Solvent Effects Research Articles

A New Proton Transfer Complex Between 3,4-Diaminopyridine Drug and 2,6-Dichloro-4-nitrophenol: Synthesis, Spectroscopic Characterization, DFT Studies, DNA Binding Analysis, and Antitumor Activity.

The proton transfer (PT) complexation reaction between 3,4-diaminopyridine (3,4-DAP), an important drug, and 2,6-dichloro-4-nitrphenole (DCNP) was investigated experimentally and theoretically. The experimental results indicated a chemical reaction occurred because of a hydrogen bonding, followed by proton transfer from the DCNP to the 3,4-DAP in different polar media. The Benesi-Hildebrand equation was used to estimate the formation constant (Kf), molar absorptivity (εPT), and other physical parameters. The formed PT complex was characterized using FTIR, 1H, and 13C NMR spectra. In addition, the nanocrystalline structure, particle sizes, and surface morphology of the complex were investigated by XRD and SEM-EDX. The structure of the 1:1 PT complex was calculated theoretically in the gas phase and the presence of solvent effects. Using TD-DFT calculations, the band observed at 406 nm (Calc. 379.5 nm) and 275 nm (Calc. 272.3 nm) could be assigned to the HOMO→LUMO transition (99%), and HOMO→L+3 transition (87%), respectively. The DNA binding ability of the PT complex was investigated, revealing an intercalative binding mechanism with a binding constant Kb of 4.6 × 104 M-1. Based on the results of the Ct-DNA binding study, the binding free energy of the PT complex with the receptor of human DNA (PDB ID:1BNA) is found to be -7.2 kcal/mol. The cytotoxic effects of the PT complex were evaluated on selected cancer cell lines, demonstrating significant antitumor activity against A-549 and MCF-7 cancer cell lines.

Experimental and simulation study of reverse micelles formed by aerosol-OT and water in non-polar solvents.

The formation of reverse micelles by aerosol-OT [sodium bis(2-ethylhexyl) sulfosuccinate] in hydrocarbon solvents, and in the presence of water, is studied using a combination of atomistic molecular-dynamics simulations and small-angle neutron scattering (SANS). There have been many previous studies of aerosol-OT and its self-assembly in both water and non-aqueous solvents, but this work is focused on a combined experimental and simulation study of reverse-micelle formation. The effects of hydration (with water-to-surfactant molar ratios in the range 0-60) and solvent (cyclohexane and n-dodecane) are investigated. A force field is adapted that results in spontaneous formation of reverse micelles starting from completely randomized configurations. The computed dimensions of the reverse micelles compare very favourably with those determined in SANS experiments, providing validation of the simulation model. The kinetics of reverse-micelle formation are studied with a 50-ns, 1.7-million-atom system which contains, in the steady state, about 50 reverse micelles. The internal structures of reverse micelles are characterized with mass density profiles, and the effects of solvent, and the structural crossover from highly structured water to 'bulk' water in the core, are detailed. The corresponding changes in the molecular reorientation times of sequestered water are also determined. Overall, the combination of experiment and simulation gives a detailed picture of reverse-micelle self-assembly and structure.

Solvent Effect on Cation⊗3π Interactions: A First-Principles Study.

Cation⊗3π interactions play a special role in the behaviors of biological molecules and carbon-based materials in aqueous solutions, yet the effects of solvation on these interactions remain poorly understood. This study examines the sequential attachment of water molecules to cation⊗3π systems (cation = Li⁺, Na⁺, K⁺), revealing that solvation influences interaction strengths in opposing ways: solvation of the metal cation decreases the strengths of cation⊗3π interactions, while the solvation of the benzene molecule increases the strengths of cation⊗3π interactions, compared with the strengths of cation⊗3π interactions in the gas phase. The mechanism analyses revealed that in the presence of surrounding water molecules, the stability of cation⊗3π systems is generally enhanced by cation-π, π-π, water-π, and water-ion interactions, while water-water interactions typically have a destabilizing effect. In addition, the primary effect of water molecules at different adsorption sites is to modulate the Coulombic multipole-multipole interactions and the overlap between monomeric charge distributions, thereby influencing the changes in strengths of cation⊗3π interactions. Moreover, AIMD simulations further underscore the practical significance of cation⊗3π interactions. These findings provide valuable insights into the structures and the strengths of cation⊗3π interactions with the effect of solvation.

Synthesis of furan-2-ones and spiro[furan-2,3ʹ-indoline] derivatives using polyether sulfone sulfamic acid catalysis

Polyether sulfone sulfamic acid (PES-NHSO3H) was prepared by simple sulfonation of a modified polyether sulfone. The number of acidic sites (SO3H) was determined to be 4.23 mmol H+/g by acid-base titration and 4.29 mmol H+/g by barium sulfate test. PES-NHSO3H was used as an efficient acidic catalytic system for the preparation of functionalized furan-2-ones and 2ʹ,5-dioxo-5 H-spiro[furan-2,3 ʹ -indoline]-3-carboxylate derivatives via the three-component reaction of anilines, aldehydes/1-ethylindoline-2,3-dione, and diethyl acetylene dicarboxylate in high yields (85–97%). The effect of polar and non-polar solvents on the productivity of the reaction was investigated. The catalyst was recovered 11 times without losses in catalytic potential.

The Fabrication of Lithium Niobate Nanostructures by Solvothermal Method for Photocatalysis Applications: A Comparative Study of the Effects of Solvents on Nanoparticle Properties

In this work, we report, for the first time, a comparative study on the effects of different solvents on the properties of LiNbO3 (LN) nanostructures. The solvothermal synthesis method was successfully used with three different solvents: 1—water, 2—methanol, and 3—benzyl. The structural and optical properties of the as-prepared nanoparticles were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis absorbance, Raman spectroscopy, and photoluminescence (PL). Nanoparticles of a very small size, with an average size between 3 and 10 nm, were obtained for the first time. The photocatalytic activities of the three synthesized LiNbO3 nanoparticles were studied in relation to the photodegradation of a complex and heavy reactive black 5 dye for a wastewater treatment application. The LiNbO3 synthesized with deionized water showed a higher photocatalytic activity than those synthesized using other solvents, such as methanol or benzyl.

Theoretical investigation on the surrounding effects of second-order nonlinear properties for (N^C^N)Pt(II)Cl complexes

Pt(II) complexes are widely used as nonlinear optical (NLO) materials. The geometric and electronic structures, second-order NLO property and UV–Vis absorption spectra of (N^C^N)Pt(II)Cl complexes (1–4) N^C^N binding by central benzene and two lateral N-heterocycles) are evaluated by density functional theory (DFT) and time-dependent DFT calculations. The detailed environmental effect of total first hyperpolarizability (βtot) in the solution and crystal phases is simulated by polarized continuum model (PCM) and quantum mechanics/molecular mechanics (QM/MM) method, respectively. The results highlight that the complex 3 exhibits largest βtot value in the gas, solution and crystal phases which can be attributed to the higher electron π-delocalization of ligands. Further, an evident red shift towards longer wavelength is observed for the complex 3. The origin of larger βtot value can be reasonably interpreted by the two-level model. In addition, the surrounding exerts an important influence on modulating second-order NLO properties. The solvent effect results in the larger βtot value than that of gas phase. The intermolecular interaction plays an important role in crystal phase. The formation of dimer can reduce the βtot value in comparison with the βtot value of the monomer in the crystal phase, because the centrosymmetric configuration of dimer implies a decrease of dipole moment (μ) in contrast to the large μ value of monomer. It is expected that this work will provide some guidance for designing Pt(II) NLO materials.

Molecular Simulation and Impact of Solvent‐Based Analysis of 2‐Methoxy‐4‐Allylphenol (Eugenol) Targeting Progesterone Receptor for Breast Cancer Therapy

ABSTRACTBreast cancer is a leading cause of cancer‐related morbidity and mortality among women globally. It arises from the abnormal proliferation of cells within breast tissue and can manifest in several subtypes, classified by the expression of hormone receptors. The main objective of this work is to assess the effect of solvent on 2‐methoxy‐4‐allylphenol's (2M4AP) in quantum chemical calculations and ability of 2M4AP to bind with the proteins associated with breast cancer. The non‐toxic nature of 2M4AP was initially validated through drug‐likeness studies and it complies with Lipinski's criteria. The optimization of 2M4AP structure was carried out in gas and liquid phase in DFT technique with B3LYP/6‐311++G (d, p) level. Then the electronic spectrum was calculated in TD‐DFT technique and the transition was determined to be n → σ*. The steadiness, charge dispersal and electronic properties were assessed and the band energy value was calculated to be 5.58 eV (gas) and 5.64 eV (liquid), exhibiting a stable confirmation of 2M4AP structure. Topological characteristics exhibited the intermolecular connections of 2M4AP along with electronic features. From the simulated results, the effect of solvent (water) in 2M4AP was very minimal and the structure is stable in both gas and liquid phase. Further, the docking studies, 2M4AP exhibited highest binding score of −7.3 kcal/mol with progesterone receptor, confirming the better ability of 2M4AP to react in hormone‐positive breast cancer. The Ramachandran plot confirms the stability of interacted amino acids with the ligand molecule. Thus, 2M4AP can be considered as a potent candidate for treatment of breast cancer after clinical studies.

DFT calculations of structural, chemical, electronic and thermodynamic properties of Rifampicin and Oxalic Acid

The thermodynamic properties of the compounds contribute to the theoretical analysis of the results of favorable energies that are subject to interaction. In this work, through the DFT study, the comparison of the functionals ωB97XD and B3LYP. Geometry optimization calculations and vibrational frequencies were performed for the individual ions and for the interactions. In all cases, all calculated vibrational frequencies are positive, confirming the optimized geometry obtained as a minimum on the potential energy surface. The calculations were carried out in solvent, considering the solvation effect in methanol using the IEFPCM (Integral Equation Formalism of the Polarizable Continuum Model) method. The present work aims to carry out a theoretical study, for in-depth investigations of structural, electronic and thermodynamic properties. In usability in the calculation of the thermodynamic properties, Rifampicin (RIF) and Oxalic Acid (OXA) and the interaction between RIF-OXA in the protonated form protonated RIF with charge +1 and deprotonated OXA with charge -1. In this context, the most favorable thermodynamic parameters in the interaction calculated RIF+-OXA- the values of ∆EZPVE+BSSE, ∆G298 and ∆H in kcal/mol more favorable are -19.62, -14.81 and -25,77.

Development of an efficient biocatalytic three-component reaction for synthesizing pyrrole derivatives

Multi-component reactions (MCRs) enable the development of efficient and atom-economic methods for synthesizing pyrrole derivatives. However, the current MCRs methods for synthesizing pyrrole derivatives in the enzymatic process have been unexploited. Herein, we developed a one-pot three-component enzymatic promiscuous catalytic system with green, efficient, and atom-economic to construct pyrrole derivatives. In this system, amines and 1,3-dicarbonyl compounds formed enamines with subsequent Michael addition with nitroolefins catalyzed by trypsin. A series of pyrrole derivatives were successfully obtained with moderate to good yield (up to 92 %). In addition, molecular simulations were conducted to gain insight into the source of differing tolerance of aromatic amides and fatty amines and the intrinsic effect of solvents in this system. This enzymatic catalytic one-pot three-component system has excellent functional tolerance, simple operation, and application potential for industrial production demonstrated by the gram scale experiment.

Effect of Solvents on the Performance and Structure of Polymethylacrylimide Aerogels.

Solvent effects play a critical role in solution polymerization, especially in free radical polymerization, where they influence both monomer-solvent interactions and the resulting polymer structure. In this study, polymethacrylimide (PMI) aerogels were synthesized via freeze-drying using dimethylformamide (DMF), dimethylacetamide (DMAc), and dimethyl sulfoxide (DMSO) as solvents. The effects of monomer reactivity ratios, monomer distribution, and solvent-monomer interactions on the shrinkage, bulk density, pore size, and compressive properties of the aerogels were investigated. Results demonstrated that solvent choice significantly impacted the polymerization process, leading to variations in the structure and properties of the final aerogels. Notably, aerogels synthesized in DMSO, the most polar solvent, exhibited the lowest shrinkage (33.98%), highest density (0.1582 g·cm-3), and highest compressive stress (1695.48 kPa at 70% strain). These findings underscore the importance of solvent selection in controlling the microstructure and enhancing the mechanical performance of PMI aerogels.

Kinetic investigation on palladium‐catalyzed carbonylation of allyl alcohol

AbstractPalladium‐catalyzed carbonylation of allyl alcohol to 3‐butenoic acid has been investigated. A significant effect of halide promoters, p‐tolylsulfonic acid (TsOH), water, solvents, and PPh3 concentration activity and selectivity has been studied. Detailed kinetics of this reaction was investigated in a temperature range of 363–383 K. The influence of parameters such as stirring speed, allyl alcohol, catalyst, benzyltriethylammonium chloride (BTEAC), TsOH concentrations, and CO partial pressures on the activity and selectivity has been studied. An empirical rate equation was suggested and found to be fairly consistent with observed rate data. In addition, the activation energy and kinetic parameters were evaluated.

Effect of Solvent and Cholesterol on Liposome Production by the Reverse-Phase Evaporation (RPE) Method.

Liposomal drug delivery is a promising approach for delivering therapeutics effectively. While most liposomes are designed to be nanometer-sized for efficient cellular uptake, micron-sized liposomes are gaining interest due to their larger drug-loading capacity. When combined with macroscale structures, such as implants and hydrogels, they offer prolonged therapeutic delivery. This study investigates how solvents affect the production of micron-sized liposomes, with or without cholesterol, using the reverse-phase evaporation (RPE) method. Although the RPE method is established for producing micron-sized liposomes, the influence of solvents on liposome size and uniformity is not well understood. The study explores whether controlling the size of inverse micelles, an intermediate product, through the use of different organic solvents affects the final liposome size. Three solvents─diethyl ether, methanol, and acetone─were tested for their effect on the formation of inverse micelles and liposomes and their sizes. Results showed that without cholesterol, diethyl ether produced uniform inverse micelles, leading to mostly nanosized liposomes. Methanol and acetone resulted in phase separation, preventing uniform liposome formation, although some micron-sized liposomes appeared. The acetone sample yielded mostly oil droplets. The results showed that forming inverse micelles lead to nanosized liposomes. With cholesterol, phase separation was dominant in methanol, but micron-sized liposomes still formed. Across all cases, cholesterol reduced the liposome size. The findings reveal that inverse micelles are not always reliable predictors of the final liposome size and that the RPE method is highly sensitive to solvent polarity and lipid-solvent interactions. Overall, the findings of this study provide valuable insights into how the choice of solvent and lipid composition can influence the production of liposomes via the RPE method. These insights are critical for optimizing liposome production and influencing future designs of liposomal drug delivery systems.

Reaction kinetics for catalytic hydrogenation of quinoline to decahydroquinoline as liquid organic hydrogen carrier

The catalytic hydrogenation of quinoline to decahydroquinoline (DHQ) formation is studied for various parameters such as temperature, hydrogen pressure, reaction time, solvents, reactant-to-solvent ratio, and catalyst loading over 5%Pd loaded on alumina (Pd/Al2O3) to obtain optimal reaction conditions. The hydrogen uptake of quinoline in the liquid phase reaction using isopropylalcohol (IPA) is studied in an autoclave reactor. The optimum reaction parameters of 50 bar H2 pressure and 175oC with reactant to solvent ratio of 1:9 for reaction time of 5 h are observed. The effect of IPA solvent showed that hydrogen uptake of 6.91 wt% with complete hydrogenation of quinoline and DHQ yield of more than 99% is observed. The reaction kinetic model is developed for a simplified reaction mechanism and is simulated using the Markov Chain Monte Carlo (MCMC) simulation tool to predict the rate constants and the experimental observations are validated with the model predictions. The activation energy for quinoline hydrogenation to py-THQ formation is estimated to be 136.57 kJ/mol. It is envisaged that quinoline hydrogenation to pz-THQ is the rate-limiting step in the DHQ formation.

Rational Control of Maximum EMI/CPL Intensity and Wavelength of Bora[6]helicene via Polarity and Vibronic Effects.

Solvent polarity control as an efficient methodology to regulate the chiroptical properties, including spectral shape, width, intensity, wavelength, etc., has emerged as a novel frontier in optical materials design. However, the underling relationship connecting polarity to the optical property remains unclear. Herein, using state-of-the-art computations and the FC|VG model, the solvent effect on the chiroptical properties of bora[6]helicene was accurately and systematically computed to shed light on this issue. It is found that the vibronic coupling is crucial in explaining the spectral shape, width, and relative intensity of different peaks. Moreover, the intensity and position of the emission (EMI) and circularly polarized luminescence (CPL) are closely related to the polarity of the solvent. Intriguingly, we got a series of good linear relationships between polarity and EMI|CPL (|r| ≥ 0.95). Thus, this parameter can be used as a potential descriptor to estimate the intensity and position of EMI|CPL, leading to new strategies for designing fully colored fluorescent materials.

Solubility of letrozole in eight pure and five mixed solvents: Measurement, thermodynamic and molecular simulation analysis

In this work, the solubility of letrozole within eight single and five binary solvents was first systematically investigated at 283.15 K to 323.15 K via the gravimetric method. Subsequently, four thermodynamics formulas including modified Apelblat, λh, GSM and Jouyban-Acree were utilized to link the experimental outcomes of letrozole, all models achieved the good fitting performance and the ARD% was less than 2 %. The dissolvability of letrozole in chosen solvents exhibited a positive correlation with temperature, and co-solvency was observed in such mixed solvent systems as ethyl acetate + 1-propanol, and acetonitrile + 1-propanol. Furthermore, the sites of hydrogen bonding donor and acceptor of letrozole and solvents were analyzed through the molecular electrostatic potential surfaces (MEPs). Then solvent effect, solvation free energy and radial distribution function (RDF) analysis gained via molecular simulation were utilized to illuminate experimental phenomena, the outcomes manifested the polarity, cohesive energy density and other properties of solvents along with both solvent–solvent and solute–solvent interactions contributed differently to the dissolution processes. In the end, the apparent thermodynamic identities concerning letrozole within chosen solvent systems were computed under the van’t Hoff and Gibbs formulas, and outcomes showed that dissolution concerning letrozole was a procedure of endothermic and entropy mainly driven.

The Stability Challenge of Furanic Platform Chemicals in Acidic and Basic Conditions.

The transition toward renewable resources is pivotal for the sustainability of the chemical industry, making the exploration of biobased furanic platform chemicals derived from plant biomass of paramount importance. These compounds, promising alternatives to petroleum-derived aromatics, face challenges in terms of stability under synthetic conditions, limiting their practical application in the fuel, chemical, and pharmaceutical sectors. Our study presents a comprehensive evaluation of the stability of furan derivatives in various solvents and under different conditions, addressing the significant challenge of their instability. Through systematic experiments involving GC‒MS, NMR, FT‒IR and SEM analyses, we identified key degradation pathways and conditions that either promote stability or lead to undesirable degradation products. These findings demonstrate the strong stabilizing effect of polar aprotic solvents, especially DMF, and reveal the dependence of furan stability on solvent and additive type. This research opens new avenues in the utilization of renewable furans by providing critical insights into their behavior under synthetic conditions, significantly impacting the development of sustainable materials and processes. The broad appeal of this study lies in its potential to guide the selection of conditions for the efficient and sustainable synthesis of furan-based chemicals, marking a significant advance in green chemistry and materials science.

Weak solvation effects and molecular-rich layers induced water-poor Helmholtz layers boost highly stable Zn anode

The advancement of aqueous Zn-based energy storage systems encounters major challenges due to the occurrence of side reactions and the growth of dendrites caused by the highly active nature of water in the aqueous electrolyte. Herein, a zwitterion additive named sulfonated amphoteric betaine (referred to as DMAPS) regulates the Zn2+ electrolyte environment through a weak solvation effect to promote highly stable Zn anodes. The inherently occurring anionic (-SO3-) and cationic (-NR4+) counterions in the DMAPS chain can be effectively separated under an external electric field to enable the creation of distinct ion migration pathways, thereby significantly enhancing the transportation of electrolyte ions. Moreover, DMAPS can be adsorbed onto the surface of Zn anode to form a H2O-poor Helmholtz layer, which can serve as a protective barrier to suppress corrosion of the Zn anode by free H2O and inhibits the formation of differential electric field to facilitate the directional deposition of Zn2+. In addition, density functional theory (DFT) and molecular dynamics (MD) further assisted in demonstrating the intrinsic mechanism of the reconstruction of the solvated sheath structure of Zn2+ by DMAPS. As a result, the Zn//Zn symmetric cell in ZnSO4+DMAPS solution can be cycled steadily for 2100 h at a current density of 1 mA cm-2 and 1 mAh cm-2. The assembled Zn ion hybrid capacitor with ZnSO4+DMAPS electrolyte was stably cycled for 20,000 cycles with 90% capacity retention at 5 A g-1.

High‐Efficiency Deep‐Blue Solution‐Processed Organic Light‐Emitting Diodes Using Carbazole Dendrons Modified Hybridized Local and Charge‐Transfer Emitters

In the pursuit of efficient and cost‐effective organic light‐emitting diodes (OLEDs), the development of solution‐processed hybridized local and charge transfer (HLCT) emitters presents a promising approach. HLCT materials uniquely integrate the advantages of both singlet and triplet excitons, surpassing the traditional spin statistical limit of 25% while offering high photoluminescence efficiency and balanced charge transport properties. Herein, we report the synthesis and characterization of two new deep blue, solution‐processable HLCT fluorophores, G1FTPI and G2FTPI. These compounds incorporate fluorenyl carbazole dendron units into the HLCT luminogenic triphenylamine‐phenanthroimidazole (TPI) molecule. Their HLCT and photoluminescence (PL) properties were experimentally and theoretically investigated using solvation effects and density functional theory (DFT) calculations. The molecules exhibit deep blue emission with a high solid‐state fluorescence quantum yield, good solution‐processed film‐forming quality, and high hole mobility values of 2.18 – 2.61 × 10‐6 cm2 V‐1s‐1. Both compounds were successfully employed as non‐doped emissive layers in solution‐processed OLEDs, demonstrating excellent electroluminescent (EL) performance. Notably, the G2FTPI‐based device emitted a deep blue light at 432 nm with CIE coordinates of (0.158, 0.098) and achieved a a maximum current efficiency (CEmax) of 3.13 cd A‐1 and a maximum external quantum efficiency (EQEmax) of 5.30%.

Copper‐Catalyzed Chemoselective Synthesis of Pyrazolo‐Sulfonamide: Impact of Solvent on Nitro‐pyrazole Reactivity

Abstract: This study presents a copper‐catalyzed, solvent‐dependent method for the rapid and efficient synthesis of N‐pyrazolo‐sulfonamides directly from nitro‐pyrazole and sulfonyl hydrazide under microwave conditions. The reaction exhibits notable solvent effects in pyrazole’s reactivity. The ionic liquid DBU‐AcOH triggered the reactivity of 4‐nitro‐pyrazole, whereas the reaction in PEG proceeded selectively at the 3‐ & 5‐positions of pyrazole. Key applications of this method include the gram‐scale synthesis of pyrazolo‐sulfonamide, sulfaphenazole analogue and sulfonamide

Extraction solvents effect on asphalt binder properties

Asphalt industries are actively pursuing the integration of recycled asphalt pavement (RAP) into their constructions to promote sustainable pavement solutions amidst resource scarcity. However, challenges persist in the extraction and recovery processes, potentially affecting asphalt pavement performance assessments. This study investigates the impact of three common solvents—n-propyl bromide (nPB), trichloroethylene (TCE), and a toluene-ethanol blend (85 %/15 %)—on the rheological properties of recovered binders, particularly aiming to identify a substitute for TCE in light of its proposed ban by the Environmental Protection Agency (EPA) in the USA. Tests were conducted on six different performance-graded (PG) binders from diverse sources, assessing high-temperature properties using Dynamic Shear Rheometer (DSR) and Multiple Stress Creep Recovery (MSCR) tests, as well as low-temperature properties via Bending Beam Rheometer (BBR). Fourier Transform Infrared (FTIR) spectroscopy confirmed the absence of solvents in the recovered binders. Although minor variations were observed in measured properties between original and recovered binders due to solvent use, these differences did not affect the resulting performance grades. Thus, the toluene-ethanol blend can potentially substitute for TCE. However, it is noteworthy that the toluene-ethanol blend (85 %/15 %) displayed a slower solubility rate compared to nPB and TCE, underscoring the need for caution in its usage.