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Ratiometric optical detection of analytes is a convenient strategy as the technique is devoid of relative error and background correction. Herein, solvent‐guided ratiometric optical recognition of fluoride and bisulfate anions by a low‐cost, "off‐the‐shelf" bioactive molecule, harmane (HRH) is thoroughly explored. Interestingly, solvent plays a dynamic role in the selective recognition of the dual anions via the dual channels of HRH in an intelligent manner. The probe displays high‐fidelity recognition behavior towards fluoride ion in an aprotic solvent (acetonitrile) and towards bisulfate ion in a protic environment (acetonitrile/water; 5:1; v/v). Both the channels of HRH are very selective for a particular anion (F−/HSO4−) in a specific solvent. Organized and comprehensive theoretical calculation denotes that hydrogen bonding between the acidic pyrrolic proton of HRH and fluoride for the first channel and the acidic proton of bisulfate and the pyridinic nitrogen for the second channel of HRH led to the formation of a hydrogen‐bonded ion pair (HBIP). Consequently, significant optical changes are observed in the visible region, which is convenient for real‐life detection of F− and HSO4− independently. The essential role of solvent in tuning the dual channels of HRH is an important artifact in the literature of fundamental photochemistry. [ABSTRACT FROM AUTHOR]

As a new molecular scaffold of photoswitchable fluorophore, we developed a photochromic diarylethene containing a betaine structure based on pyridinium N‐enolate. A facile reaction of a pyridyl‐substituted dithienylperfluorocyclopentene derivative with octafluorocyclopentene constructed the betaine structure. The introduction of the betaine moiety provided the diarylethene molecule with bathochromically shifted optical absorption and fluorescing ability, thus enabling the molecule to function as a visible‐light‐responsive turn‐off mode photoswitchable fluorophore. The molecule in the open‐ring form emitted bright bluish green fluorescence. Upon irradiation with 405 nm light, the molecule underwent cyclization isomerization to form the closed‐ring isomer and the fluorescence intensity significantly decreased. The turn‐off mode fluorescence photoswitching was observed not only in solution but also in polymer films. [ABSTRACT FROM AUTHOR]

The effect of solvents on kinetic parameters of anionic polymerization is complex and a comprehensive theoretical study has been rare. In this work, four solvent polarity descriptors (i.e., polarizability, dipole moment, nucleophilic index, electrophilic index) are correlated with solvent parameters (Ea, A, ΔH‡, and ΔS‡) by multiple linear regression using the Catalan linear free‐energy relationship (LFER) equation for the anionic polymerization of styrene. The results show that Ea, ΔH‡, and ΔS‡ have a low correlation with dipole moment, whereas A is strongly correlated with dipole moment. Given the fact that the larger A the larger effective collision frequency Z, it is hypothesized that in polar solvents, the polymer chains are more extended, enabling more effective collisions between monomers and active anionic species during polymerization. In contrast, in nonpolar solvents, the polymer chains collapse, making it more difficult for the monomer to be inserted into the ion pairs. Subsequently, n‐pentane and tetrahydrofuran are chosen as representatives to confirm this conjecture by molecular simulations. Lastly, Ea, A and kp are predicted for 173 solvents using well‐established descriptive relationships. [ABSTRACT FROM AUTHOR]

The infrared absorption spectrum of coumarin C545T was studied by quantum chemical calculation and experiments. Based on quantum chemical density function theory, the optimized structural parameters, the infrared spectra of C545T and its solvent effect were calculated at the B3LYP/6-31G (d) level. The infrared absorption spectra of C545T power and C545T saturated solutions with different solvents were also measured by Fourier transform infrared spectrometer. The calculated results are in good agreement with the experiments, with a linear regression correlation coefficient of 0. 9996. In addition, the infrared spectrum of C545T exhibits solvent effect.Taking C = 0 for an example, its vibration frequency decreases with the increase of the solvent polarity, namely bathochromic shift. The experimental vibration frequency of C=O chemical bond is linearly related to the dielectric constant of the solvent. [ABSTRACT FROM AUTHOR]

Research on solvent effects is an important and long-standing topic, but there still is some room, especially for the special solvent effect of fluoroalcohols. In this work, we investigated the stability of phenoxyl radical in monohydric alcohol solvents through in-situ electron paramagnetic resonance detections. The decay behavior of phenoxyl radical showed a reasonable relationship with the mesoscopic structure of alcohols, characterized by smalland wide-angle X-ray scattering. Moreover, the distinct solvent effects of fluoroalcohols were emphasized, and the significant influence of van der Waals distance in the solvents was suggested. Overall, the stability of phenoxyl radical in alcohols was quantified and correlated with the solvent structures. We believe that the established method for stability study on radicals will encourage solvent effect studies on various organic reactions, and the proposed solvent effects in fluoroalcohols may inspire the development of green solvents in both industrial conversions and organic synthesis. [ABSTRACT FROM AUTHOR]

ABSTRACT A salamo‐type bis‐oxime ligand H2L was synthesized, which reacted with Ni (NO3)2·6H2O in different reaction solvents to synthesize two novel heptanuclear Ni (II) complexes: [Ni7(L)3(μ3‐OH)8(EtOH)6]·2CH2Cl2 (1) and [Ni7(L)3(μ3‐OMe)2(μ3‐OH)6(MeOH)6]·CH2Cl2 (2). X‐ray crystal diffraction results showed that each Ni (II) ion exhibits a distorted octahedral geometry. Its uniqueness lies in the fact that the Ni (II) ion in Complex 1 not only coordinates with ligand units but also coordinates with ethanol solvent molecules and water molecules participating in bridging. Complex 2 is composed of water molecules and methanol molecules connected together. Interestingly, the coordination mode is different due to the different reaction solvents. The energy gap changes of the ligand, and its complexes were then explored by DFT calculations. In addition, the influence of the weak interaction force was confirmed through the in‐depth study of electrostatic potential, IRI, freedom analysis, and Hirshfeld surfaces analyses, which is important for explaining the formation of reaction sites and supramolecular structures. UV‐visible spectrometric titration tests showed that the binding ratios of the ligand to Ni (II) ions are all 3:7, which is consistent with the crystal structure. Finally, fluorescence characterization studies showed that both complexes exhibited reduced fluorescence compared to H2L. [ABSTRACT FROM AUTHOR]

ABSTRACT A salamo‐type biscompartmental ligand was successfully prepared. On this basis, two novel pentanuclear zinc (II) salamo‐type complexes possessing solvent effect were self‐assembled successfully with different zinc (II) salts: [Zn5(L)2(μ‐OAc)2(CH3COCH3)] (1) and [Zn5(L)2(μ‐OAc)2(CH3CN)] (2). Complex 1 contains two fully deprotonated (L)4− units, five Zn(II) atoms, two coordinating acetate anions, and one coordinating acetone molecule. The zinc (II) atoms are all in a slightly distorted triangular bipyramidal geometrical configurations. Complex 2 consists of two fully deprotonated (L)4− units, five zinc (II) atoms, two coordinating acetate anions and a coordinating acetonitrile molecule. The different structures of the self‐assembling complexes may be attributed to various solvent effects applied in the self‐assembly. As a result, the acetate anions are involved in bridging coordination, thereby expanding the distance between secondary building units (SBUs). In addition, polar nonprotonic solvents, especially acetonitrile and acetone molecules, were involved in the coordination process. Finally, the reaction sites and intermolecular interactions were further discussed by MEP, IRI, and Hirshfeld surfaces, and their fluorescence properties were explored. [ABSTRACT FROM AUTHOR]

Low‐dimensional metal halides (LDMHs) represent a promising class of materials in various luminescent applications because of their self‐trapped exciton (STE) emissions with unique properties such as broad luminescence spectra, large Stokes shift, and high color rendition. LDMHs at the molecular level can be constructed, including 2D layers, 1D chains, and 0D clusters assembled by polyhedra units, all of which exhibit significantly different luminescence properties from 3D MHs. The dimensional regulation of LDMHs has been explored for years, including the choice of organic cations, modulating electron‐phonon coupling effect, and adding external temperature and pressure. Herein, this review discusses the synergy between structural engineering and solvent effects for LDMHs, including the emission mechanisms for LDMHs and the roles solvent molecules play in regulating the dimensions. In addition, challenges and opportunities for LDMHs are discussed to shed light on the future development of novel materials with multifunctional optical properties suitable for practical applications. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In recent decades, sulfur-containing compounds have played a significant role in biological applications because of their unique biological and chemical characteristics. Taurolidine, a sulfur-containing derivative of the amino acid taurine, has been characterized theoretically utilizing Density Functional Theory (DFT) at the B3LYP approach along with a 6-311++G(d,p) basis set. The impact of solvents on electronic characteristics, Molecular electrostatic potential (MEP), and Fourier Molecular Orbital (FMO) in polar (water and ethanol) and nonpolar (toluene and chloroform) has been analyzed. The bond distances of S1-C16 and S1-C17 have been simulated at 1.817 Å and observed at 1.743 and 1.739 Å, respectively. These distances are increased compared to other bond distances due to the influence of sulfur atoms. The distinctive simulated vibrational wavenumbers of taurolidine revealed peaks for SO2, CH2, CN, and NH groups. The intramolecular interactions responsible for stabilizing the molecular structure of taurolidine have been addressed using NBO analysis shows significant stabilization energy from electron-donating lone pair oxygen O6 to antibonding S2-N10 with the stabilizing energy of 19.88 KJ/mol by the transition of LP(3)-s*. The bonding characteristics and reactive sites (electron-rich and electron-poor) have been confirmed with Mulliken and MEP analysis. The carbons (C17 and C16) emphasize the increased negative potential due to the sulfonyl (SO2) group in the ortho position. The topological insights, ELF and LOL, were spotted using Multiwfn software, highlighting the localized and delocalized electron regions within the crystal structure. In addition, molecular docking was performed to predict the antagonist activity of taurolidine against ß-catenin protein, yielding a binding energy of -6.86 KJ/mol, which confirms its antiproliferative property. [ABSTRACT FROM AUTHOR]

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FmocFF (9-fluorenyl methoxycarbonyl-phenylalanine) is an extensively studied low-molecular-weight hydrogel. Although there have been numerous studies on FmocFF hydrogel, its potential to form organogels has not been well explored. In this work, we systematically explore the organogels of FmocFF in a wide range of organic solvents. FmocFF is found to be a robust organogeltor, and the subsequent organogels exhibit diverse gelmorphic behavior exhibiting various degrees of crystallinity and morphology depending on the solvent used. The mechanical strength of the organogels is evaluated using rheology. A novel technique, in situ SHG microscopy, is introduced to study the gel structure in its native state. In addition to the solvent–solute interactions that are typically used to predict gelmorphic behavior, we observed indications that the degree of crystallinity also plays a significant role in determining the mechanical properties and structure of FmocFF organogels. [ABSTRACT FROM AUTHOR]

The problem of whether and how the captodative aromatic systems with the donor and acceptor substituents at the same carbon atom of the C=C bond can be more stable than the π‐conjugated push‐pull counterparts with the two substituents in the vicinal position is analyzed for cyclopentadienyl derivatives possessing an aromatic cyclopentadienyl ring. The analysis of electronic, magnetic, and structural criteria of aromaticity showed that among typical organic donors, such as amines NR3, ethers R2O, guanidine (NH2)2C=NH, siloxane O(SiH3)2, silatrane, the captodative isomers [cyclopentadienylium]−C(X+) = CH2 can be more stable than their push‐pull isomeric counterparts [cyclopentadienylium]−—CH=CH—X+. The largest energy difference in favor of the former was found to be ca. 13 kcal/mol for X = NH=C(NH2)2. [ABSTRACT FROM AUTHOR]

This study explores the potential mechanisms (Paths 1 and 2) involved in the regioselective dipolar cycloaddition of thioamides, selenoamides, and amides with propargyl alcohol using density functional theory (DFT). Our calculations reveal that the initial step involves the formation of a cation with catalyst. Subsequently, isomerization occurs between cations I and II via 1,3‐hydride transfer in the second step. We analyzed the global reactivity index and frontier molecular orbital (FMO) theory to gain insights into the mechanism. In the third step, chalcoamides attack cations I and II, forming an intermediate. The formation of a five‐member ring intermediate constitutes the fourth step, followed by hydrogen transfer to produce stable five‐member heterazole compounds in the final step. We demonstrated the influence of substituents in the electrophile by employing various electron‐withdrawing and donating groups. Additionally, we examined the effect of the dielectric medium on the reaction barrier using polarizable continuum model. Thus, this study provides valuable insights for the rational design of more efficient 1,3‐dipolar cycloaddition reactions yielding regioselective products. [ABSTRACT FROM AUTHOR]

Copper(II) chloride anionic coordination complexes with different imidazole‐derived ligands due to the potential cytotoxic activity play the important role in protein. By investigating the experimental electron paramagnetic resonance (EPR) and ultraviolet–visible (UV–vis) spectra of [CuCl(C6H10N2)4]Cl, [CuCl(C6H10N2)4]Cl, [CuCl2(C4H6N2)4], and [Cu2Cl2(C5H8N2)6]Cl2·2H2O, the local structure of the corresponding Cu2+ centers and the role of different ligands are obtained. Based on the well‐agreed EPR parameters and the d‐d transitions (10Dq), the four Cu2+ centers show tetragonal and orthorhombic distortion, corresponding to the different anisotropies of EPR signals. In addition, the general rules of governing the impact of methanol in imidazolylalkyl derivatives are also discussed, especially the influence on the local environment (symmetry, distortion, covalency, and crystal field) of above four copper(II) chloride anionic coordination complexes. Therefore, the obtained results in this study will be beneficial to provide a theoretical basis for the experimental design of desired copper‐containing imidazolyl alkyl derivatives. [ABSTRACT FROM AUTHOR]

Calcium carbide (CaC2) is a valuable carbanion resource, but the reactivity is highly restricted by its insolubility and super‐basicity. For this, the effect of solvent and mechanical forces on its reactivity is investigated extensively here via quantum chemistry calculation, molecular dynamic simulation, and experiments. The dissolution free energy of CaC2 in over 100 solvents has been evaluated. DMSO, CH3CN, and DMF can enhance the negative potential and reactivity of CaC2, especially DMSO. The electrostatic interaction of CaC2‐solvent mainly originates from the interaction between Ca2+ and O or N atom. The increased electron density around C22‐ is mainly ascribed to the electron transfer from solvent. DMSO can change the ionic orientation of CaC2 interface. The solvent may be deprotonated by C22‐, compromising the solvent stability. The interface interaction of CaC2 with DMF and DMSO is verified through FT‐IR, and the lattice structure of CaC2 is lost virtually after 0.5 h mechanical milling. [ABSTRACT FROM AUTHOR]

In this study, effects of 4 solvents (petroleum-ether, n-hexane, ethyl-acetate, and chloroform) on the chemical characterizations and in vitro antioxidant capacities of oil were assessed to determine the optimal extraction solvent for L. edodes oil. Three data analysis techniques including principal component analysis, hierarchical cluster analysis, and multiple linear regression, were applied to determine the relationship between the nutrient and antioxidant capacity. The results showed that chloroform extracted L. edodes oil exhibited the largest amount of a-tocopherol, flavones, and unsaponifiable matter, chloroform was thus confirmed desirable for extracting L. edodes oil rich in nutrition. While based on the best DPPH and ABTS, the ethyl-acetate extracted oil show the strongest antioxidant property. More than that, the results also showed that different extraction solvents could induce large variations in minor components and free radical scavenging activity among the test oils, and the total phenol content was found positively correlated to the antioxidant capacity of L. edodes oil, which could be well predicted by all MLR models. These findings revealed the influence of solvent on the chemical characterization and in vitro antioxidant capacity of L. edodes oil, providing a theoretical foundation for future applications of L. edodes oil. [ABSTRACT FROM AUTHOR]

Despite various efforts to optimize the near‐infrared (NIR) performance of perylene diimide (PDI) derivatives for bio‐imaging, convenient and efficient strategies to amplify the fluorescence of PDI derivatives in biological environment and the intrinsic mechanism studies are still lacking. Herein, we propose an alkyl‐doping strategy to amplify the fluorescence of PDI derivative‐based nanoparticles for improved NIR fluorescence imaging. The developed PDI derivative, OPE‐PDI, shows much brighter in n‐Hexane (HE) compared with that in other organic media, and the excited state dynamics investigation experimentally elucidates the solvent effect‐induced suppression of intermolecular energy transfer and intramolecular nonradiative decay as the underlying mechanism for the fluorescence improvement. Theoretical calculations reveal the lowest reorganization energies of OPE‐PDI in HE among various solvents, indicating the effectively suppressed conformational relaxation to support the strongest radiative decay. Inspired by this, an alkyl atmosphere mimicking HE is constructed by incorporating the octadecane into OPE‐PDI‐based nanoparticles, permitting up to 3‐fold fluorescence improvement compared with the counterpart nanoparticles. Owing to the merits of high brightness, anti‐photobleaching, and low biotoxicity for the optimal nanoparticles, they have been employed for probing and long‐term monitoring of tumor. This work highlights a facile strategy for the fluorescence enhancement of PDI derivative‐based nanoparticles. [ABSTRACT FROM AUTHOR]

Schizophyllan is a triple helical β‐1,3‐D‐glucan, and shows the cooperative order–disorder transition in the aqueous solution at the triple helix state. In this paper, the solvent stabilizing effects of two carboxylic acids, acetic acid and citric acid, on the cooperative order–disorder transition of aqueous schizophyllan solution were investigated from DSC and SEC‐MALS measurements. The transition temperature (Tr) was shifted to higher temperature with increasing the molar fraction of carboxylic acid in the mixture (x). The transition enthalpy (ΔHr) was increased with increasing x. These solvent stabilizing effects indicate that these carboxylic acid molecules were selectively associated with the branched side chains of schizophyllan to stabilize the ordered state. The composition dependencies of Tr and ΔHr were analyzed by the linear cooperative transition theory to estimate the association parameters between the side chains and carboxylic acid. The theoretical parameters obtained were compared with those for the other active substances for the transition to discuss the molecular interactions between the triple helix and carboxylic acid. [ABSTRACT FROM AUTHOR]

The effect of the external electric field on the ground-state tautomerism in 8-(benzo[d]thiazol-2-yl)quinolin-7-ol has been studied by using density functional theory. The compound exists as an enol tautomer (off state) and under the influence of the external electric field a long-range intramolecular proton transfer can occur, placing the tautomeric proton at the quinolyl nitrogen atom (on state). This is a result of the much higher dipole moment of the end keto tautomer and indicates that the external electric field can be used to mimic the implicit solvent effect in tautomeric systems. In the excited state, the further stabilization of the most polar on state leads to a situation when the excited-state intramolecular proton transfer becomes impossible, limiting the intramolecular rotation to the conical intersection region. [ABSTRACT FROM AUTHOR]

Context: The cyclopropane skeleton plays a significant role in bioactive molecules due to its distinctive structural properties. This has sparked keen interest and in-depth exploration in the field of stereoselective synthesis of cyclopropane derivatives. In the present study, the mechanism and the origin of stereoselectivity of diastereodivergent synthesis of cyclopropane derivatives via the catalyst-free [2 + 1]-cyclopropanation reactions of 3-diazo-N-methylindole (R1) with two types of electron-deficient olefins (R2 and R3) in both aqueous and toluene media have been studied using the DFT calculations. The findings indicate that these [2 + 1] cycloaddition reactions proceed in two stages, where the first step is not only the rate-determining step but also critically dictates the stereoselectivity of the product. The calculated diastereomeric ratios are in agreement with the experimental results. Furthermore, by utilizing non-covalent interaction (NCI) analysis and energy decomposition analysis based on molecular force fields (EDA-FF), we elucidated that the electrostatic interactions between reactant fragments in the transition state TS1s for the first step are the predominant factors determining the stereoselectivity, as opposed to the experimentally hypothesized steric hindrance and π-π stacking interactions. Methods: The geometrical structures of all minima and transition states on the potential energy surface (PES) in solvents water and toluene were fully optimized using the DFT method at the M06-2X(D3)/SMD/6–31 + G(d,p) level of theory. Single-point energy calculations were carried out based on the optimized geometries in the solution at the M06-2X(D3)/6–311 + G(d,p) level. All the DFT calculations were performed using the Gaussian 09 software. The optimized molecular structures were visualized using CYLview software. NCI analysis was performed using the Multiwfn and VMD softwares. The Multiwfn program was also used for CDFT and EDA-FF analyses. [ABSTRACT FROM AUTHOR]

B3LYP/cc-pVDZ generated the best N-(5-((4-ethylpiperazin-1-yl)methyl)pyridin-2-yl)-5-fluoro-4-(4-fluoro-1-isopropyl-2-methyl-1H-benzo[d] imidazol-6-yl) pyrimidin-2-amine (TA) results. The NBO study shows that the LP (1) N16 to π*(C17-N19) has the highest stabilization energy at 53.86 kcal/mol. Electron localization and delocalization areas are confirmed by wavefunction studies. The Gaussian-16w software establishes thermodynamic properties for a titled compound which is confirmed by various solvents. The frontier molecular orbital studies we confirmed by gas phase have the highest bond gap value which is 4.02 eV. The titled compound nitrogen is the nucleophilic attack (blue color) and oxygen is the electrophilic attack (red color), which is confirmed by MEP study. In non-linear optical (NLO) study water solvent shows the highest dipole moment activity, due to the solvent's interaction the gas phase dipole moment is lower. The docking study showed the greatest binding affinity score of −5.28 kcal/mol. [ABSTRACT FROM AUTHOR]

The B3LYP/cc-pVDZ basis set was used to optimize the best results of Pacritinib whose systematic name is (E)- 44-(2-(pyrrolidin-1-yl) ethoxy) −6,11- dioxa-3- aza-2(4,2)- pyrimidine −1,4 (1,3)-dibenzenacyclododecaphan-8-ene (MJ). The NBO analysis confirm the highest stabilization energy 55.36 kcal/mol, from bonding LP (1)–N13 to anti-bonding π*(N10 - C11). The ELF, LOL, ALIE, and RDG, analysis was done by using Multiwfn software, and confirms the localization and delocalization electrons. The thermodynamical properties and electron density were calculated with help of Gaussian-16w software. Analyses of NLO parameters, MEP, UV-vis, and HOMO-LUMO were performed using five different solvents (chloroform, water, acetonitrile, ethanol and DMSO). Docking study was done, against 5C5S protein and we identify the protein-ligand interaction, the best binding score is −6.64 kcal/mol. [ABSTRACT FROM AUTHOR]

In this research project, a computational assessment of the molecular structure of Ipriflavone (IP) in the gaseous phase was done based on density functional theory (DFT). In the realm of theory, the standard basis set B3LYP is a collection of functions used with linear combinations to produce molecular orbitals, making it simple to compute the molecular structure related to the given compound. With the time-dependent DFT approach, the UV spectra obtained for various solvents were used for examining the electronic transport features. A three-dimensional representation of the molecules that shows the charge distributions and charge-related characteristics of the molecule has the acronym the electrostatic potential map. The frontier molecular orbitals (FMO) confirmed the compound's stability and good reactivity. Hyperpolarizability calculations were performed with good non-linear optical (NLO) potent. Natural bond orbital (NBO) analysis was used to explore charge delocalization and the compound's stability. Topological investigations have been identified to clarify the bonding zones, weakest contacts, and electron energy density. Drug likeness studies were used to promote bioactivities. The outcome of docking tests shows that the ligand under investigation is beneficial at preventing bone loss-osteoporosis. To sum up, this work provides a comprehensive analysis that combines spectroscopic and quantum computational techniques to assess the effect of specific medicinal compounds on solvation and metabolic activity. Strategies for subsequent studies can thus greatly benefit from the knowledge obtained. [ABSTRACT FROM AUTHOR]

Metal–organic framework (MOF) membranes are widely used in gas separation processes. However, the effect of solvents on the formation of large‐area MOF membranes, which directly influences separation performance, has rarely been investigated. In this study, three solvents (methanol, ethanol, and water) were selected to systematically investigate their effects on the zeolite imidazolium frameworks (ZIF) membrane formation via experimental validation and simulations. The results indicated that the solvent selection influenced crystallization rate, crystal size, and ZIF‐8 membrane formation ability. Particularly, when water was used as a solvent, slow nucleation and crystallization of the ZIF‐8 crystals were observed, resulting in a more complete crystal structure and a thinner ZIF‐8 membrane. Therefore, the ZIF‐8 membrane exhibited a gas permeance of 10,000 gas permeation unit and enhanced CO2/N2 selectivity. Furthermore, ZIF‐8 membrane with a surface area of 2400 cm2 and spiral‐wound membrane modules were developed, paving the way for large‐scale industrial production. [ABSTRACT FROM AUTHOR]

The effect of storage time and solvent on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical stability was studied using electron spin resonance. Tetrahydrofuran affected the g-factor due to a rearrangement within the DPPH structure that changed the radical centre. There was also a change in the spins concentration when modifying the solvent and storage times. The more than 96 % decrease in spins after 12 weeks, consistent with a change in the pH and color, was attributed to the electron- and hydrogen-donor capabilities of the solvents, leading to a shift among the different DPPH ionic states. Tetralin instantly interacted with the DPPH capping many radicals.

The synergistic effect of an alcohol solvent and microwave irradiation dramatically increased the C–N coupling rate, enabling the rapid synthesis of N -sulfonyl ynamides in ten minutes. The optimal catalyst, ligand, and solvent combination was investigated, and various bromoalkynes and sulfonamides were shown to be tolerated under these conditions. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

Solvent effects add a new dimension for tuning the activity and selectivity of heterogeneous catalytic reactions, which is extensively employed in the hydrogenation of unsaturated compounds with multiple functional groups. In this concept, we briefly summarize recent developments on how the solvent effects affect the catalytic performance from the following aspects: 1) the polarity of the solvent can influence the interaction between the solvent and the reactant or intermediate; 2) the composition of mixed solvent can influence the reactivity of the reactant or intermediate; 3) solvent effect varies with the metal identity and support; 4) the solvent can induce surface modification of the supported catalysts. This summarization will provide insights into the rational development of efficient and selective heterogeneous hydrogenation catalytic system to realize the precise synthesis of desired chemicals. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

Vapor‐phase propylene (C3H6) epoxidation kinetics with hydrogen peroxide (H2O2) strongly reflects the physical properties of Ti‐incorporated zeolite catalysts and the presence of spectating molecules ("solvent") near active sites even without a bulk liquid phase. Steady‐state turnover rates of C3H6 epoxidation and product selectivities vary by orders of magnitudes, depending on the zeolite silanol ((SiOH)x) density, pore topology (MFI, *BEA, FAU), and the quantity of condensed acetonitrile (CH3CN) molecules nearby active sites, under identical reaction mechanisms sharing activated H2O2 intermediates on Ti surfaces. Individual kinetic analyses for propylene oxide (PO) ring‐opening, homogeneous diol oxidative cleavage, and homogeneous aldehyde oxidation reveal that secondary reaction kinetics following C3H6 epoxidation responds more sensitively to the changes in zeolite physical properties and pore condensation with CH3CN. Thus, higher PO selectivities achieved in hydrophilic Ti‐MFI at steady‐state reflect the preferential stabilization of transition states for C3H6 epoxidation (a primary reaction) relative to PO ring‐opening and oxidative cleavage (secondary reactions) that solvation effects that reflect interactions among condensed CH3CN within pores and the extended pore structure. [ABSTRACT FROM AUTHOR]

A novel precursor of 8YSZ nano-powders was precipitated from aqueous solutions using an antisolvent crystallization technique. Water was used as a solvent and ethanol was used as an antisolvent. During this experiment, the effect of initial concentration and mixing pattern on solid-state properties, such as microstructure particle size, agglomeration, and particle size distribution, of precursors and 8YSZ nano-powders were investigated. A series of analyses of as-obtained precursors and 8YSZ nano-powders showed that the lower initial concentration and injection mixing patterns, which provided a high supersaturation level and a stronger effect of ethanol as a dispersant, resulted in well-dispersed and small-sized powders. Further investigating the sintering and electrical properties of sintered 8YSZ ceramics, it was found that these properties were a strong function of particle sizes changed by various initial concentrations and mixing patterns. The density and conductivity of the sintered ceramics first increased and then decreased with the increasing particle size of 8YSZ nano-powders, which may be because of the as-obtained appropriate particle size (55–60 nm) from the optimal operating parameter (injection mixing patterns with high initial concentration) in favor of preventing grain coarsening in the sintering process. This work showed the potential to prepare the desired solid-state properties of 8YSZ nano-powders by changing operating parameters via an antisolvent crystallization technique. [ABSTRACT FROM AUTHOR]

Hydrogenolysis of lignin to monomers has been extensively explored, but a systematic investigation of Ru-based catalysts for lignin hydrogenolysis was rare. Herein, we studied the effects of acid, Ru particle size, and solvent on lignin depolymerization. Ru-based catalysts with high acid concentrations gave a high monomer yield from lignin depolymerization. Ru loaded on the SiO2 with the plane structure was more active than those Ru/zeolite catalysts with microporous. Smaller Ru nanoparticles greatly facilitated the lignin depolymerization, which can be prepared using NaBH4 as the reductant. The addition of 20% of water into ethanol remarkably enhanced the monomer yield and altered the monomer distributions, in which the high-temperature water released the protons that promoted the hydrolysis of lignin apart from the hydrogenolysis over Ru. [ABSTRACT FROM AUTHOR]