Acetonitrile Solvent Research Articles

Synthesis of novel conducting triblock copolymer poly(thiophene-co-pyrrole-co-aniline) by chemical oxidative polymerization method for gas sensor application

The conducting triblock copolymer P(Th-co-Py-co-Ani) of thiophene (Th), pyrrole (Py), and aniline (Ani) has been synthesized by chemical oxidative polymerization method using anhydrous iron (III) chloride (FeCl3) as an oxidizing agent in presence of acetonitrile solvent at 0–8°C. Characterizations of the synthesized copolymer were performed by Attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction analysis (PXRD), UV-Vis spectroscopy, elemental analysis (CHNS), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). Notably, UV-Vis spectroscopy revealed that triblock copolymers exhibit highly conjugated conducting polymer backbone, essential for its electrical conductivity and suitability for various applications. The prepared P(Th-co-Py-co-Ani) material was investigated for the gas sensing property of several gases such as ammonia, acetone, carbon monoxide, ethanol and methane. The gas sensing study revealed that P(Th-co-Py-co-Ani) demonstrates promising gas sensing capabilities, particularly at room temperature.

Experimental and simulation study on the solubility of 1-naphthylamine in twelve neat solvents

To meet the demand of separating and purifying 1-naphthylamine from the reaction production and filling the solubility data gap, the solubility of 1-naphthylamine in twelve pure solvents (acetone, acetonitrile, ethyl acetate, n-butyl acetate, cyclohexane, n-heptane, methanol, ethanol, n-propanol, iso-propanol, n-butanol, and iso-butanol) was experimentally investigated in the range from 273.15 K to 308.15 K. It was found that the solubility of 1-naphthylamine increases markedly with increasing temperature in all solvent systems. The maximum solubility was 0.8978 (in the solvent of acetone,T = 308.15 K) and the minimum solubility was 0.005485 (in the solvent of n-heptane, T = 273.15 K). Then the experimental solubility data was correlated by the modified Apelblat model, Van't Hoff model, NRTL model, Wilson model, and Margules model. ARD% was calculated to assess the accuracy of the five equations and the results indicated that the modified Apelblat model fits optimally with an average ARD% value of 1.62 %. The effects of various physicochemical properties such as solvent polarity, hydrogen bond donor, hydrogen bond acceptor, and cohesive energy density on solute dissolution behavior were explored. In addition, the apparent thermodynamic properties of 1-naphthylamine in different solvents were analyzed based on modified Van’t Hoff model, which indicated the dissolution process of 1-naphthylamine in selected solvents is endothermic and entropy-driving. Finally, the effect of intermolecular interactions on the dissolution behavior was investigated at the molecular scale through molecular dynamics simulation studies, including molecular electrostatic potential surface, solvation free energy and radial distribution function analysis. This work will provide a fundamental guidance for the crystallization, separation, and purification of 1-naphthylamine.

Automatic Control of Nucleation and Crystal Growth Using Online Raman Analyzer

The accurate determination of crystal formation during crystallization is crucial for obtaining crystal products with consistent quality and quantity. In this study, we aimed to identify the feasibility of using Raman spectroscopy to monitor the crystal growth stage in the crystallization process using cephalosporin intermediate 7-ACT as an example molecule. By observing the changes in the characteristic peak of the 7-ACT crystal (504 cm−1) and the characteristic peak of the solvent acetonitrile (914 cm−1), a correlation between the crystal growth stage and the change in the Raman intensity of the crystal solution was discovered. The determination of the optimal starting time for the crystal growth stage through a Raman analyzer significantly improves the consistency of crystal product quality. This led to a fivefold reduction in the variation in the weight and water content of the final 7-ACT crystal products compared to those obtained via manual control. In addition, our experiments also indicated that Raman monitoring could be more efficient at enabling the chemical synthesis reaction to be completed compared to manual control. Thus, our work demonstrates the potential of Raman spectroscopy in the real-time control of chemical synthesis reactions and crystallization processes.

Sensitive quantification of acetochlor and metolachlor in water using Taguchi-optimized DLLME coupled with high-performance liquid chromatography

In this study, we developed a method that is sensitive, simple, and environmentally friendly for quantifying acetochlor and metolachlor. This method combines vortex-assisted dispersive liquid–liquid microextraction (DLLME) with high-performance liquid chromatography (HPLC). HPLC operating parameters and extraction parameters for direct and post-extraction analyses of acetochlor and metolachlor were optimized by employing the Taguchi experimental design method. The optimized HPLC parameters for acetochlor and metolachlor were 1.00 mL/min and 1.2 mL/min flow rate, 40 °C column temperature, and 70/30 (ACN/Water) and 80/20 (ACN/Water) at 210 and 230 nm wavelengths, respectively, for the direct injection method. For the DLLME procedure, 1,2-dichloroethane extraction solvent type, acetonitrile, and methanol dispersive solvent type, 400 µL and 300 µL extraction solvent volumes, and 1.0 mL dispersive solvent volume were the optimized DLLME extraction parameters, respectively. The developed and optimized methods for acetochlor and metolachlor analyses exhibited satisfactory validation results, with excellent linearity, indicated by R2 values greater than 0.99. The limit of detection (LOD) and the limit quantification (LOQ) levels of acetochlor and metolachlor were 28.96 to 31.25 µg/L, and 86.87 to 93.75 µg/L for direct injection, and 1.15 to 1.24 µg/L and 3.47 to 3.75 µg/L for post-extraction, respectively. The DLLME recovery values were within the range of 82.6–99.2 % (relative standard deviations-RSD: 4.47–10.13 %) for acetochlor and 91.1–103.4 % (4.31–7.96 %) for metolachlor. Repeatability and reproducibility results (n = 10) of direct injection and post-extraction methods for fortified acetochlor and metolachlor samples displayed very high precision lower than 2 % RSD.

Kinetic Analysis of Solvent Effect in the Photocatalytic, Aerobic Oxidation of Benzyl Alcohol over P25

Background: Photocatalysis is of particular importance in the oxidation of alcohols to aldehydes to increase the conversion of benzyl alcohol oxidation to benzaldehyde at high selectivity, which could be useful for the pharmaceutical and perfumery industries. Objective: The oxidation of benzyl alcohol over P25 was investigated in various solvents (water, benzotrifluoride, toluene and acetonitrile) Methods: The reaction was performed in an isothermal slurry batch reactor in the presence and absence of UV-light. The products were analysed using GC-FID; the deposits formed on the catalyst was analysed using TGA and FTIR. Results: In the presence of light, the reaction was very selective for the formation of benzaldehyde (e.g., 99% selectivity at 53% conversion using acetonitrile as a solvent), whereas, in the absence of light, the formation of higher molecular weight products was observed (e.g., 22% selectivity at 1.7% conversion using acetonitrile as a solvent). It was observed that the activity in the absence of oxygen was initially high, but it dropped rapidly from initially 0.4 to 0 mmol g-1 h-1 after 2-4 h (using acetonitrile as a solvent). This was attributed to the activity of the few oxidized sites present on P25. Conclusion: Acetonitrile appears to be the most effective solvent, as it seems to interact least with the catalytically active sites. The photocatalytic oxidation of benzyl alcohol over P25 does not only yield products in the solution, but also deposits on the surface. The deposits can be removed in an oxidative environment or an inert environment.

Organic Base-Promoted C-N- and C-O-Coupled Domino Cyclization Strategy: Syntheses of Oxazine-6-ones and 4-Pyrimidinols.

Oxazine-6-one and 4-pyrimidinol are two important frameworks in pharmaceutical production. Herein, we disclosed a simple, efficient, inexpensive organic base-promoted and additive-stimulated protocol for the syntheses of variably functionalized oxazine-6-ones and 4-pyrimidinols employing acetonitrile solvent under conventional heating conditions using an oil bath through C-N and C-O coupled domino steps. This simple practicable productive protocol utilizes easily producible cheap precursors, namely, benzimidates or benzamidines, with differently substituted dicyano-olefins, and it comprises step economy, robustness, and moisture insensitive conditions affording high yield that avoids the use of transition-metal catalysts, multistep with multicomponent strategy, and harsh reaction conditions involving hazardous chemicals. This method is scalable into gram-scale production with good yield.

Preparation of novel [Co(SCN)4] hybrid material: crystal structure investigation, DFT mechanistic analysis, antioxidant activity, and molecular docking study for potential inflammatory disorder control

The crystal structure of the title solvated coordination compound, [Co (SCN)4 (BtaH)2]·(BtaH)2.6(H2O), consists of discrete complexes in which the Co2+ cations are sixfold coordinated by four N-bonded thiocyanate anions and two 1-H benzotriazolium molecules to generate distorted trans-CoN6 octahedra. The discrete entities are each connected by three solvate molecules into chains via strong O—H···N hydrogen bonds. These chains are further linked by additional O—H···N, N—H···O, N—H···S, O—H···S and O—H···O hydrogen bonds into a three-dimensional network. Within this network, channels are formed that propagate along the c-axis direction and embed additional acetonitrile solvent molecules that are hydrogen-bonded to the network. In addition, density functional theory (DFT) calculations using the M06-2X/gen method were used to study the system's electronic properties. Interestingly, molecular docking and topological analyses were performed on compounds against various target anti-inflammatory receptors to investigate which targets exhibit the best binding affinities and hydrogen-bonding interactions. Done. As a result, it exhibits excellent anti-inflammatory activity, making it a suitable drug candidate for inflammatory diseases.

Study on the Catecholase Activity in the Presence of a Mn(III)-based Catalyst and Base

Background:: This work describes the oxidation of a catechol moiety to the corresponding quinone by using Mn(III)-based catalysts in the presence of an organic base. Two newly reported Mn(III)-Schiff base complexes were utilized for the oxidation of three different substrates, namely, 3,5-di tert-butyl catechol, 1,4-dihydroxy benzene and pyrocatechol, aerobically. Objective:: We intended to understand the role of a base for the above-mentioned oxidation process. Also, we were interested to monitor the progress of reaction using 1H-NMR spectroscopy and to get more insight into the mechanistic path of the reaction. Methods:: The oxidation processes were studied in open air in acetonitrile or methanol solvent. The reaction mixture containing concerned substrate, catalyst, and base were stirred in open air and 1H-NMR spectrum was recorded using the crude reaction mixture in different time intervals. Results:: Interestingly, introduction of a base in the reaction mixture, enhanced the rate to a great extent for the first two substrates. This observation may provide an idea toward the rate determining step of the process. Notably, the third substrate, pyrocatechol, could not be oxidized by any of the two cata-lysts even with a base which might emphasize monodentate binding mode of the substrate. Each of the oxidation was monitored with the help of time dependent 1H-NMR spectroscopy. Conclusion:: A mechanistic pathway has been proposed. The spectra obtained in different cases help to compare the efficiency of the catalysts with or without base. In the absence of the catalysts, triethyl-amine alone cannot complete the conversion in the stipulated time, which may establish the effective-ness of the catalysts via the base-assisted mechanism.

Photophysical Properties of (E)-1-(4-(Diethyla-mino)-2-hydroxybenzylidene)-4,4-dimethylthiosemicarbazide Compound and Its Triple Fluorescence Emission Mechanism: A Theoretical Perspective.

In view of the application prospects in biomedicine of (E)-1-(4-(diethyla-mino)-2-hydroxybenzylidene)-4,4-dimethylthiosemicarbazide (DAHTS), the behavior of excited-state dynamics and photophysical properties were studied using the density functional theory/time-dependent density functional theory method. A series of studies indicated that the intramolecular hydrogen-bond (IHB) intensity of DAHTS was enhanced after photoexcitation. This was conducive to promoting the excited-state intramolecular proton-transfer (ESIPT) process. Combining the analysis of the IHB and hole-electron, it revealed that the molecule underwent both the ESIPT process and the twisted charge-transfer (TICT) process. Relying on exploration of the potential energy surface, it was proposed that the different competitive mechanisms between the ESIPT and TICT processes were regulated by solvent polarity. In acetonitrile (ACN) solvent, the ESIPT process occurred first, and the TICT process occurred later. In contrast, in the CYH solvent, the molecule first underwent the TICT process and then the ESIPT process. Furthermore, we raised the possibility that the TICT behavior was the cause of weak fluorescence emission for the DAHTS in CYH and ACN solvents. By the dimer correlation analysis, the corresponding components of triple fluorescence emission were clearly assigned, corresponding to the monomer, dimer, and ESIPT isomer in turn. Our work precisely elucidated the photophysical mechanism of DAHTS and the attribution of the triple fluorescence emission components, which provided valuable guidance for the development and regulation of bioactive fluorescence probes with multiband and multicolor emission characteristics.

A theoretical investigation to understand the difference in reactivities of secondary and tertiary propargylic alcohols with 1,3,5‐trimethoxybenzene in presence of Brnøsted acid

AbstractThe work presented here establishes the experimental findings of the reaction between secondary/tertiary propargylic alcohol (PA) and 1,3,5‐trimethoxybenzene (TMB) in the presence of acetonitrile solvent (MeCN) based on theoretical calculations. When secondary PA reacts, the reaction goes via SN2 pathway, where the reaction barrier is about 14.32 kcal/mol. On the other hand, tertiary PA reacts with TMB via SN2′ and SN1′ pathway, and the corresponding reaction barriers are 17.59 and 17.86 kcal/mol. Other possible pathways, namely, SN1, SN1′, etc. for secondary PA, and SN2, SN1 pathways for tertiary PA are also investigated and the associated barrier heights are found higher. Rates of those reactions are also calculated considering the rate‐determining steps only. Reaction of secondary PA with TMB is found to be much faster than the reaction of tertiary PA and the results are in accordance with the experimental findings.

Thermodynamic and Kinetic Activity Descriptors for the Catalytic Hydrogenation of Ketones.

Activity descriptors are a powerful tool for the design of catalysts that can efficiently utilize H2 with minimal energy losses. In this study, we develop the use of hydricity and H- self-exchange rates as thermodynamic and kinetic descriptors for the hydrogenation of ketones by molecular catalysts. Two complexes with known hydricity, HRh(dmpe)2 and HCo(dmpe)2, were investigated for the catalytic hydrogenation of ketones under mild conditions (1.5 atm and 25 °C). The rhodium catalyst proved to be an efficient catalyst for a wide range of ketones, whereas the cobalt catalyst could only hydrogenate electron-deficient ketones. Using a combination of experiment and electronic structure theory, thermodynamic hydricity values were established for 46 alkoxide/ketone pairs in both acetonitrile and tetrahydrofuran solvents. Through comparison of the hydricities of the catalysts and substrates, it was determined that catalysis was observed only for catalyst/ketone pairs with an exergonic H- transfer step. Mechanistic studies revealed that H- transfer was the rate-limiting step for catalysis, allowing for the experimental and computation construction of linear free-energy relationships (LFERs) for H- transfer. Further analysis revealed that the LFERs could be reproduced using Marcus theory, in which the H- self-exchange rates for the HRh/Rh+ and ketone/alkoxide pairs were used to predict the experimentally measured catalytic barriers within 2 kcal mol-1. These studies significantly expand the scope of catalytic reactions that can be analyzed with a thermodynamic hydricity descriptor and firmly establish Marcus theory as a valid approach to develop kinetic descriptors for designing catalysts for H- transfer reactions.

Galvinol as ratiometric naked-eye colorimetric moisture sensor: Synthesis process development, applications and mechanistic studies

Moisture detection through a simple colorimetric approach using molecular materials has been a cost-effective and user-friendly technology of choice as high moisture and humidity conditions lead to serious issues across various fields. However, the poor availability of such efficient molecular systems is a serious concern, and hence the need is quite evident. In this regard, the galvinol (GALH) molecule has been explored as a highly responsive colorimetric moisture-sensing in liquid and gaseous systems. Notably, it has been synthesized in a multigram scale via an unexplored demethylative C-C coupling of butylated hydroxyl toluene (BHT). The deprotonated form of GALH (GAL-) has been investigated as a reversible colorimetric moisture sensing platform with limits of detection (LOD) for water (H2O) in acetonitrile and tetrahydrofuran solvents as 0.0022 and 0.0031% v/v, respectively. The moisture sensing mechanism is based upon the competitive ion pairing of GALH with tetra-n-butylammonium fluoride and H2O during the protonation/deprotonation process. The developed moisture sensing probe has shown its universal applicability during the fabrication of polystyrene resin anchored solid medium device for relative humidity detection, color indicating moisture absorbing silica gel preparation, paper strip-based moisture detection in organic solvents and soil as real sample analysis, moisture erasable inkjet-printing and inkless writing.

Synthesis of Molecularly Imprinted Polymers with Magnetite Cores for Ibuprofen Adsorption

Ibuprofen (IBP) is a pollutant that is widely found in aquatic environments due to pharmaceutical waste and the metabolic results of humans who consume the drug. These compounds can cause damage to aquatic ecosystems, genotoxicity, and aquatic toxicity and are harmful to human health. This study aims to selectively adsorb IBP using magnetic molecularly imprinted polymers (MMIPs) synthesized from ibuprofen (IBP) as a template molecule, methacrylic acid (MAA) as a functional monomer, and divinylbenzene (DVB) as a crosslinker with a mole ratio of 1:4:20 in acetonitrile porogen solvent using a bulk polymerization method. Fe3O4 nanoparticles and MMIPs were characterized using X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR), and Scanning Electron Microscope (SEM). IBP adsorption reached optimum conditions at pH 3 with a contact time of 90 minutes and a mass of 25 mg of adsorbent. The adsorption performance of MMIPs for IBP was evaluated by adsorption isotherms and adsorption kinetics. Adsorption of IBP by MMIPs followed the Langmuir adsorption isotherm model with an adsorption capacity of 227.24 mg/g. Kinetic studies showed that the adsorption process followed a pseudo-second-order adsorption kinetic model. MMIPs can adsorb IBP selectively even in the presence of interfering compounds, are easily separated from the solution, and can be used repeatedly with good adsorption ability. Hence, it is efficient and promising for removing IBP from aqueous media.

Study on the adsorption of 2,4-dichlorophenoxyacetic acid on silver doped carbon nanotube using tight-binding quantum chemical method

The GFN2-xTB tight-binding quantum chemical method was utilized to investigate the adsorption ability of 2,4-dichlorophenoxylacetic acid (2,4-D) on pristine single-walled carbon nanotube (CNT) and silver-doped carbon nanotube (Ag-CNT). The effects of solvents (water, methanol, and acetonitrile) on the adsorption process were evaluated via the linear Poisson-Boltzmann analysis algorithm. The analysis of ionization energy, electron affinity, and global electrophilic indexes indicates that Ag doping alters the electronic properties of CNT through the formation of Ag-C chemical bonds. While the adsorption process of 2,4-D on pristine CNT is primarily of a physical nature, the adsorption on Ag-CNT involves chemical adsorption facilitated by the formation of Ag-Cl and Ag-O bonds. Contributions from non-covalent interactions (such as π-π stacking, van der Waals interactions, etc.) were analysed and clarified through the computation of the reduced density gradient. Our findings suggest that Ag-CNT has significant potential as a material for the adsorption and remediation of 2,4-D.

Imprinting-based smart syringe: A fast, efficient, and selective approach for extraction of methyl gallate from Caesalpinia pulcherrima extract

A simple, facile, quick, highly selective, and efficient extraction protocol for a medicinal compound methyl gallate (MG) is developed for the first time using molecularly imprinted-based solid phase extraction (MISPE). Density functional theory (DFT) was employed to calculate the binding energies of the complex of MG with the functional monomer in the gas and in the implicit solvent to evaluate the best combination of the functional monomer, crosslinker, and porogen for MG. Decisively, the synthesis of a molecularly imprinted polymer (MIP) and its respective non-imprinted polymer (NIP) was conducted using methacrylamide (MAAm) as a functional monomer, trimethylolpropane trimethacrylate (TRIM) as a crosslinker, and methanol as a porogen. The polymers were characterized by SEM, FT-IR, BET, and TGA, while the adsorption properties of MG-MIP/NIP were evaluated by batch rebinding experiments. Theoretical modeling was done by Langmuir, Freundlich, Scatchard analysis, LF-isotherm, and kinetic models. The MG-MIP appeared to have a higher binding capacity towards MG compared to the corresponding NIP: 57.6 mg/g compared to only 17.6 mg/g rendering an imprinting factor 3.3. Moreover, in competitive recognition studies, the synthesized MG-MIP showed good selectivity towards MG compared to its structural analogs, confirming the presence of MG-specific imprinting sites. In competitive recognition tests and real-sample analysis, HPLC was used to determine the concentration of MG and the analogous compounds. Furthermore, the volume and elution times of the washing solvent (DI water) and elution solvent (acetonitrile) were optimized. Finally, MG-MISPE frits were successfully designed for selective enrichment of MG from Caesalpinia pulcherrima methanolic extract using a syringe, PTFE membrane, and MG-MIPs. Hence, MG-MISPE is a promising alternative of traditional extraction methods for selective extraction and enrichment of MG from complex plant matrices. The approach has potential to be applied to any compound of interest.

IgG glycopeptide enrichment using hydrophilic interaction chromatography-based solid-phase extraction on anaminopropyl column.

The sample preparation step is pivotal in glycoproteomic analysis. An effective approach in glycoprotein sample preparation involves enriching glycopeptides by solid-phase extraction (SPE) using polar stationary phases in hydrophilic interaction liquid chromatography (HILIC) mode. The aim of this work is to show how different experimental conditions influence the enrichment efficiency of glycopeptides from human immunoglobulin G (IgG) on an aminopropyl-modified SPE column. Different compositions of the elution solvent (acetonitrile, methanol, and isopropanol), along with varying concentrations of elution solvent acidifiers (formic and acetic acid), and different concentrations of acetonitrile for the conditioning and washing solvents (65%, 75%, and 85% acetonitrile) were tested to observe their effects on the glycopeptide enrichment process. Isopropanol proved less effective in enriching glycopeptides, while acetonitrile was the most efficient, with methanol in between. Higher formic acid concentrations in the elution solvent weakened the ionic interactions, particularly with sialylated glycopeptides. Substituting formic acid with acetic acid led to earlier elution of more glycopeptides. The acetonitrile concentration in conditioning and washing solutions played a key role; at 65% acetonitrile, glycopeptides were not retained on the SPE column and were detected in the flow-through fraction. Ultimately, it was proven that the enrichment method was applicable to human plasma samples, resulting in a significant decrease in the abundances of non-glycosylated peptides. To the best of our knowledge, this study represents the first systematic investigation into the impact of the mobile phase on glycopeptide enrichment using an aminopropyl-modified SPE column in HILIC mode. This study demonstrates the substantial impact of even minor variations in experimental conditions, which havenot yet beenconsidered in the literature, on SPE-HILIC glycopeptide enrichment. Consequently, meticulous optimization of these conditions is imperative to enhance the specificity and selectivity of glycoproteomic analysis, ensuring accurate and reliable quantification.

Understanding the Interplay of the Brønsted Acidity of Catalyst Ancillary Groups and the Solution Components in Iron-porphyrin-Mediated Carbon Dioxide Reduction.

The rapid and efficient conversion of carbon dioxide (CO2) to carbon monoxide (CO) is an ongoing challenge. Catalysts based on iron-porphyrin cores have emerged as excellent electrochemical mediators of the two proton + two electron reduction of CO2 to CO, and many of the design features that promote function are known. Of those design features, the incorporation of Brønsted acids in the second coordination sphere of the iron ion has a significant impact on catalyst turnover kinetics. The Brønsted acids are often in the form of hydroxyphenyl groups. Herein, we explore how the acidity of an ancillary 2-hydroxyphenyl group affects the performance of CO2 reduction electrocatalysts. A series of meso-5,10,15,20-tetraaryl porphyrins were prepared where only the functional group at the 5-meso position has an ionizable proton. A series of cyclic voltammetry (CV) experiments reveal that the complex with -OMe positioned para to the ionizable -OH shows the largest CO2 reduction rate constants in acetonitrile solvent. This is the least acidic -OH of the compounds surveyed. The turnover frequency of the -OMe derivative can be further improved with the addition of 4-trifluoromethylphenol to the solution. In contrast, the iron-porphyrin complex with -CF3 positioned opposite the ionizable -OH shows the smallest CO2 reduction rate constants, and its turnover frequency is less enhanced with the addition of phenols to the reaction solutions. The origin of this effect is rationalized based on kinetic isotope effect experiments and density functional calculations. We conclude that catalysts with weaker internal acids coupled with stronger external acid additives provide superior CO2 reduction kinetics.

High-performance liquid chromatographic enantioseparation of azole analogs of monoterpene lactones and amides focusing on the separation characteristics of polysaccharide-based chiral stationary phases

High-performance liquid chromatography-based enantioseparation of newly prepared azole analogs of monoterpene lactones and amides was studied. Effects of additives and mobile phase composition were evaluated both in normal and polar organic modes. Applying amylose tris-(3,5-dimethylphenylcarbamate) selector in normal and polar organic modes acid and base additives were found to affect the peak profiles, without significantly influencing the enantiorecognition ability of the studied selector. In most cases, differences observed in retention times and enantioselectivities were lower than 10 and 20 % under normal phase and polar organic conditions, respectively. Under normal phase conditions decreased retention was observed for all the studied analytes with increased eluent polarity. Interestingly, enantioselectivity was only slightly (<10 %) influenced by the variation in the n-hexane/2-propanol ratio between 80/20 and 20/80 v/v. In polar organic mode, five different neat solvents (acetonitrile, methanol, ethanol, 1-propanol, and 2-propanol) were tested, and the best results were obtained with acetonitrile and ethanol in the case of Lux Amylose-1 column with enantioresolutions most often above 2. Based on results obtained with amylose and cellulose-based columns the amylose tris-(3,5-dimethylphenylcarbamate) selector is found to offer a superior performance both in normal and polar organic modes. When evaluating the possible effects of the selector immobilization, no striking differences were found in the normal phase. Usually, enantioselectivities and resolutions were higher (10–20 %), while retention factors of the first peaks were lower (20–30 %), on the coated-type column. In contrast, in polar organic mode, the retention characteristics and enantiorecognition ability of the coated and immobilized selectors were heavily affected by the nature of the polar solvent.Special attention has been paid to the history-dependent behavior of polysaccharide-based selectors. A confidence interval-based evaluation is suggested to help comparison of the histereticity observed in different systems. Several examples are shown to confirm that the recently discovered hysteresis is a common characteristic of polysaccharide-based selectors.

An efficient imine-linkage colorimetric probe for specific recognition of saringas surrogate, diethylchlorophosphate

The severe toxicity and easy availability of nerve agents have caused an increase in the need to develop effective methods for identifying these lethal substances. Among the traditional platforms employed for this kind of purpose, chromophore-based chemosensors have garnered a significant amount of attention. In this study, we have designed, prepared, and characterized (N1E,N4E)-N1,N4-bis((Z)-3-(4-(dimethylamino)phenyl) allylidene)benzene-1,4-diamine, BDPA, a simple chromogenic probe of symmetrical diimine, having the extreme capability to sensing diethylchlorophosphate (DCP), the mimic of chemical warfare agent sarin not only in solution but also in solid and vapor phases with highly selective and sensitive manner. In the presence of DCP, a remarkable color change from light yellow to blue is observed in pure acetonitrile solvent and also shows pink color in 10 % acetonitrile–water by the naked eye, comes back to its former state after the introduction of triethylamine (TEA) which is found to be five times recyclability by alternately adding DCP and TEA. The detection limit of BDPA with DCP has been estimated in the nanomolar range, and also, response time towards sarin surrogate DCP is withina few minutes (∼5–6 min.).To determine its practical usability, we have developed a portable test kit that uses paper strips to assess the capability of BDPA for in-situ recognition and measurement of DCP. A dipstick method has also been executed to recognize gaseous DCP within the stores of analogous hazardous analytes to prove the effectiveness of the sensor, BDPA. A smartphone-based readout novel technique, i.e., RGB analysis, has provided an innovative platform for the instant, on-site, visual identification and measurement of DCP in remote areas. The current work presented an incredible probe and method for conveniently and instantly detecting and quantifying sarin gas mimics in actual dangerous circumstances.

Novel electrolyte assisted ultralow-temperature zinc battery

Secondary battery is an indispensable component in energy storage as it can uninterruptedly store the energy and release it when being required. Among them, zinc (Zn) rechargeable battery gains much attention due to its cost advantage. However, poor climate adaptation much weaken the competitiveness, and temperature-induced deterioration can be mainly blamed on the slow reaction-kinetics of Zn anode under low temperature. Under this scenario, an anti-freezing electrolyte with Zinc (II)Bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) salt and ternary solvents of acetonitrile (AN), methyl acetate (MA) and dichloromethane (DCM) is proposed. It successfully broadens the working temperature of Zn secondary battery to − 90 °C. The elaborately regulated solvation can ensure smooth ion-transfer in liquid zone, more importantly, it expedites the desolvation without much affecting the interface transportation. With the optimized electrolyte configuration, reversible Zn plating/stripping at ultra-low temperature has been realized. The Zn|polytriphenylamine (PTPAn) battery thus can reserve 70 % capacity at − 80 °C, and present extremely stable cycling and impressive rate capability at − 80 °C and − 60 °C. The results well address the kinetics issues encountered in the low-temperature Zn secondary battery, and reveals that only with appropriate solvation, the high ion-permeability of the interface as well as easy de-solvation can be guaranteed. The work provides a guideline for designing advanced electrolyte, and supplies a reliable and effective strategy for the all-weather electrochemical energy storage.