations were carried out in homogeneous and heterogeneous arrangements. The desired products with Z-configuration of the double bond were formed with high selectivity (95–99%) in both cases. It was found out that selectivity was influenced neither by the type of diene ligand nor by the type of the anionic part of the complex. The hydrogenation rate was influenced by the type and the size of the diene ligand. The rate of hydrogenation of diene using complexes containing isolated cyclic or bicyclic ligands was the highest. The lowest reaction rates were observed using complexes with acyclic dienes. The influence of the type of the anionic part of the complex on the reaction rate was also studied. The lowest rate of hydrogenation was observed using complexes with tetrafluoroborate anion. The difference in reaction rates using complexes with triflate and perchlorate anions was not significant. This work added important information for the understanding the mechanism of diene hydrogenation using ruthenium half-sandwich complexes.

A new type of crystalline solid, termed “solvate sponge crystal”, is presented, and the chemical basis of its properties are explained for a melt- and press-castable solid sodium ion conductor. X-ray crystallography and atomistic simulations reveal details of atomic interactions and clustering in (DMF)3NaClO4 and (DMF)2NaClO4 (DMF = N-N′-dimethylformamide). External pressure or heating results in reversible expulsion of liquid DMF from (DMF)3NaClO4 to generate (DMF)2NaClO4. The process reverses upon the release of pressure or cooling. Simulations reveal the mechanism of crystal “juicing,” as well as melting. In particular, cation–solvent clusters form a chain of octahedrally coordinated Na+–DMF networks, which have perchlorate ions present in a separate sublattice space in 3 : 1 stoichiometry. Upon heating and/or pressing, the Na+⋯DMF chains break and the replacement of a DMF molecule with a ClO4− anion per Na+ ion leads to the conversion of the 3 : 1 stoichiometry to a 2 : 1 stoichiometry. The simulations reveal the anisotropic nature of pressure induced stoichiometric conversion. The results provide molecular level understanding of a solvate sponge crystal with novel and desirable physical castability properties for device fabrication., Stimuli-responsive “solvate-sponge”-(DMF)3NaClO4 exhibits linear chains of DMF–Na+ ions with ClO4− anions in the interstitial space. At increased pressure or temperature, DMF is expelled (reversibly), resulting in a new stoichiometry-(DMF)2NaClO4.

Previous studies demonstrated that methane can be used as an electron donor to microbially remove various oxidized contaminants in groundwater. Natural gas, which is more widely available and less expensive than purified methane, is potentially an alternative source of methane. However, natural gas commonly contains a considerable amount of ethane (C2H6) and propane (C3H8), in addition to methane. It is important that these gaseous alkanes are also utilized along with methane to avoid emissions. Here, we demonstrate that perchlorate (ClO4-), a frequently reported contaminant in groundwater, can be microbially reduced to chloride (Cl-) driven by C2H6 or C3H8 under oxygen-limiting conditions. Two independent membrane biofilm reactors (MBfRs) supplied with C2H6 and C3H8, respectively, were operated in parallel to biologically reduce ClO4-. The continuous ClO4- removal during long-term MBfR operation combined with the concurrent C2H6/C3H8 consumption and ClO4- reduction in batch tests confirms that ClO4- reduction was associated with C2H6 or C3H8 oxidation. Polyhydroxyalkanoates (PHAs) were synthesized in the presence of C2H6 or C3H8 and were subsequently utilized for supporting ClO4- bio-reduction in the absence of gaseous alkanes. Analysis by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) showed that transcript abundance of bmoX (encoding alpha hydroxylase subunit of C2H6/C3H8 monooxygenase) was positively correlated to the consumption rates of C2H6/C3H8, while pcrA (encoding a catalytic subunit of perchlorate reductase) was positively correlated to the consumption of ClO4-. High-throughput sequencing targeting 16S rRNA, bmoX, and pcrA indicated that Mycobacterium was the dominant microorganism oxidizing C2H6/C3H8, while Dechloromonas may be the major perchlorate-reducing bacterium in the biofilms. These findings shed light on microbial ClO4- reduction driven by C2H6 and C3H8, facilitating the development of cost-effective strategies for ex situ groundwater remediation.