Artigos de revistas: "Molecular solvents"

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Paul, Lucas, Geradius Deogratias, Daniel M. Shadrack, Celestin N. Mudogo, Kelvin M. Mtei, Revocatus L. Machunda, Andrew S. Paluch e Fidele Ntie-Kang. "A Molecular Investigation of the Solvent Influence on Inter- and Intra-Molecular Hydrogen Bond Interaction of Linamarin". Processes 10, n.º 2 (11 de fevereiro de 2022): 352. http://dx.doi.org/10.3390/pr10020352.

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Linamarin has been reported to have anticancer activities; however, its extraction and isolation using different solvents yield a low amount. Therefore, understanding the physical properties, such as solvents’ solubility, membrane permeability and lipophilicity and how they are associated with different solvents, is a paramount topic for discussion, especially for its potential as a drug. Linamarin has a sugar moiety with many polar groups responsible for its physical properties. Following current trends, a molecular dynamics simulation is performed to investigate its physical properties and how different solvents, such as water, methanol (MeOH), dimethyl sulfoxide (DMSO) and dichloromethane (DCM), affect such properties. In this work, we have investigated the influence of intermolecular and intramolecular hydrogen bonding and the influence of polar and non-polar solvents on the physical properties of linamarin. Furthermore, solvation free-energy and electronic structure analysis are performed. The structural analysis results show that the polar groups of linamarin have strong interactions with all solvents except the etheric oxygen groups. A detailed analysis shows intermolecular hydrogen bonding between polar solvents (water, MeOH and DMSO) and the hydroxyl oxygens of linamarin. Water exhibits the strongest interaction with linamarin’s functional groups among the investigated solvents. The findings show that within the first solvation shell, the number of water molecules is greatest, while MeOH has the fewest. Centrally to the structural analysis, solvation free energy confirms DMSO to be the best solvent since it prefers to interact with linamarin over itself, while water prefers to interact with itself. While the solute–solvent interactions are strongest between linamarin and water, the solvent–solvent interactions are strongest in water. As a result, the solvation free-energy calculations reveal that linamarin solvation is most favourable in DMSO.

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Wu, Yin, e Yan Sun. "Cationic Polymers Remarkably Boost Haloalkane Dehalogenase Activity in Organic Solvent Solutions and the Molecular Implications". Molecules 28, n.º 19 (25 de setembro de 2023): 6795. http://dx.doi.org/10.3390/molecules28196795.

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Applications of haloalkane dehalogenase DhaA in biocatalysis are limited by its unfavorable performance in organic solvents. Our previous work proved that mutations of surface positive-charged residues enhanced the organic solvent resistance of DhaA, which inspired us to explore the effect of cationic polymers on DhaA in organic solvents. Remarkably boosted performance was achieved in different organic solvent solutions by introducing cationic polymers, for example, there was a 6.1-fold activity increase with poly(allylamine hydrochloride) and a 5.5-fold activity increase with poly(ethylene imine) in 40 vol.% dimethylsulfoxide. The presence of cationic polymers protected DhaA from damage by organic solvents and increased the substrate concentration around the enzyme-polymer complex. Fluorescence spectroscopy and molecular dynamics simulations revealed that the binding of cationic polymers onto DhaA weakened the interactions between organic solvents and DhaA, decreased the organic solvent solvation level around DhaA, and enhanced the structural stability of DhaA in organic solvents. This comprehensive understanding of the effect of cationic polymers on DhaA can help to broaden the applications of DhaA in organic solvent-involved biocatalysis.

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Krienke, H. "Thermodynamical, structural, and dielectric properties of molecular liquids from integral equation theories and from simulations". Pure and Applied Chemistry 76, n.º 1 (1 de janeiro de 2004): 63–70. http://dx.doi.org/10.1351/pac200476010063.

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A survey is given on our attempts to calculate equilibrium properties of molecular liquids (pure solvents and electrolyte solutions) with the help of spatial pair correlation functions, starting from classical molecular pair interactions. The selection of potential models, especially the influence of molecular polarizability, is discussed as well as the limitations of the different methods of calculation of molecular pair correlation functions (e.g., from molecular and site-site Ornstein-Zernike theories, from MC and from MD simulations). We have performed simulations and integral equation calculations for spatial distribution functions in pure solvents with very low dielectric constants as dioxane and tetrahydrofurane, up to solvents with a very high dielectric constant like n-methylformamide. Ionic solvation is studied in pure solvent systems as well as in solvent mixtures. The general features of ion solvation and association, of the solvent structure around solutes, and their influence on solution properties, are discussed in the framework of the different theoretical approaches.

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Pham, Quoc Dat, Daniel Topgaard e Emma Sparr. "Tracking solvents in the skin through atomically resolved measurements of molecular mobility in intact stratum corneum". Proceedings of the National Academy of Sciences 114, n.º 2 (27 de dezembro de 2016): E112—E121. http://dx.doi.org/10.1073/pnas.1608739114.

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Solvents are commonly used in pharmaceutical and cosmetic formulations and sanitary products and cleansers. The uptake of solvent into the skin may change the molecular organization of skin lipids and proteins, which may in turn alter the protective skin barrier function. We herein examine the molecular effects of 10 different solvents on the outermost layer of skin, the stratum corneum (SC), using polarization transfer solid-state NMR on natural abundance 13C in intact SC. With this approach it is possible to characterize the molecular dynamics of solvent molecules when present inside intact SC and to simultaneously monitor the effects caused by the added solvent on SC lipids and protein components. All solvents investigated cause an increased fluidity of SC lipids, with the most prominent effects shown for the apolar hydrocarbon solvents and 2-propanol. However, no solvent other than water shows the ability to fluidize amino acids in the keratin filaments. The solvent molecules themselves show reduced molecular mobility when incorporated in the SC matrix. Changes in the molecular properties of the SC, and in particular alternation in the balance between solid and fluid SC components, may have significant influences on the macroscopic SC barrier properties as well as mechanical properties of the skin. Deepened understanding of molecular effects of foreign compounds in SC fluidity can therefore have strong impact on the development of skin products in pharmaceutical, cosmetic, and sanitary applications.

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da Silva, Guilherme C. Q., Thiago M. Cardozo, Giovanni W. Amarante, Charlles R. A. Abreu e Bruno A. C. Horta. "Solvent effects on the decarboxylation of trichloroacetic acid: insights from ab initio molecular dynamics simulations". Physical Chemistry Chemical Physics 20, n.º 34 (2018): 21988–98. http://dx.doi.org/10.1039/c8cp02455c.

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Fleischfresser, B. E., e G. C. Smith. "Sorption of Carboxylic Acids by Wool: Effect of Solvents". Textile Research Journal 58, n.º 4 (abril de 1988): 221–26. http://dx.doi.org/10.1177/004051758805800406.

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The sorption of low molecular weight carboxylic acids by wool from various solvents has been investigated. More extensive sorption was observed from neutral than from either basic or acidic solvents. These results may be rationalized in terms of acid-base interactions between solvent, wool, and carboxylic acids. Basic solvents inhibit sorption by competing with the wool for the acids, whereas acidic solvents inhibit sorption by competing with the carboxylic acids for the wool. Water, an amphoteric solvent, gives limited sorption of acids compared with that found from neutral solvents.

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Nyquist, R. A., T. M. Kirchner e H. A. Fouchea. "Vibrational Frequency Shifts of the Carbonyl Stretching Mode Induced by Solvents: Acetone". Applied Spectroscopy 43, n.º 6 (agosto de 1989): 1053–55. http://dx.doi.org/10.1366/0003702894203741.

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Variation in the correlations obtained between electron acceptor number (AN) values for each solvent versus the vC=O frequencies for acetone and tetramethylurea in solution with these solvents suggests that the AN values are not a precise measure of solute/solvent interaction for all solute/solvent systems. Factors such as intermolecular hydrogen bonding between solute and solvent and the differences between molecular geometry of the solutes and solvents most likely account for differences in the solute/solvent interaction for different solutes in the same solvents.

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Ooi, Jecksin, Denny K. S. Ng e Nishanth Chemmangattuvalappil. "A systematic molecular design framework for an environmentally benign solvent recovery process". MATEC Web of Conferences 268 (2019): 02001. http://dx.doi.org/10.1051/matecconf/201926802001.

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Computer Aided Molecular Design (CAMD) techniques have been extensively applied to design solvents for different applications. Most of the CAMD problems only aim at generating solvents that meet the predefined functionality. Nevertheless, it is important to consider the effect of solvent on the safety, health and environmental impacts during the recovery process. This paper presents a single stage CAMD framework that simultaneously quantifies the environmental impact of the solvent recovery process. The environmental impact of the process can be estimated through IChemE Sustainability Metrics. Besides, molecular properties that have an impact on the quantitative evaluation of the environmental impact of solvent recovery process are included in this framework. Weighted sum method coupled with Fuzzy Analytic Hierarchy Process (FAHP) weighting approach is employed to solve the multi-objective molecular design framework. A case study on solvent design for residual oil extraction from palm pressed fiber is presented to illustrate the proposed framework. In this work, only energy balance around multistage evaporator is incorporated into CAMD formulation as energy required to recover the solvent contributes to the largest portion of the whole process. The results show that the designed solvents simultaneously possess target functionalities and reduce the environmental impact of solvent recovery process.

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Ye, Kairu, Yan Yang, Haishuo Chen, Jiatong Wu, Hongyuan Wei e Leping Dang. "Investigation into Pigmentation Behaviors and Mechanism of Pigment Yellow 180 in Different Solvents". Processes 11, n.º 10 (11 de outubro de 2023): 2951. http://dx.doi.org/10.3390/pr11102951.

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To achieve the target colors, pigmentation (post-processing) in solvents is a key process in making Pigment Yellow 180 (PY180), a bis azo pigment. In this work, the solvent effect on the pigmentation behavior of PY180 was studied based on the Hansen solubility parameters (HSPs) and the molecular polarity index (MPI) method. First, the samples were characterized using FTIR, XRD, and TEM, and the colorimetric analysis was performed using the CIE L*a*b* color space model. It was found that the color hues obtained in ten solvents are different, with the overall color variation from reddish–yellow to greenish–yellow. Further characterization confirmed that the crystallinity and particle size increase of PY180 during the pigmentation mainly account for the variation of the chromaticity. Then, HSPs were introduced to understand how suspension behavior affects the dissolution–reprecipitation process. It shows that high-quality pigments can be obtained from solvents generally with low HSP differences (Δδ) between the solvents and PY180. To compensate for the inaccurate prediction of the HSPs method, MPI was used to value the influence of solvent molecular polarity. The results show that among solvents with similar solubility parameters to PY180, the stronger the molecular polarity index (MPI) of the solvent, the greater the color variation of the pigments. Meanwhile, different solvents influence the crystallization behavior of the low soluble system, which was supplemented by the above study.

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Cysewski, Piotr, Tomasz Jeliński e Maciej Przybyłek. "Experimental and Theoretical Insights into the Intermolecular Interactions in Saturated Systems of Dapsone in Conventional and Deep Eutectic Solvents". Molecules 29, n.º 8 (11 de abril de 2024): 1743. http://dx.doi.org/10.3390/molecules29081743.

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Solubility is not only a crucial physicochemical property for laboratory practice but also provides valuable insight into the mechanism of saturated system organization, as a measure of the interplay between various intermolecular interactions. The importance of these data cannot be overstated, particularly when dealing with active pharmaceutical ingredients (APIs), such as dapsone. It is a commonly used anti-inflammatory and antimicrobial agent. However, its low solubility hampers its efficient applications. In this project, deep eutectic solvents (DESs) were used as solubilizing agents for dapsone as an alternative to traditional solvents. DESs were composed of choline chloride and one of six polyols. Additionally, water–DES mixtures were studied as a type of ternary solvents. The solubility of dapsone in these systems was determined spectrophotometrically. This study also analyzed the intermolecular interactions, not only in the studied eutectic systems, but also in a wide range of systems found in the literature, determined using the COSMO-RS framework. The intermolecular interactions were quantified as affinity values, which correspond to the Gibbs free energy of pair formation of dapsone molecules with constituents of regular solvents and choline chloride-based deep eutectic solvents. The patterns of solute–solute, solute–solvent, and solvent–solvent interactions that affect solubility were recognized using Orange data mining software (version 3.36.2). Finally, the computed affinity values were used to provide useful descriptors for machine learning purposes. The impact of intermolecular interactions on dapsone solubility in neat solvents, binary organic solvent mixtures, and deep eutectic solvents was analyzed and highlighted, underscoring the crucial role of dapsone self-association and providing valuable insights into complex solubility phenomena. Also the importance of solvent–solvent diversity was highlighted as a factor determining dapsone solubility. The Non-Linear Support Vector Regression (NuSVR) model, in conjunction with unique molecular descriptors, revealed exceptional predictive accuracy. Overall, this study underscores the potency of computed molecular characteristics and machine learning models in unraveling complex molecular interactions, thereby advancing our understanding of solubility phenomena within the scientific community.

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Alvira, Elena. "Molecular Simulation of the Separation of Isoleucine Enantiomers by β-Cyclodextrin". Molecules 24, n.º 6 (14 de março de 2019): 1021. http://dx.doi.org/10.3390/molecules24061021.

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Molecular mechanics and dynamics simulations were carried out to study the capacity of isoleucine enantiomers to form inclusion complexes with β–cyclodextrin, and to be discriminated by this chiral compound, in vacuo and with different solvents. Solvents were characterized not only by the value of dielectric constant ε in the Coulombic interaction energy, but also by the neutral and zwitterion configurations of isoleucine. Whereas the discrimination between the enantiomers for ε ≤ 2 is due to the electrostatic contribution, these differences are mainly due to the Lennard-Jones potential for ε > 2. The most enantioselective regions are located near the cavity walls, independently of the solvent. D-Ile is more stable than L-Ile in broader regions in vacuo, but L-Ile presents more stable locations with water. Isoleucine can form inclusion complexes with β–cyclodextrin in vacuo and with different solvents. Two probable configurations are deduced from the molecular dynamics simulation, in which the guest is always inside the cavity and with the carboxylic end of the amino acid oriented towards either rim of β–CD. In the simulation, the enantiomers preferentially occupy regions with greater chiral discrimination. The first eluted enantiomer in vacuo and with different solvents is L-Ile, independently of the solvent polarity.

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Nakapraves, Siya, Monika Warzecha, Chantal L. Mustoe, Vijay Srirambhatla e Alastair J. Florence. "Prediction of Mefenamic Acid Crystal Shape by Random Forest Classification". Pharmaceutical Research 39, n.º 12 (dezembro de 2022): 3099–111. http://dx.doi.org/10.1007/s11095-022-03450-4.

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Abstract Objective Particle shape can have a significant impact on the bulk properties of materials. This study describes the development and application of machine-learning models to predict the crystal shape of mefenamic acid recrystallized from organic solvents. Methods Crystals were grown in 30 different solvents to establish a dataset comprising solvent molecular descriptors, process conditions and crystal shape. Random forest classification models were trained on this data and assessed for prediction accuracy. Results The highest prediction accuracy of crystal shape was 93.5% assessed by fourfold cross-validation. When solvents were sequentially excluded from the training data, 32 out of 84 models predicted the shape of mefenamic acid crystals for the excluded solvent with 100% accuracy and a further 21 models had prediction accuracies from 50–100%. Reducing the feature set to only solvent physical property descriptors and supersaturations resulted in higher overall prediction accuracies than the models trained using all available or another selected subset of molecular descriptors. For the 8 solvents on which the models performed poorly (< 50% accuracy), further characterisation of crystals grown in these solvents resulted in the discovery of a new mefenamic acid solvate whereas all other crystals were the previously known form I. Conclusions Random forest classification models using solvent physical property descriptors can reliably predict crystal morphologies for mefenamic acid crystals grown in 20 out of the 28 solvents included in this work. Poor prediction accuracies for the remaining 8 solvents indicate that further factors will be required in the feature set to provide a more generalized predictive morphology model.

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Hao, Hong, Guozheng Liang e Junmin Zhao. "Gelation Crystallization of Poly(L-Lactide) in Solvents of Varying Molecular Size". Polymers and Polymer Composites 15, n.º 5 (julho de 2007): 389–93. http://dx.doi.org/10.1177/096739110701500506.

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The crystallization behaviour of poly(L-lactide) (PLLA) samples prepared in large-molecule solvents, such as poly(ethylene glycol) (PEG), was studied by differential scanning calorimetry (DSC) and X-ray diffraction. The results indicate that those samples recovered from large-molecule solvents exhibit higher crystallinity, non-isothermal crystallization temperature and faster crystallization rate than the ones crystallized in a small-molecule solvent. The crystallinity of samples from PLLA/PEG gel is about 73% measured by the DSC. The molar size of the solvent has a large influence on the formation of helical conformations and, thereby on the crystallization rate of PLLA in solution.

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Schuur, Boelo, Thomas Brouwer e Lisette M. J. Sprakel. "Recent Developments in Solvent-Based Fluid Separations". Annual Review of Chemical and Biomolecular Engineering 12, n.º 1 (7 de junho de 2021): 573–91. http://dx.doi.org/10.1146/annurev-chembioeng-102620-015346.

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The most important developments in solvent-based fluid separations, separations involving at least one fluid phase, are reviewed. After a brief introduction and discussion on general solvent trends observed in all fields of application, several specific fields are discussed. Important solvent trends include replacement of traditional molecular solvents by ionic liquids and deep eutectic solvents and, more recently, increasing discussion around bio-based solvents in some application fields. Furthermore, stimuli-responsive systems are discussed; the most significant developments in this field are seen for CO2-switchable and redox-responsive solvents. Discussed fields of application include hydrocarbons separations, carbon capture, biorefineries, and metals separations. For all but the hydrocarbons separations, newly reported electrochemically mediated separations seem to offer exciting new windows of opportunities.

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Gonçalves, P. F. B., e H. Stassen. "Calculation of the free energy of solvation from molecular dynamics simulations". Pure and Applied Chemistry 76, n.º 1 (1 de janeiro de 2004): 231–40. http://dx.doi.org/10.1351/pac200476010231.

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Molecular dynamics simulation has been employed in the computation of the free energy of solvation for a large number of solute molecules with different chemical functionalities in the solvents water, acetonitril, dimethyl sulfoxide, tetrahydrofuran, and carbon disulfide. The free solvation energy has been separated into three contributions: the work necessary to create a cavity around the solute in the solvent, the electrostatic contribution, and the free energy containing the short-range interactions between solute and solvent molecules. The cavitational contribution was computed from the Claverie-Pierotti model applied to excluded volumes obtained from nearest-neighbor solute-solvent configurations treating the solvent molecules as spherical. The electrostatic term was calculated from a dielectric continuum approach with explicitly incorporating the solvent's partial charges. The short-range contribution to the free solvation energy was obtained from the force field employed in the simulations. For solutions with available experimental data for the free energy of solvation, we found a satisfactory agreement of the computed free solvation energies and the experimental data set.

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Panthi, Bikash, e Nurapati Pantha. "Hydrophobicity of small alkane molecules (propane dimer) in solvents: a classical molecular dynamics study". BIBECHANA 17 (1 de janeiro de 2020): 1–12. http://dx.doi.org/10.3126/bibechana.v17i0.25504.

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Molecular Dynamics (MD) simulations of propane dimer in different solvents (water, acetonitrile and methanol) were performed by using CHARMM platform for modeling the solute and solvents. A series of Umbrella sampling MD simulations were carried out in each solvent separately and potential of mean force (PMFs) were calculated by using Weighted Histogram Analysis Method. Results show that two minima (contact minima and solvent separated minima) characterize the PMF of propane dimer in all three solvent environments. The contact minima are deeper and less sensitive to solvent environment for its position. However, significant effect in the position of second minima, solvent separated minima, was observed. Our study reveals that the interaction between propane dimer is softer in methanol and acetonitrile than in water. BIBECHANA 17 (2020) 1-12

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Kuznetsov, P. N., Z. R. Ismagilov, L. I. Kuznetsova, B. Avid, X. Fan e Е. S. Mihkailova. "The Composition and Properties of Soluble Products from the Coal ThermoSolvolysis with Hydrocarbon Residues and Blends as Solvents". Eurasian Chemico-Technological Journal 24, n.º 3 (10 de outubro de 2022): 183–90. http://dx.doi.org/10.18321/ectj1431.

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The dissolution of bituminous coal at mild temperature was studied using a variety of commercially available coal- and petroleum-derived hydrocarbon fractions, hydrorefined derivatives and blends as solvents. The chemical and molecular composition of the coal, solvents and extracts were characterized by chemical and group analyses, and by IRFT, 1H NMR, GC-MS and liquid chromatography. Low volatile solvents like highly aromatic coal tar (CT), its anthracene fraction (AFCT), petroleum-derived solvent (HGOCC) and binary blends were found to exhibit high performance for coal dissolution into quinoline solubles (to 79‒82%), and the yields of gases being no more than 0.5%. The extracts obtained using CT and AFCT solvents represented pitch-like matter consisting of rarely substituted aromatic molecules with 4‒5 condensed rings. HGOCC extract was much less aromatic, the aromatic rings being highly substituted with fairly large alkyl substituents. The blended solvents yielded more extracts, and their molecular indexes were average between those obtained with each solvent separately. A remarkable finding was that the extracts obtained were characterized by significantly lower content of benzo(a) pyrene (BaP) compared to solvents used, its content further decreased as the time of coal dissolution increased.

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Park, Jong-Hyeok, Jiyoung Heo, Soryong Chae e Jin Soo Park. "Performance of Solvent Substituted Ionomer Dispersions in Catalyst Layer for Hydrogen-Based Energy Conversion Devices". ECS Meeting Abstracts MA2023-01, n.º 36 (28 de agosto de 2023): 2082. http://dx.doi.org/10.1149/ma2023-01362082mtgabs.

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Catalyst inks for the preparation of porous catalyst layer for hydrogen-based energy conversion devices is composed of electrocatalyst, ionomer dispersion and additional solvents. Solvents have an important role in determining the size of ionomer aggregates, the properties of catalyst ink and the morphology of catalyst layer. It has been reported that the solvents for ionomer dispersions substantially influenced the size of ionomer aggregates and finally resulted in the performance and durability. To understand a deep insight into solvent-ionomer molecular interaction, solvation energy obtained by molecular design modeling for a measurement of the relative solubility of ionomers in solvents was studied in this study. In this study, we investigated the solvent-ionomer molecular interaction using molecular design modeling simulation and experimental validation in proton exchange membrane fuel cell and water electrolysis. In addition, I-V polarization curves, cyclic voltammetry and electrochemical impedance spectroscopy were measured and analyzed in terms of solvent property and solvation energy. Acknowledgment This research was supported in part by the Hydrogen Energy Innovation Technology Development Program of the National Research Foundation (NRF) funded by the Ministry of Science, ICT & Future Planning(NRF-2019M3E6A1063677) and by the New and Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea (No. 20213030040520).

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Egorov, V. I., e O. G. Maksimova. "Dependence of the relaxation properties of polypropylene solutions on the concentration of organic solvents: molecular dynamics simulation". Известия Российской академии наук. Серия физическая 87, n.º 9 (1 de setembro de 2023): 1316–21. http://dx.doi.org/10.31857/s0367676523702319.

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The microscopic relaxation of polymer chains in organic solvents has been studied by the molecular dynamics method. The simulation was carried out for the mixtures of polypropylene with three different organic solvents (acetone, cyclopentane, acetonitrile). The dependence of the relaxation time and the glass transition temperature of the polymer on the mass fraction of the solvent is obtained.

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Yushkin, Alexey A., Alexey V. Balynin, Danila S. Bakhtin, Richard Kirk, Peter M. Budd e Alexey V. Volkov. "Cross-Linked PIM-1 Membranes with Improved Stability to Aromatics". Key Engineering Materials 869 (outubro de 2020): 431–36. http://dx.doi.org/10.4028/www.scientific.net/kem.869.431.

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Composite membranes were prepared for nanofiltration of aromatic solvents. Cross-linking with AlCl3 was used to improve the stability of the PIM-1 selective layer in aromatic solvents like toluene, benzene and xylene. Nanofiltration performances of obtained membranes were tested with 4 different aromatic hydrocarbons and with 3 solvents from other classes of solvents. Obtained permeability for aromatic hydrocarbons was above 8,5 kg/m2·h·bar and retention of Remazol brilliant blue R dye with molecular mass 626 was up to 96 %. It was shown that permeability results correlated with Hansen solubility parameter and distance parameter between polymer and solvent. PIM-1 has higher permeability for non-polar hydrocarbons due to higher affinity between polymer and solvent.

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Jin, Wenbin, Yuqi Ke, Xianxian Liu, Qiwei Yang, Zongbi Bao, Baogen Su, Qilong Ren, Yiwen Yang e Huabin Xing. "Enhanced self-assembly for the solubilization of cholesterol in molecular solvent/ionic liquid mixtures". Physical Chemistry Chemical Physics 19, n.º 17 (2017): 10835–42. http://dx.doi.org/10.1039/c7cp01098b.

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Faramarzi, Hamed, Masoud Rahimi, Hamidreza Mahdavi e Saber Niazi. "Development of a Molecular Dynamics Model to Assess the Possibility of Type II/III Porous Liquid Formation". Processes 12, n.º 4 (10 de abril de 2024): 762. http://dx.doi.org/10.3390/pr12040762.

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The study of porous liquids (PLs) using molecular dynamics (MD) simulation is one of the most interesting and attractive research topics. The possibility of creating permanent porosity in a solvent and increasing its adsorption capacity is very practical. The purpose of the present study is to examine how an MD model can be developed to evaluate the possibility of PL formation. Additionally, the validation of the model was conducted by simulations using two metal–organic frameworks (MOFs) including zeolitic imidazolate framework-8 (ZIF-8) and Hong Kong University of Science and Technology-1 (HKUST-1) as porogens and water (H2O) and triethylene glycol (TEG) as solvents. The results revealed that H2O and TEG are incapable of penetrating the ZIF-8 pores due to their small size and unfavorable thermodynamics; however, both solvents easily penetrate through the large HKUST-1 pores. These observations aligned with findings from experimental literature studies, thus confirming the validity of the model. In order to expand the model’s scope, the developed model was used to assess the possibility of PL formation using ZIF-8 and HKUST-1 with different pore and window sizes and shapes, and a wide range of hydrocarbon liquids with different molecular sizes and shapes as solvents. It was found that ZIF-8 can form PLs with a more extensive range of sterically hindered solvents due to its smaller apertures and incompatible shape. In addition, only a few solvents (e.g., n-pentane, benzene, 1,3,5-trimethylbenzene, 1,3,5-triisopropylcyclohexane, and 1,3,5-triisopropylbenzene) can partially penetrate its ZIF-8 pores without steric hindrance. These privileged solvents typically have an aspect ratio far from 1, indicating a more elongated shape, and/or more linear branches. In contrast, HKUST-1, which has larger apertures and a compatible shape, allows for complete penetration of specific solvents (e.g., benzene, iso-octane, n-pentane), thereby preventing PL formation with such combinations. In addition, cyclohexane has the ability to partially penetrate the pores of HKUST-1. Therefore, in addition to the size of the solvent molecule, one of the most important properties for penetration is the compatibility of the shape of the porogen pore window with the shape of the solvent molecule. This research provides important new information on how PLs come to be by illuminating the role that solvent molecules and porogen play in promoting penetration and, in the end, impacting the process of PL formation.

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Liu, Bin, Yanan Yu, Hanlin Liu, Zhe Cui e Wende Tian. "Multi-Criteria Screening of Organic Ethanolamines for Efficient CO2 Capture Based on Group Contribution Method". Processes 11, n.º 5 (16 de maio de 2023): 1524. http://dx.doi.org/10.3390/pr11051524.

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Amine solvent has attracted much attention due to its high CO2 capture level and wide application range, but its high energy consumption for recycling restricts its large-scale commercialization. In this work, a multi-objective optimization technology based on the group contribution method was used to select potential amine solvents for CO2 capture. This computer-aided molecular design method considers the thermodynamic and kinetic properties of the candidate solvent and evaluates the influence of relevant parameters on solvent performance. Compared with previous experimental methods used to optimize solvent, this method selects potential solvents from a large number of solvent databases based on group contribution. Firstly, a corresponding classification database was established for various kinds of amine solvents. Then, the traditional experiments were used to verify and screen solvents. At the same time, the method was applied to 31 amine absorbents concerning solubility, molar volume, surface tension, heat capacity, viscosity, pKa, saturated vapor pressure, and so on, and seven solvents were found to have comparable performance to MEA, with higher absorption rates and solubility. This method provides guidance for screening CO2 capture absorbents with economic viability, high efficiency, fast absorption rates, and low regeneration energy consumption.

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Yalcin, Dilek, Andrew J. Christofferson, Calum J. Drummond e Tamar L. Greaves. "Solvation properties of protic ionic liquid–molecular solvent mixtures". Physical Chemistry Chemical Physics 22, n.º 19 (2020): 10995–1011. http://dx.doi.org/10.1039/d0cp00201a.

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In this study, we have investigated the solvation properties of binary mixtures of PILs with molecular solvents. The selected binary solvent systems are the PILs ethylammonium nitrate (EAN) and propylammonium nitrate (PAN) combined with either water, methanol, acetonitrile or DMSO.

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Yau, Hon Man, Sinead T. Keaveney, Bradley J. Butler, Eden E. L. Tanner, Max S. Guerry, Stephen R. D. George, Michelle H. Dunn, Anna K. Croft e Jason B. Harper. "Towards solvent-controlled reactivity in ionic liquids". Pure and Applied Chemistry 85, n.º 10 (1 de outubro de 2013): 1979–90. http://dx.doi.org/10.1351/pac-con-12-10-22.

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Ionic liquids are frequently touted as alternatives to traditional molecular solvents but are limited in their applicability as the outcome of reactions may be altered on moving from a molecular to an ionic solvent. This manuscript summarizes our progress towards a predictive framework through understanding how ionic solvents affect organic processes, with an emphasis on how these findings might be applied. Particularly, we will consider the importance of the mole fraction of the ionic liquid used, including some hitherto undisclosed results, as well as the importance of understanding the key interactions of the solvent with the components along the reaction coordinate.

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Nedyalkova, Miroslava, Costel Sarbu, Marek Tobiszewski e Vasil Simeonov. "Fuzzy Divisive Hierarchical Clustering of Solvents According to Their Experimentally and Theoretically Predicted Descriptors". Symmetry 12, n.º 11 (24 de outubro de 2020): 1763. http://dx.doi.org/10.3390/sym12111763.

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The present study describes a simple procedure to separate into patterns of similarity a large group of solvents, 259 in total, presented by 15 specific descriptors (experimentally found and theoretically predicted physicochemical parameters). Solvent data is usually characterized by its high variability, different molecular symmetry, and spatial orientation. Methods of chemometrics can usefully be used to extract and explore accurately the information contained in such data. In this order, advanced fuzzy divisive hierarchical-clustering methods were efficiently applied in the present study of a large group of solvents using specific descriptors. The fuzzy divisive hierarchical associative-clustering algorithm provides not only a fuzzy partition of the solvents investigated, but also a fuzzy partition of descriptors considered. In this way, it is possible to identify the most specific descriptors (in terms of higher, smallest, or intermediate values) to each fuzzy partition (group) of solvents. Additionally, the partitioning performed could be interpreted with respect to the molecular symmetry. The chemometric approach used for this goal is fuzzy c-means method being a semi-supervised clustering procedure. The advantage of such a clustering process is the opportunity to achieve separation of the solvents into similarity patterns with a certain degree of membership of each solvent to a certain pattern, as well as to consider possible membership of the same object (solvent) in another cluster. Partitioning based on a hybrid approach of the theoretical molecular descriptors and experimentally obtained ones permits a more straightforward separation into groups of similarity and acceptable interpretation. It was shown that an important link between objects’ groups of similarity and similarity groups of variables is achieved. Ten classes of solvents are interpreted depending on their specific descriptors, as one of the classes includes a single object and could be interpreted as an outlier. Setting the results of this research into broader perspective, it has been shown that the fuzzy clustering approach provides a useful tool for partitioning by the variables related to the main physicochemical properties of the solvents. It gets possible to offer a simple guide for solvents recognition based on theoretically calculated or experimentally found descriptors related to the physicochemical properties of the solvents.

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Wijaya, Emmy C., Frances Separovic, Calum J. Drummond e Tamar L. Greaves. "Activity and conformation of lysozyme in molecular solvents, protic ionic liquids (PILs) and salt–water systems". Physical Chemistry Chemical Physics 18, n.º 37 (2016): 25926–36. http://dx.doi.org/10.1039/c6cp03334b.

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The role of solvent features on enzyme stability was investigated by comparing the conformation and activity of lysozyme in molecular solvents, PILs and salt solutions. Electrostatic interactions and the solvophobic effect dominated at low and high solvent concentrations, respectively.

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Tsukagoshi, Norihiko, e Rikizo Aono. "Entry into and Release of Solvents byEscherichia coli in an Organic-Aqueous Two-Liquid-Phase System and Substrate Specificity of the AcrAB-TolC Solvent-Extruding Pump". Journal of Bacteriology 182, n.º 17 (1 de setembro de 2000): 4803–10. http://dx.doi.org/10.1128/jb.182.17.4803-4810.2000.

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ABSTRACT Growth of Escherichia coli is inhibited upon exposure to a large volume of a harmful solvent, and there is an inverse correlation between the degree of inhibition and the logP OW of the solvent, whereP OW is the partition coefficient measured for the partition equilibrium established between the n-octanol and water phases. The AcrAB-TolC efflux pump system is involved in maintaining intrinsic solvent resistance. We inspected the solvent resistance of ΔacrAB and/or ΔtolC mutants in the presence of a large volume of solvent. Both mutants were hypersensitive to weakly harmful solvents, such as nonane (logP OW = 5.5). The ΔtolC mutant was more sensitive to nonane than the ΔacrAB mutant. The solvent entered the E. coli cells rapidly. Entry of solvents with a log P OW higher than 4.4 was retarded in the parent cells, and the intracellular levels of these solvents were maintained at low levels. The ΔtolC mutant accumulated n-nonane or decane (logP OW = 6.0) more abundantly than the parent or the ΔacrAB mutant. The AcrAB-TolC complex likely extrudes solvents with a log P OW in the range of 3.4 to 6.0 through a first-order reaction. The most favorable substrates for the efflux system were considered to be octane, heptane, and n-hexane.

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WAKISAKA, Akihiro. "Solvent Effects and Molecular Clusters: Especially in Aqueous Organic Solvents." Journal of Synthetic Organic Chemistry, Japan 52, n.º 6 (1994): 478–87. http://dx.doi.org/10.5059/yukigoseikyokaishi.52.478.

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Li, Danning, Yongli Wang, Shuyi Zong, Na Wang, Xin Li, Yuyuan Dong, Ting Wang, Xin Huang e Hongxun Hao. "Unveiling the self-association and desolvation in crystal nucleation". IUCrJ 8, n.º 3 (30 de abril de 2021): 468–79. http://dx.doi.org/10.1107/s2052252521003882.

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As the first step in the crystallization process, nucleation has been studied by many researchers. In this work, phenacetin (PHEN) was selected as a model compound to investigate the relationship between the solvent and nucleation kinetics. Induction times at different supersaturation in six solvents were measured. FTIR and NMR spectroscopy were employed to explore the solvent–solute interactions and the self-association properties in solution. Density functional theory (DFT) was adopted to evaluate the strength of solute–solvent interactions and the molecular conformations in different solvents. Based on these spectroscopy data, molecular simulation and nucleation kinetic results, a comprehensive understanding of the relationship between molecular structure, crystal structure, solution chemistry and nucleation dynamics is discussed. Both the solute–solvent interaction strength and the supramolecular structure formed by the self-association of solute molecules affect the nucleation rate. The findings reported here shed new light on the molecular mechanism of nucleation in solution.

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Yousefinejad, Saeed, Fatemeh Honarasa e Mehrnoosh Chaabi. "New relationship models for solvent–pyrene solubility based on molecular structure and empirical properties". New Journal of Chemistry 40, n.º 12 (2016): 10197–207. http://dx.doi.org/10.1039/c6nj02319c.

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Chen, Gang, Mingzhu Xia, Wu Lei, Fengyun Wang e Xuedong Gong. "Molecular dynamics investigation of the effect of solvent adsorption on crystal habits of hexogen". Canadian Journal of Chemistry 92, n.º 9 (setembro de 2014): 849–54. http://dx.doi.org/10.1139/cjc-2014-0243.

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In this work, a molecular dynamics investigation was performed to study the effect of the solvents acetone and cyclohexanone on the crystal habits of hexogen. The results show that the adsorption energies of hexogen polar faces such as the (002), (210), (111), and (200) faces are larger than that of the nonpolar (020) face. The adsorption interactions of hexogen surfaces with acetone are stronger than those with cyclohexanone. The adsorption interactions consist of van der Waals and electrostatic interactions. The effect of solvents on the crystal growth of hexogen is discussed by comparing the adsorption energy of each crystal face. It may qualitatively predict that if hexogen crystallizes from polar solvents (acetone and cyclohexanone), the morphological importance of polar faces increases, especially in acetone solvent, while the importance of the nonpolar (020) face probably diminishes, even disappears. The theoretical prediction properly explains the different crystal morphologies of hexogen observed experimentally in these two solvents.

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Wu, Xiaoli, Xulin Cui, Qi Wang, Jingtao Wang, Wenjia Wu, Wenpeng Li e Zhongyi Jiang. "Manipulating the cross-layer channels in g-C3N4 nanosheet membranes for enhanced molecular transport". Journal of Materials Chemistry A 9, n.º 7 (2021): 4193–202. http://dx.doi.org/10.1039/d0ta10236a.

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Cross-layer channels display ‘gate effect’ to govern molecular selectivity for lamellar membranes. Membranes with hydrophilic/hydrophobic heterostructured channels acquire elevated polar solvent permeance and polar/nonpolar solvents selectivity.

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Journal, Baghdad Science. "Study the spectroscopic characteristics of Rhodamine B Dye in Ethanol and Methanol mixture and Calculation the Quantum Efficiency". Baghdad Science Journal 9, n.º 2 (3 de junho de 2012): 352–58. http://dx.doi.org/10.21123/bsj.9.2.352-358.

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The effect of ethanol and methanol solvent, and their mixture has been studied on the absorption and fluorescence spectra of laser dye Rhodamine B at concentration of (10-4) Molar at room temperature. The molar absorption coefficient has been determined for mixture which was (3.223) at wave number (18181.8 cm-1), Also the Quantum Efficiency of the two solvents (ethanol and methanol) and their mixture have been calculated ,which was for mixture spectrum (38.94%) and it was larger comparing with other and solvents. The characteristics of spectrum has been determined by calculating (??) of absorption spectrum for the solvents and its mixture at maximum wave number ( ) cm-1 depending on solvent polarity and the transitions between molecular energy levels in each solvent of Rhodamine B dye .

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Ali, Rafed A., Oday Mazin Abdul-Munem e Ahmed Naji Abd. "Study the spectroscopic characteristics of Rhodamine B Dye in Ethanol and Methanol mixture and Calculation the Quantum Efficiency". Baghdad Science Journal 9, n.º 2 (3 de junho de 2012): 352–58. http://dx.doi.org/10.21123/bsj.2012.9.2.352-358.

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The effect of ethanol and methanol solvent, and their mixture has been studied on the absorption and fluorescence spectra of laser dye Rhodamine B at concentration of (10-4) Molar at room temperature. The molar absorption coefficient has been determined for mixture which was (3.223) at wave number (18181.8 cm-1), Also the Quantum Efficiency of the two solvents (ethanol and methanol) and their mixture have been calculated ,which was for mixture spectrum (38.94%) and it was larger comparing with other and solvents. The characteristics of spectrum has been determined by calculating (??) of absorption spectrum for the solvents and its mixture at maximum wave number ( ) cm-1 depending on solvent polarity and the transitions between molecular energy levels in each solvent of Rhodamine B dye .

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Li, Hongfeng, Peng Chen, Wenbin Sun, Lei Zhang e Pengfei Yan. "Solvent triggered structural diversity of triple-stranded helicates: single molecular magnets". Dalton Transactions 45, n.º 7 (2016): 3175–81. http://dx.doi.org/10.1039/c5dt04608d.

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Solvents have been found to be the key for the construction of diverse triple-stranded helicates. Distinct solvent molecules are found to coordinate to the Dy³⁺ centers to replace the original hydrate molecules.

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Zhang, Jingyi, Bin Jiang, Zhiheng Wang, Yongmei Liang, Yahe Zhang, Chunming Xu e Quan Shi. "Molecular characterisation of ambient aerosols by sequential solvent extractions and high-resolution mass spectrometry". Environmental Chemistry 15, n.º 3 (2018): 150. http://dx.doi.org/10.1071/en17197.

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Environmental contextOrganic compounds generally make a large contribution to ambient aerosol fine particles, and can influence atmospheric chemistry. Solvent extraction before mass spectrometry is widely used for the determination of organic compounds in aerosols, but the molecular selectivity of different solvents is unclear. We extracted an aerosol sample with various solvents and show how the organic compound profile obtained by mass spectrometry changes depending on the extracting solvent. AbstractFor a comprehensive characterisation of organic compounds in aerosols, samples collected on a hazy day from Beijing were sequentially extracted with various solvents and analysed by Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Electrospray ionisation (ESI) was used for the MS analysis. Aerosol samples were extracted in an apolar-to-polar solvent order of n-hexane (n-C6), dichloromethane (DCM), acetonitrile (ACN) and water, and also extracted in reverse sequence. The separated fractions were defined as non-polar, low-polarity, mid-polarity and high-polarity organic compounds respectively. Approximately 70 % of the total organic carbon (TOC) was extractable, of which the water-soluble organic carbon (WSOC) and non-polar organic carbon accounted for 30 and 25 % of the TOC respectively. Non-polar and low-polarity compounds with a high degree of molecular condensation such as oxidised polycyclic aromatic hydrocarbons (PAHs) and nitrogen-containing compounds (CHN) were extracted by n-C6 and DCM. Water-soluble organic matter (WSOM) was predominant with aliphatic and aromatic organosulfates (CHOS) and nitrooxy-organosulfates (CHONS). Most oxygen-containing compounds (CHO) and oxygen- and nitrogen-containing compounds (CHON) with high double-bond equivalents (DBEs) and long carbon chains tended to be extracted into organic solvents.

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Li, Yi, Eric Wong, Alexander Volodine, Chris Van Haesendonck, Kaisong Zhang e Bart Van der Bruggen. "Nanofibrous hydrogel composite membranes with ultrafast transport performance for molecular separation in organic solvents". Journal of Materials Chemistry A 7, n.º 33 (2019): 19269–79. http://dx.doi.org/10.1039/c9ta06169j.

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A polyamide (PA) nanofilm was successfully fabricated on the nanofibrous hydrogel support via controlled interfacial polymerization (IP) and exhibited an unprecedented solvent permeation for various organic solvents.

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Zha, Bao, Xinrui Miao, Yijing Li, Pei Liu, Kai Miao e Wenli Deng. "Solvent-Dependent Self-Assembly of 4,7-Dibromo-5,6-bis(octyloxy)benzo[c][1,2,5] Thiadiazole on Graphite Surface by Scanning Tunneling Microscopy". Journal of Nanomaterials 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/624927.

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Solvent effect on self-assembly of 4,7-dibromo-5,6-bis(octyloxy)benzo[c][1,2,5] thiadiazole (DBT) on a highly oriented graphite (HOPG) surface was investigated by scanning tunneling microscopy (STM) by using 1-phenyloctane, 1-octanoic acid, and 1-octanol as the solvents. Two different patterns were obtained in 1-phenyloctane and 1-octanoic acid, suggesting that the self-assembly of DBT was solvent dependent. At the 1-phenyloctane/HOPG interface, a linear structure was revealed due to the intermolecular halogen bonding. When 1-octanoic acid and 1-octanol are used as the solvents, the coadsorption of solvent molecules resulting from the hydrogen bonding between DBT and solvent made an important contribution to the formation of a lamellar structure. The results demonstrate that solvents could affect the molecular self-assembly according to the variational intermolecular interactions.

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Sheng, Yinghong, e Jerzy Leszczynski. "Theoretical Study of the Substituent and Solvent Effects on the Molecular Structures, Absorption and Emission Spectra of Open-Form Spiropyrans". Collection of Czechoslovak Chemical Communications 69, n.º 1 (2004): 47–62. http://dx.doi.org/10.1135/cccc20040047.

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The effects of substituents and solvents on the molecular structures, excitation energies and emission energies of a series of donor-acceptor substituted spiropyrans were investigated using the density functional methods. Different donor-acceptor pairs lead to alternations of the molecular structures. A relationship between the strengths of donor-acceptor pairs and the structural parameter BLA (bond length alternation) was examined and discussed. The impact on geometrical parameters induced by the solvents is more significant than that caused by the substituents, as indicated by the larger BLA changes. The substituent and solvent effects on the UV absorption and emission spectra of open-form spiropyrans were studied by the TD-DFT method. The absorption maxima of open-form spiropyrans are expected to red shift, and the emission are expected to blue shift as the strengths of donor-acceptor pairs and the polarities of solvents increase. A simple model was adopted to mimic the substituent and solvent effects, in the framework of AM1, employing Sparkles to create an external electric field on the open-form spiropyran, in order to induce a systematical polarization of the molecular equilibrium geometry and the electronic configuration.

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Sun, Shanhu, Haobin Zhang, Jinjiang Xu, Shumin Wang, Hongfan Wang, Zhihui Yu, Lang Zhao, Chunhua Zhu e Jie Sun. "The competition between cocrystallization and separated crystallization based on crystallization from solution". Journal of Applied Crystallography 52, n.º 4 (8 de julho de 2019): 769–76. http://dx.doi.org/10.1107/s1600576719008094.

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The competition between cocrystallization and separated crystallization in a solvent was explored via X-ray diffraction and high-performance liquid chromatography methods in different solvents and by considering the solvent evaporation rate. The results revealed that the solvent system and solvent evaporation rate can affect the nucleation order of the cocrystal and coformers in the solution. In fact, solubility tests in different solvents confirmed that the solubility plays a key role in the cocrystal formation process. Furthermore, the width of the metastable zone influenced the solute nucleation order and was a decisive factor in the cocrystal formation process when the solvent evaporation rate was varied. Cocrystals could therefore be obtained by adjusting the solvents and solvent evaporation rate. The preparation of kinetic 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane–2,4,6-trinitrophenol cocrystals via rapid solvent evaporation proves the practicability of this theory.

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Suhina, Tomislav, Saeed Amirjalayer, Sander Woutersen, Daniel Bonn e Albert M. Brouwer. "Ultrafast dynamics and solvent-dependent deactivation kinetics of BODIPY molecular rotors". Physical Chemistry Chemical Physics 19, n.º 30 (2017): 19998–20007. http://dx.doi.org/10.1039/c7cp02037f.

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The fluorescent excited state of a molecular rotor based on the meso-substituted boron-dipyrromethane (BODIPY) core decays rapidly to the ground state via a conical intersection. The fluorescence is strongly increased in viscous solvents, but solvent polarity has only a small effect.

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Saito, Takamasa, Ryo Takebayashi, Masaki Kubo, Takao Tsukada, Eita Shoji, Gota Kikugawa e Donatas Surblys. "Effect of surface modifier and solvent on the affinity between the surface-modified solid and organic solvent: A molecular dynamics study". AIP Advances 12, n.º 10 (1 de outubro de 2022): 105206. http://dx.doi.org/10.1063/5.0119681.

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To control the dispersibility of surface-modified nanoparticles in fluid, it is important to evaluate the affinity between surface-modified nanoparticles and solvents and elucidate the effect of surface modification on the affinity at the molecular level. In this study, the effect of the chain length of the surface modifier and solvent on the work of adhesion Wadh was investigated for the carboxylic acid-modified Al2O3/ n-alkane interface by molecular dynamics simulations using the phantom-wall method. Here, we adopted hexanoic acid, decanoic acid, and octadecanoic acid as the surface modifiers and n-hexane, n-decane, and n-dodecane as the solvents. At a surface coverage of 100%, the effect of the modifier length on Wadh was small because the solvent did not penetrate any modifier layers with a dense packing state. At a surface coverage of 50%, the solvent penetration was good except for the octadecanoic acid modifier, and Wadh for the decanoic acid modifier was higher than that for the hexanoic acid and octadecanoic acid modifiers. For the decanoic acid modifier with a surface coverage of 50%, the effect of the solvent length on Wadh was small because the density distributions of the modifier and solvent near the interface were almost the same in all solvent systems. Solvent penetration was evaluated using the overlap parameter, which is the degree of overlap of the density distribution. A large penetration resulted in high Wadh. We demonstrated that the affinity between surface-modified nanoparticles and solvents can be increased by ensuring high modifier-solvent penetration via adjusting the surface coverage and surface modifier.

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Naskali, Leila, Maria Engelke e Hanna Tähti. "The Neurotoxicity of Organic Solvents Studied Using Synaptosomes and Neural Cell Cultures". Alternatives to Laboratory Animals 22, n.º 3 (maio de 1994): 175–79. http://dx.doi.org/10.1177/026119299402200307.

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The most common acute neurotoxic effect of organic solvents is their central nervous system (CNS) depressant effect. The molecular mechanism underlying this effect is not known. The purpose of our studies has been to evaluate the adverse effects of organic solvents on the CNS in vitro. Synaptosomal membranes, whole brain reaggregate and astrocyte cultures were studied. Our results suggest that cell membrane integral proteins are targets for solvent impact, but that there are differences among various cell types. In addition to lipophilicity, the structure of solvent molecules seems to be important when considering CNS toxicity. Organic solvents increase the fluidity of the membranes, which may disturb the lipid-protein interaction and the optimal functioning of the enzyme. However, direct effects of solvents on proteins cannot be excluded. In vitro cell models can be used in methods designed to predict acute neurotoxic effects of foreign compounds, and in studies of neurotoxic mechanisms.

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Havránková, Jitka, Zuzana Limpouchová e Karel Procházka. "Monte Carlo Study of Dilute Solutions of Heteroarm Star Copolymers in Solvents Differing in Thermodynamic Quality". Collection of Czechoslovak Chemical Communications 70, n.º 11 (2005): 1848–60. http://dx.doi.org/10.1135/cccc20051848.

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Lattice Monte Carlo simulations (an original modification of the Siepmann and Frenkel simulation variant) was used to study the conformational behavior of heteroarm star copolymers star-(polystyrene; polyisoprene), PS8PI8, in a common good solvent for both types of arms (tetrahydrofuran) and in selective θ-solvents for both types of arms (in cyclohexane, i.e., in θ-solvent for PS and in 1,4-dioxane, i.e. in θ-solvent for PI). Results of simulations were compared with experimental data published by Pispas et al. The coarse graining procedure was performed to match the experimental behavior of heteroarm stars in a good solvent. The computer simulations reproduce all decisive trends of the conformational behavior for both selective solvents. The quantitative agreement between experimental and simulated size characteristics is very good. Simulations yield very detailed information on the system at the molecular level and show that the incompatible arms significantly segregate in selective solvents.

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Zakerhamidi, M. S., S. M. Seyed Ahmadian e R. Kian. "The specific and nonspecific solvatochromic behavior of Sudan dyes in different solvents". Canadian Journal of Chemistry 93, n.º 6 (junho de 2015): 639–47. http://dx.doi.org/10.1139/cjc-2014-0489.

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Absorption and fluorescence spectra of some Sudan dyes (Sudan III, Sudan IV, and Sudan Black B) were recorded in various solvents in the range of 300–800 nm at room temperature. The solvatochromic behavior of these substances and their solvent–solute interactions were analyzed by means of the linear solvation energy relationship concept suggested by Kamlet and Taft. The obtained results express the effect of solvation on the tautomerism and molecular configuration (geometry) of Sudan dyes in solvent media. Furthermore, analysis of solvent–solute interactions suggests different forms of resonance structures of Sudan dyes in polar and low-polar solvents.

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Nadaf, Y. F., G. N. Sushma, M. Suma e Wajeeha Sultana. "SPECTROSCOPIC, MOLECULAR STRUCTURE, FMO AND THERMODYNAMIC PROPERTIES OF 11-CHLORO-12(METHYLSULFANYL) QUINOXALINE MOLECULE USING DFT". Journal of Advanced Scientific Research 13, n.º 04 (30 de abril de 2022): 51–58. http://dx.doi.org/10.55218/jasr.202213410.

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In this article theoretical DFT work on quinoxaline derivative is reported. Quantum mechanical calculations of different energies components of 11-Chloro-12(Methylsulfanyl) Quinoxaline [11Cl12MsQ] in ground state were carried out by DFT method, in isolated state and in different solvents to study the effects of solvents on various energy components. The influence of these solvents on optimized geometry, Mulliken charge distribution in ground and excited state were studied. With the help of computed highest occupied molecular orbital (HOMO) - lowest unoccupied molecular orbital (LUMO) gap of 11Cl12MsQ in different medium we can compute solvation energy, ionization potential, electron affinity, chemical hardness, electron chemical potential, electronegativity and global electrophilicity. UV-Vis spectrum and emission energy were analysed using TDDFT method. The density distribution analysis by total electron density (TED), potential distribution over molecule by electrostatic potential (ESP) positions of 11Cl12MsQ were analysed from molecular electrostatic potential (MEP) and frontier molecular orbitals (FMO) analysis. Thus, our objective is to determine their electronic, thermodynamic and spectroscopic parameters on the basis of the DFT quantum chemical analysis and also studying the effect of solvent and solute-solvent interactions. The structural, electronic and optical properties for quinoxaline derivative helps in better understanding of molecule in different medium which helps us to study biological properties of the molecule. This compound could be useful for designing of optoelectronic devices.

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Yim, C. T., e D. F. R. Gilson. "Orientation of some disk-shaped solutes in nematic liquid crystals". Canadian Journal of Chemistry 66, n.º 7 (1 de julho de 1988): 1749–51. http://dx.doi.org/10.1139/v88-281.

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The solute orientation parameters for benzene, trichloro-, and tribromobenzene have been measured, as functions of temperature, in the nematic solvents EBBA and ZLI-1132. The potential functions for orientation were derived for the model based on short and long-range contributions to the potential, with the former dependent on either a function of molecular shape or of molecular volume. There is reasonable agreement between calculated and experimental solute order parameters in both cases, and the difference in solute order parameter in the two solvents arises mainly from the difference in solvent electric field gradient.

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Azyat, Khalid, Darren Makeiff, Bradley Smith, Mickie Wiebe, Steve Launspach, Ashley Wagner, Marianna Kulka e Nicolas Godbert. "The Effect of Branched Alkyl Chain Length on the Properties of Supramolecular Organogels from Mono-N-Alkylated Primary Oxalamides". Gels 9, n.º 1 (22 de dezembro de 2022): 5. http://dx.doi.org/10.3390/gels9010005.

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Mono-N-alkylated primary oxalamide derivatives with different sized branched alkyl tail-groups were excellent low molecular weight gelators for a variety of different organic solvents with different polarities and hydrogen-bonding abilities. Solvent-gelator interactions were analyzed using Hansen solubility parameters, while 1H NMR and FTIR spectroscopy were used to probe the driving forces for the supramolecular gelation. The molecular structures of the twin tail-groups did not significantly affect the supramolecular gelation behavior in different solvents. However, for select solvents, the molecular structures of the tail-groups did have a significant effect on gel properties such as the critical gelator concentration, thermal stability, gel stiffness, gel strength, network morphology, and molecular packing. Finally, metabolic activity studies showed that the primary alkyl oxalamide gelators had no effect on the metabolic activity of mouse immune cells, which suggests that the compounds are not cytotoxic and are suitable for use in biomedical applications.

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Li, Xian-Zhi, Li Zhang e Keith Poole. "Role of the Multidrug Efflux Systems ofPseudomonas aeruginosa in Organic Solvent Tolerance". Journal of Bacteriology 180, n.º 11 (1 de junho de 1998): 2987–91. http://dx.doi.org/10.1128/jb.180.11.2987-2991.1998.

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ABSTRACT Multidrug efflux pumps with a broad substrate specificity make a major contribution to intrinsic and acquired multiple antibiotic resistance in Pseudomonas aeruginosa. Using genetically defined efflux pump mutants, we investigated the involvement of the three known efflux systems, MexA-MexB-OprM, MexC-MexD-OprJ, and MexE-MexF-OprN, in organic solvent tolerance in this organism. Our results showed that all three systems are capable of providing some level of tolerance to organic solvents such as n-hexane andp-xylene. Expression of MexAB-OprM was correlated with the highest levels of tolerance, and indeed, this efflux system was a major contributor to the intrinsic solvent tolerance of P. aeruginosa. Intrinsic organic solvent tolerance was compromised by a protonophore, indicating that it is substantially energy dependent. These data suggest that the efflux of organic solvents is a factor in the tolerance of P. aeruginosa to these compounds and that the multidrug efflux systems of this organism can accommodate organic solvents, as well as antibiotics.

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