Butyl Acetate Research Articles

The Odorant-Binding Protein 1 Mediates the Foraging Behavior of Grapholita molesta Larvae.

Since eggs are laid directly on fruit skin, it is typically believed that food odor has little impact on the foraging of Grapholita molesta larvae. It is crucial to note that larvae that hatch on twigs and leaves could need some sort of identification system when foraging. Here, 22 GmolOBP genes were identified from the G. molesta larval transcriptome via the comparison of conserved domain and homology in the protein level. GmolOBP1 had strong affinities for important pear-fruit volatiles, which caused larvae strong behavioral responses. However, after GmolOBP1 silencing, the larvae lost their attraction to methyl salicylate, α-farnesene, butyl acetate, ethyl butanoate, and ethyl hexanoate, and the effects of larvae seeking various pears were significantly reduced. Consequently, GmolOBP1 was required for the reception of pear volatiles and was involved in mediating how G. molesta larvae foraged. Our research revealed the GmolOBP1 foraging signal recognition mechanism as well as potential molecular targets for field pest management.

2,3-Dichloropyridine solubility in 14 pure solvents: Determination, correlation, Hansen solubility parameter, solvent effect and thermodynamic analysis

The solid–liquid equilibrium data of 2,3-dichloropyridine(23DCP) in 14 pure solvents were measured making use of the laser dynamic monitoring at 278.15/283.15/288.15 K − 313.15 K with 0.1 MPa. The findings of this study showed that the solubility increase of 23DCP in 14 pure solvents had a positive relation with temperature, and the solubility order was 1,4-dioxane > dichloromethane > n-butyl acetate > ethyl acetate > methyl acetate > acetonitrile > n-butanol > isobutyl alcohol > n-propanol > isopropanol > ethanol > cyclohexane > methanol > n-hexane. The solubility data of 23DCP was operated by seven models (Van't Hoff, modified Apelblat, λh, Yaws, NRTL, NRTL-SAC, Wilson) to correlate. And the average ARD values were 1.684 %,1.058 %, 1.031 %, 0.905 %, 0.937 %, 1.012 %, 2.062 % and the average 103RMSD values were 1.978, 1.396, 1.542, 1.221, 1.758, 1.658 and 1.883, respectively. In addition, Hansen solubility parameters were well evaluated to appraise the miscibility of 23DCP in 14 pure solvents. And the interactions between molecules were studied by means of molecular electrostatic potential surface, Hirshfeld surface analysis and density functional theory calculation. Finally, according to Van't Hoff equation, ΔsolG°, ΔsolH° and ΔsolS° of 23DCP in 14 pure solvents were got. ΔsolH° and ΔsolS° were bigger than zero, representing that this was a dissolution process of endothermic and entropy increase.

Photochromic performance optimization of polyurethane microcapsules by interfacial polymerization method

AbstractSpiropyran photochromic materials have been widely studied in military camouflage, optical data storage, information encryption, and fashion ornaments. The non‐photochromism and low endurance of solid spiropyran make the challenges of their application. Photochromic microcapsules with a butyl acetate solution of spiropyran as core and polyurethane as shell are synthesized via interfacial polymerization. The optimized polyurethane photochromic microcapsules are prepared with a Tween 20 concentration of 4 wt%, core–shell ratio of 16:5, and spiropyran concentration of 0.40 wt%. Polyurethane photochromic microcapsules with a mean particle diameter of 0.33 μm are obtained. The morphology shows smooth spheres, and the core–shell structure is observed. Butyl acetate in the microcapsule core does not evaporate at a temperature lower than 218.01°C as the microcapsule shell insulates heat. The polyurethane photochromic microcapsules are mixed with adhesive, thickener, and water into a paste and screen‐printed on cotton fabric. The printed fabric shows the ΔE of 17.56, 11.93, and 6.96 after 80s irradiation with the xenon lamp intensity of 102, 68, and 34 mW cm−2. The light stability of the photochromic fabric is excellent as ΔE decreases about 8.28% after 20 cycles of UV‐Vis irradiation.

Design and analysis of arc-shaped single core photonic crystal fiber sensor based on surface plasmon resonance

The selection of a suitable plasmonic material is crucial for achieving high-performance photonic crystal fiber-based surface plasmon resonance (PCF-SPR) sensors. However, most numerical investigations have been limited to PCF-SPR sensors with conventional circularly coated plasmonic metals due to their availability and rigid properties. In this work, a single-core arc-shaped PCF is designed and studied with sensing ingredients coated outside the fiber. The simulation and numerical analyses are performed using the full-vector finite element method to examine the effects of using gold as an active metal and also the deposition of Ta2O5 on gold. The results show that the arc-shaped sensor with gold film can obtain the maximum wavelength interrogation sensitivity (WIS) of 9500 nm/RIU within the refractive index (RI) range of 1.25–1.39 while the maximum amplitude interrogation sensitivity (AIS) reaches 579.26 RIU−1 at 1.39 and resolution is 1.05 × 10−5. However, depositing Ta2O5 on the gold gives an improved maximum WIS and AIS of 22,000 nm/RIU and 1209.21 RIU−1, respectively. With the coating of Ta2O5, the resolution improves to 4.55 × 10−6, making the proposed sensor design undoubtedly effective in detecting food chemicals such as butyl acetate and hydrocarbons along with different bio-analyte samples with a wide range of RI.

Green catalysis for the production of n-butyl acetate over phosphotungstic acid-encapsulated metal-organic framework UiO-67 catalyst: Catalyst preparation, characterization and reaction kinetics

In the present study, a composite of Keggin-type phosphotungstic acid encapsulated in sized-matched metal-organic framework UiO-67 (HPW@UiO-67) was successfully fabricated via a facile hydrothermal synthesis method and utilized for the preparation of n-butyl acetate. The as-synthesized composite catalyst was comprehensively characterized using FT-IR, PXRD, ICP-OES, N2 adsorption-desorption, SEM, TEM, NH3-TPD, TGA-DTG and XPS techniques. The characterization results confirmed that HPW was successfully immobilized in metal-organic framework without changing the structure of UiO-67. The asprepared HPW@UiO-67 catalyst exhibited higher esterification activity compared to the UiO-67 catalyst due to its suitable surface area and total volume, high dispersion of phosphotungstic acid and high total acidity. The kinetic study indicated that the process followed the second-order kinetic with the activation energy Ea = 53.1 kJ/mol. The catalyst exhibited good recovery and catalytic performance in the reuse study, maintaining the conversion of acetic acid above 63.1% after four reaction cycles. Moreover, the reaction mechanism for the synthesis of n-butyl acetate via esterification over HPW@UiO-67 was proposed.

Catalytic Oxidation Process and Thermal Characteristics of Toluene and Butyl Acetate Vapor in an Oven

Catalytic Oxidation Process and Thermal Characteristics of Toluene and Butyl Acetate Vapor in an Oven

Solubility of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in sustainable and green solvents: Effect of HV content and comparison between experimental results and theoretical prediction

For the first time, a quantitative analysis of the solubility of poly-3hydroxybutyrrate-co-3hydroxyvalerate (PHBV) in green solvents is proposed. The solubility of two commercial co-polymers, with hydroxyvalerate (HV) contents of 8 %mol and 12 %mol, in 1,3-dioxolane, dimethyl carbonate and butyl acetate was experimentally determined using chloroform as the benchmark and water as the control. The results showed a direct correlation between solubility and temperature, with a maximum at the boiling point of the solvent. For PHBV with an HV content of 8 %mol, solubilities of 265 mg mL−1 for 1,3-dioxolane and dimethyl carbonate and 274 mg mL−1 for butyl acetate were measured; for PHBV with an HV content of 12 %mol, solubilities of 225 mg mL−1, 197 mg mL−1 and 137 mg mL−1 for 1,3-dioxolane, dimethyl carbonate and butyl acetate were measured, respectively. Following Hansen's theory, the PHBV solubility sphere was defined to predict the solubility of the co-polymers in solvents qualitatively. The validation of the sphere was performed by the experimental results herein obtained.

The Therapeutic Role of Olea europaea in Alcohol Dependence Base in Network Pharmacology Analysis

Alcohol dependence is a state of alcohol becoming a vital part of the life of a person who consumes it; when discontinued, it can lead to a wide range of physical and mental health disorders as well as a decrease in life productivity in people with alcohol dependence. Olea Europaea (OE) is a plant capable of treating alcohol dependence. The method used in silico-based pharmacological grid analysis to determine the ability of the OE compound to treat alcohol dependence. EO compound data is obtained from the KnapSack database, absorption, distribution, metabolism, and excretion (ADME) screening using SwissADME, target protein prediction using SwissTargetPrediction, Gene cards, venny, pharmacological grid analysis with String-DB, visualization with Cytoscape 3.10.0. Results are obtained from 63 OE compounds, and 17 have ADME criteria matching the drug compounder (Drug Likeness/DL). The pathways that correlate with therapy are dopamine receptors, dopamine transporter, serotonin receptor, gamma-aminobutyric acid receptor, and toll-like receptors for known therapeutic target proteins: OPRM1, DRD2, ALDH2, ADH1B, ADH1A, ADH1C, ADH4, ADH7, SLC6A3, CNR1, POMC, ARRB2, and NCS1. Compounds associated with alcohol dependency therapy include Hexanal, Nonadienal, Octanal, 3-Hexenal, 3-Methyl-butanal, Methyl nominate, Cinchonidine, cinchonine, (9S)-10,11-Dihydrocinchonan-9-ol, Oleuropeic acid, Butyl acetate, cis-3-hexenyl acetate, and (S)-2,3-Epoxysqualene. Based on the findings, OE is a potential drug candidate for alcohol dependence.

Adsorption modeling for contaminant removal in plastic dissolution recycling: Investigating an amino ketone-based red dye

The widespread inclusion of additives in plastics has posed a significant challenge to increasing global plastic recycling rates. This study explores the potential of adsorption in non-aqueous environment as a novel approach for plastic waste dissolution recycling. Activated charcoal was selected as the adsorbent for the removal of Solvent Red 135, a commonly used amino ketone-based dye, from polystyrene (PS) solutions. Three solvents, namely o-xylene, limonene, and butyl acetate, were investigated. Adsorption experiments were conducted at 293 K, and the results were analyzed using both classical and statistical physics models. The activated charcoal exhibited the highest single component adsorption capacity for the dye when butyl acetate was used as the solvent, while it showed negligible adsorption for PS in all three solvents. When dealing with mixtures of the dye and 1.0 wt% PS in butyl acetate, a removal efficiency of 99% was achieved at an adsorbent dose of 2.0 g L-1. However, when the PS concentration in the solvent increased to 10 wt%, the required adsorbent dose rose to 3.3 g L-1. Modeling results indicated that monolayer adsorption occurred via a multi-molecular adsorption mechanism, with an approximate adsorbed dye molecule count of 1.5 per adsorption site. The adsorption energy for all three solvents ranged between 0 and 40 kJ mol-1, indicating that the adsorption process is predominantly driven by physical forces and is an endothermic process. This study presents a foundational assessment of adsorption as an effective solvent-based technique for the removal of additives in plastic recycling.

Effects of pear fruit‐derived volatiles and their concentrations on the responses of oriental fruit moths

AbstractGrapholita molesta (Busck) is an important pest of pear trees. Numerous esters accumulate consistently in mature pear fruits. However, little is known about the effects of single esters from pear fruits at different concentrations on the responses of male and female G. molesta. In this study, the responses of virgin males, virgin females, and gravid females to five esters (3‐methylbutyl acetate, ethyl hexanoate, ethyl butanoate, butyl acetate, and hexyl acetate) of pear fruits at three dosage levels (1, 5 and 10 μg/μL) were investigated using electroantennography (EAG), wind tunnel experiments, and field tests. Our results showed that ethyl butanoate (5 μg/μL) elicited higher EAG responses in virgin females and males than a mixture of all five volatiles, and elicited an equal EAG response to that for the mixture in gravid females, with all responses to ethyl butanoate and the mixture being higher than the response to hexane alone. For upwind flight, ethyl butanoate (5 μg/μL) excited equal moth flight–location behavior in virgin and gravid females to that for the mixture, which were both higher than the response to hexane. For close flight, ethyl hexanoate (5 μg/μL) and 3‐methylbutyl acetate (10 μg/μL) appeared to be the activating compounds, eliciting equal responses from virgin females to that of the mixture, and higher responses of gravid females to that of the mixture, both of which were higher than the responses to hexane. Upwind and close flight responses of virgin males were lower than those of virgin and gravid females. In field trials, we verified that traps baited with ethyl butanoate (5 μg/μL) captured more moths than the other esters. Therefore, from the esters and concentrations tested, we recommend ethyl butanoate (5 μg/μL) for potential use as an attractant for G. molesta in orchards.

Separation of 1-methoxy-2-propanol and water by organic solvent extraction based on quantum chemistry calculation and liquid-liquid equilibrium experiment

1-Methoxy-2-propanol (PM) is extensively utilized in various industries, including coatings and semiconductor applications, owing to its low toxicity and affordability. However, PM + water mixture was an azeotrope with lowest boiling point, which presents a challenge in separating azeotropic mixture for industrial production. In this study, selectivity coefficient (Scal) and extractant loss (SL) were calculated using the open-source COSMO-SAC model by evaluating its activity coefficients at infinite dilution. Then, four extractants, butyl propionate, butyl acetate, 4-methyl-2-pentanone (MIBK) and isobutyl alcohol, were selected and verified. The ternary liquid–liquid equilibrium (LLE) data measurement for water + PM + butyl propionate/ butyl acetate/MIBK/ isobutyl alcohol systems were achieved at 298.15 K and 101.3 kPa. In addition, distribution coefficient (D) and selectivity coefficient (S) were calculated by the achieved data and used as indexes to further judge the performance of the extractants. Meanwhile, the widely adopted NRTL activity coefficient model was applied to regress LLE data, the corresponding root mean square deviation (RMSD) was less than 0.008. Accuracy of the regressed binary interaction parameters were evaluated through the Gibbs energy topology analysis. Besides, the possible extraction ability was investigated and confirmed at the micro level, of which the electrostatic potential (ESP), H-bond length, complexes’ interaction energy were explored. Further, the radial distribution function (RDF) was achieved by molecular dynamics (MD) simulation to further explain its interactions. This study can provide new theoretical guidance for organic extractants selection,then used for the separation of PM from azeotropic mixtures.

Green synthesis of metal-organic framework materials MOF-199 and its adsorption of organic solvents gas

This study synthesized the copper benzene-1,3,5-tricarboxylate metal-organic framework (Cu-BTC) by the hydrothermal method in mixed solvent water/ethanol/PEG. The formed MOF-199 material has a uniform, sharp, octahedral crystal morphology with a 5 ÷ 8 µm size. The surface area of MOF-199 with the BET model is 1.360,76 m2/g. This material can adsorb volatile organic compounds with high capacity. The saturation adsorption capacity of MOF-199 with ethanol, acetone, benzene, toluene, and butyl acetate was 99,50; 86,80; 91,00; 79,00; 104,50 mg/g, respectively. The regenerative capacity of the material also showed that the material was resistant to volatile organic solvents when used 7 times in a row, only decreased under 10%.

Removal of butyl acetate in an industrial ef uent through a physicochemical treatment

Butyl acetate is an organic compound widely used in industry, focu- sing on industrial paint waste ef uents. Exposure to this pollutant at an average of 925 ppm can cause dizziness, drowsiness, respiratory tract irritation, and central nervous system suppression. That is why it seeks to minimize the risk associated with this contaminant through treatment alternatives. The characterization of the sample yielded the detection of the following contaminants: methyl ester, 1-butanol, 1-4 dioxane, butyl ester, 1-chlorobutane. The objective of this work was the design and development of combined treatments for the removal of butyl acetate in industrial waste ef uents. For this, a physicoche- mical treatment coupled to an advanced oxidation process (PAO) was implemented. The results showed that the coupled treatments are ef - cient for the removal of butyl acetate, methyl ester, 1-chlorobutane and 1-butanol, while for 1-4 dioxane it was reduced by approximate- ly 83%. The study was complemented with the evaluation of the fo- llowing parameters, resulting in a decrease in electrical conductivity of 99.5%, total suspended solids of 74%, color of 93%, turbidity of 55% and COD of 73%.

Oxidation characteristics and hazardous of α-pinene, β-pinene and turpentine

α-Pinene, β-pinene and turpentine are renewable resources that are widely used in fine chemicals, fuels and other applications, and the safety of their production, transport and use should be considered. In this work, the characteristics and hazardous of the oxidation process of α-pinene, β-pinene and turpentine were investigated by using a novel mini closed pressure vessel testing system (MCPVT). The oxidation products were resolved by gas chromatography-mass spectrometry (GC–MS). The results showed that α-pinene, β-pinene and turpentine were stable under nitrogen atmosphere and very active chemically under oxygen atmosphere. The activation energies (Ea) of α-pinene, β-pinene and turpentine were calculated to be 78.87, 109.69 and 98.82 kJ/mol, respectively, using pressure–time (P-t) curves. So, the reaction activity sequence was α-pinene > turpentine > β-pinene. The peroxide concentrations of α-pinene (363 K), β-pinene (358 K) and turpentine (363 K) could reach 81.94, 84.70 and 75.76 mmol/kg, respectively, at relatively low temperatures. 0.6 g of α-pinene exploded at a system temperature of 369 K and an oxygen pressure of 1.23 MPa. 0.6 g of β-pinene also exploded at a system temperature of 373 K and an oxygen pressure of 1.27 MPa. 0.4 g of turpentine experienced thermal runaway at a system temperature of 384 K and an oxygen pressure of 0.81 MPa. The major oxidation products of α-pinene are α-campholenaldehyde, laevo-pinocarveol, verbenol, verbenone, bicyclo (3.1.1)heptane-2, 3-diol, 2, 6, 6-trimethyl, 2-cyclohexen-1-ol, 2-methyl-5-(1-methylethenyl)-, (1R,5R)-rel-, cyclobutaneacetic acid, 3-acetyl-2, 2-dimethyl, myrtenol and myrtenal. The major thermal runaway products are water, ethanol, acetone, acetic acid, 2-pentanone, propyl acetate, toluene, cymene and methylacetophenone. The major oxidation products of β-pinene are nopinone, laevo-pinocarveol, pinocarvone, myrtenol, myrtenal and perillyl alcohol. The major thermal runaway products are water, ethanol, acetone, n-ethyl propanoate, toluene, butyl acetate, cymene, apocamphor, nopinone, bornyl formate, methylacetophenone and dihydronopol. The oxidation products and thermal runaway products of pinene were significantly different. Possible reaction pathways for α-pinene and β-pinene are proposed.

Hybrid extraction distillation for downstream purification of 2, 3-butanediol, and ethanol from fermentation broth

2,3-Butanediol is a valuable specialty chemical used in various industries and as a fuel additive. The bio-based production is significant as it's renewable and not reliant on petroleum feedstock. However, purifying 2,3-butanediol from complex fermentation broth is challenging. An integrated hybrid extraction distillation (HED) approach was developed to address this. The process was optimized using butyl acetate solvent, resulting in a maximum recovery efficiency of 91.39 % and purity of 99.99 % for 2,3-butanediol. Simultaneously, 92.22 % ethanol was recovered with 99.11 % purity. The solvent, 96 % of which was recovered, had a purity of 98.38 % and could be successfully recycled. This promising process has the potential for scaling up on a pilot scale.

Innovative Solid Slippery Coating: Uniting Mechanical Durability, Optical Transparency, Anti-Icing, and Anti-Graffiti Traits.

Slippery coatings, such as the slippery liquid-infused porous surface (SLIPS), have gained significant attention for their potential applications in anti-icing and anti-fouling. However, they lack durability when subjected to mechanical impact. In this study, we have developed a robust slippery coating by blending polyurethane acrylate (PUA) with methyltriethoxysilane (MTES) and perfluoropolyether (PFPE) in the solvent of butyl acetate. The resulting mixture is homogeneous and allows for uniform coating on various substrates using a drop coating process followed by drying at 160 °C for 3 h. The cured coating exhibits excellent water repellency (contact angle of ~108° and sliding angle of ~8°), high transparency (average visible transmittance of ~90%), exceptional adherence to the substrate (5B rating according to ASTMD 3359), and remarkable hardness (4H on the pencil hardness scale). Moreover, the coating is quite flexible and can be folded without affecting its wettability. The robustness of the coating is evident in its ability to maintain a sliding angle below 25° even when subjected to abrasion, water jetting, high temperature, and UV irradiation. Due to its excellent nonwetting properties, the coating can be employed in anti-icing, anti-graffiti, and anti-sticking applications. It effectively reduces ice adhesion on aluminum substrates from approximately 217 kPa to 12 kPa. Even after 20 cycles of icing and de-icing, there is only a slight increase in ice adhesion, stabilizing at 40 kPa. The coating can resist graffiti for up to 400 cycles of writing with an oily marker pen and erasing with a tissue. Additionally, the coating allows for easy removal of 3M tape thereon without leaving any residue.

Research on solubility behavior of iminostilbene in twelve mono-solvents: Measurement, modeling, molecular simulation and thermodynamic properties

Iminostilbene (IMB) is an important pharmaceutical intermediate that can be used to prepare the antiepileptic drug omazepine. The measurement of solid–liquid equilibrium solubility parameters in various solvents can be employed for crystallization and separation processes of IMB. In this research, mole-fraction solubility of IMB in twelve individual organic solvents namely: “methyl acetate (MeAC), ethyl acetate (EtAC), n-propyl acetate (NPAC), isopropyl acetate (IPAC), n-butyl acetate (NBAC), isobutyl acetate (IBAC), N-methylpyrrolidone (NMP), acetone (DMK), N,N-dimethylformamide (DMF), acetonitrile (MeCN), N,N- dimethylacetamide (DMAC) and 1,4-dioxane (Diox)” was critically evaluated ranged from 278.15/288.15 K to 323.15 K at 0.1 MPa using laser monitoring method. Experimental solubility data had a general uptrend with the incremental temperature. Simultaneously, IMB solubility in selected mono-solvents showed an obvious order from high to low of: NMP > DMAC > DMF > Diox > DMK > NBAC > NPAC > EtAC > IBAC > IPAC > MeAC > MeCN. In order to explore dissolution behavior, Hirshfeld surface as well as molecular electrostatic potential surface (MEPs) were employed to analyze intermolecular interaction, and result indicated hydrogen bonding was easily formed on >NH group and its opposite position CHCH group. Meanwhile, Hansen solubility parameters (HSPs) were used to investigate solubility order, the result of which suggested that dispersion interaction could be the main factor influenced on solubility order in homologous solvents. Moreover, four activity coefficient models (Margules, UNIQUAC, NRTL, NRTL-SAC model) as well as a combined equation (Jouyban model) were applied for correlation of solubility data with twelve solvents. UNIQUAC model provided the highest regression accuracy among five models in terms of average relative deviation (ARD) lower than 1.178 % and root mean square deviation (RMSD) not higher than 1.176 ‰. Furthermore, based on UNIQUAC equation, thermodynamic properties including dissolution and mixing process were strictly evaluated for further research on solubility behavior. The results demonstrated that both of mixing and dissolution behaviors were spontaneous and entropically driven.

Decoration, Characterization and Antimicrobial Activity Evaluation of Novel Nano‐Based 1,2‐Phenylenediamine Functionalized Maleic Anhydride‐Allylphenyl Ether Conjugate

Abstract1,2‐Phenylenediamine (o‐PDA) is a well‐known fluorescent dye that enables the decoration of next‐generation chemotherapeutics. A novel o‐PDA‐functionalized maleic anhydride‐allyl phenyl ether (poly(MA‐alt‐APE)/o‐PDA conjugate) was successfully synthesized according to the Ringsdorf model, which is the starting point for macromolecular prodrugs. Functional polymeric‐carriers were prepared by free‐radical polymerization in butyl acetate with azobisisobutyronitrile (AIBN) radical‐initiator at 70 °C. The conjugation was carried out at 40 °C in N,N‐dimethylformamide (DMF) using triethylamine (Et3N) as the conjugation catalyst. Characterization was performed by Attenuated Total Reflectance‐Fourier Transform Infrared (ATR‐FTIR), Nuclear Magnetic Resonance (1H‐NMR), UV‐Vis and Fluorescence Spectroscopy. Weight average molecular weight (Mw), number average molecular weight (Mn) and polydispersity index (PDI) (Mw/Mn) were calculated using gel permeation chromatography (GPC). The surface morphology was also elucidated by Transmission Electron Microscopy (TEM). Evaluation of antimicrobial activity against two Gram‐positive bacteria (Staphylococcus aureus, Bacillus cereus), two Gram‐negative bacteria (Escherichia coli, Pseudomonas aeruginosa) and one yeast Candida albicans was performed using the broth microdilution method according to Clinical Laboratory Standards Institute (CLSI) criteria. Interestingly, S. aureus was found to be more sensitive to polymer‐based samples and, in particular, the minimum inhibitory concentration (MIC) of the conjugate was lower than that of ciprofloxacin used as a control compound.

Investigation on solid–liquid equilibrium behavior of 4-cyanobenzoic acid in fourteen mono-solvents: Determination, correlation, molecular simulation and thermodynamic analysis

4-Cyanobenzoic acid (4-CyBZA) is an important pharmaceutical intermediate, and the research on solubility behavior of 4-CyBZA in organic solvents is very necessary for its crystallization and separation processes. Therefore, this study aimed at exploring dissolution behavior of 4-CyBZA in several pure solvents via experiment, calculation, and simulation process. In this study, mole-fraction solubility values of 4-CyBZA in fourteen common solvents including four low alcohols (methanol (MeOH), ethanol (EtOH), n-propanol (NPOH), n-butanol (NBOH)), four acetates (methyl acetate (MeAC), ethyl acetate (EtAC), n-propyl acetate (NPAC), n-butyl acetate (NBAC)), two alcohol ethers (2-ethoxyethanol (EGEE), 2-methoxyethanol (EGME)) as well as four common heteroatom/heterocyclic solvents (acetonitrile (MeCN), N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), 1,4-dioxane (Diox)) were critically measured by using laser monitoring method from 278.15/288.15 K to 323.15 K under 100 kPa. Interestingly, experimental results indicated that an increase in temperature facilitated the dissolution of 4-CyBZA in selected 14 solvents. At the same time, the solubility curve underwent a crossover phenomenon. At 298.15 K, the common order of 4-CyBZA solubility was: DMF > EGME > EGEE > NMP > Diox > MeOH > MeAC > EtOH > EtAC > NPAC > NPOH > NBOH > NBAC > MeCN. The Hansen solubility parameter (HSP) was introduced to analyze solubility behavior via molecular similarity between 4-CyBZA and chosen solvents. Molecular modeling including Hirshfeld surface (HS) analysis and molecular electrostatic potential surface (MEPS) were employed to understand internal interactions within 4-CyBZA crystals. Moreover, solubility was fitted by Margules model, NRTL model, NRTL-SAC model, UNIQUAC model as well as a combined model (Jouyban model). Results showed that NRTL and NRTL-SAC model were more suitable for correlating 4-CyBZA solubility with absolute temperature. Furthermore, given the high accuracy of the NRTL model, dissolution thermodynamic characteristics of 4-CyBZA in chosen solvents were analyzed by NRTL model, which revealed that the dissolving process and mixing process were spontaneous and entropy-driven.

SOLVATOCHROMIC PROPERTIES OF SOME 6,7-DIHYDROXYBENZOPYRYLLIUM PERCHLORATE DERIVATIVES

The creation of new reagents based on benzopyrylium derivatives with improved che­mical-analytical characteristics is of interest because their preparative synthesis is relatively simple and consists in the condensation of triatomic phenols with β-dicarbonyl compounds. Benzopyryllium derivatives are reactive compounds and are able to redox reactions, complexes formation with polyvalent metal ions, and are also prone to acid-base transformations in solutions. It should be noted separately that hydroxyderivatives of ben­zopyrylium during complex formation can turn into anhydro bases with a quinoid structure, which leads to a significant bathochromic shift of the absorption band and an increase in the contrast of analytical reactions. The current work is devoted to the study of solvatochromic pro­perties of a number of 6,7-dihydroxybenzopyrylium perchlorate derivatives: 6,7-dihyd­roxy-2,4-dimethylbenzopyrylium, 6,7-dihyd­roxy-2-phenyl-4-methylbenzopyrylium and 6,7-di­hyd­roxy-2,4 -diphenylbenzopyrylium. The presented work is a continuation of research on synthesis, acid-base and complexation of 6,7-­dihyd­roxybenzopyrylium derivatives. The influence of the nature of organic solvents was stu­died using the example of methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, n-pentanol, iso-pentanol, n-hexanol, n-heptanol, n-nonanol, decanol, dimethylformamide, dimethyl sulfoxide, tetrahydrofuran, acetonitrile, butyl acetate, toluene, and chloroform. It is shown that when a polar solvent is replaced by a less polar one, a bathochromic shift of the maximum of the absorption band of 6,7-dihydroxybenzopyrylium derivatives is observed, which corresponds to the n→π* electronic transition. It was noted that there is a satisfactory correlation (R = 0.795–0.993) between the position of the maximum absorption of the dye and the values of the Hansen parameter, Kamlet – Taft, donor and acceptor number according to Gutman.