Reaction Solvent Research Articles

Enhanced synthesis of antibody-functionalized gold nanoparticles for multiplexed exosome detection via mass signal amplification in LDI-TOF MS.

We present a novel method for sensitive exosomal protein detection using organic matrix-free laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) and gold nanoparticles (AuNPs) functionalized with mass tags for signal amplification (Am-tags). Target exosomes were captured by specific antibodies on AuNPs and a biochip, where the antibody-presenting AuNPs (Ab/Am-tag@AuNPs) contained excess Am-tags. LDI-TOF MS analysis revealed the mass signal of Am-tags on Ab/Am-tag@AuNPs, indicating the presence of target exosomes. Thus, the target signal was amplified by a large number of Am-tags, resulting in enhanced sensitivity. We optimized the protocol to prepare stable Ab/Am-tag@AuNPs, focusing on parameters such as the concentration and ratio of thiol molecules for AuNP functionalization, suitable solvents for the coupling reaction, and amount of antibodies conjugated to the AuNPs. Subsequently, we evaluated the ability of our method to detect exosomes isolated from three cell lines, NIH3T3, MCF7, and HeLa, using an anti-Rab5 immobilized gold chip and anti-CD63/Am-tag@AuNPs with LDI-TOF MS analysis. Calibration curves constructed for the three cell lines showed a linear relationship with an excellent limit of detection. Finally, we emphasized the versatility of our method for the quantitative detection of exosomal proteins CD63 and mucin 1 (MUC1) using two types of Am-tags. LDI-TOF MS analysis revealed the presence of CD63 and MUC1 at different expression levels in HeLa and MCF7 cancer cells. Our findings clearly indicate the potential of Ab/Am-tag@AuNPs as a sensitive and reliable approach for identifying biomarkers in exosomes, providing valuable insights into their utility in biomedical research and clinical settings.

Highly efficient hydrolysis of cellulose to sugars using supercritical CO2 as a green acid catalyst and solvent

Rapid depolymerization of cellulose into processable monomers (e.g., sugars) using solid acid catalysts is an important step for cost-effective biofuel and biochemical production, but has not yet been achieved due to the limited contact between solid cellulose and solid catalysts. Herein, the unique roles of supercritical CO2 (i.e., scCO2) as an in-situ acid catalyst and reaction solvent in achieving the ultra-fast full solid catalytic hydrolysis of cellulose are disclosed for the first time. When the ball-milling pretreated cellulose was hydrolyzed using oxidized carbon catalysts at 150 °C and 100–300 bar-CO2, the hydrolysis kinetics remarkably increased by 3× for conversion and 5× for glucose, resulting in ∼90% conversion and ∼85% total sugar selectivity at 20 min. The hydrolysis rate obtained with scCO2 here was higher than conventional ones with toxic and unrecyclable homogeneous catalysts (e.g., HCl) under harsh reaction conditions (i.e., 180–220 °C and pH of 1–2). A comprehensive reaction engineering study (e.g., temperature, CO2 pressure, stirring speed, catalyst acid properties) combined with the estimation of the solution pH by the CO2 phase equilibrium model and the in-situ and ex-situ monitoring of the phase behavior of the H2O/scCO2 solution were conducted to quantify the activity promotion by scCO2 and understand the acid-solvent roles of scCO2 toward the enhanced hydrolysis of cellulose. Specifically, the formation of the Pickering emulsions at the interface between scCO2 and water and their impact on the enhancement of the cellulose-carbon contact were proposed and verified in detail.

Hydrophobic Surfactant-DNA Complex (Surf-DNA) Enables DNA-Encoded-Library-Compatible Decarboxylative Arylation under Anhydrous Conditions.

DNA-encoded libraries (DELs) are a key technology for identifying small-molecule hits in both the pharmaceutical industry and academia, but their chemical diversity is largely limited to water-compatible reactions to aid in the solubility and integrity of encoding DNA tags. To broaden the DEL chemical space, we present a workflow utilizing DNA-cationic surfactant complexation that enables dissolution and reactions on-DNA in anhydrous organic solvents. We demonstrate its utility by developing DEL-compatible photoredox decarboxylative C(sp2)-C(sp3) coupling under water-free conditions. The workflow is optimized for the 96-well format necessary for large-scale DEL productions, and it enables screening and optimization of DEL-compatible reactions in organic solvents.

Unveiling the integrated function of metallo‐/ionic‐covalent organic polymers for boosting atmospheric CO2 conversion

Unveiling the integrated function of metallo‐/ionic‐covalent organic polymers for boosting atmospheric <scp>CO₂</scp> conversion

Boosting transformation of glucose and fructose to 5-hydroxymethylfurfural by a strategy of dual catalyst in biphasic solvent system with salt

5-Hydroxymethylfurfural (HMF) derived from biomass can be converted to a variety of high-value chemicals. Transformation of glucose and fructose to HMF is the typical reactions involved in transformation of raw biomass to HMF. However, poor stability of heterogeneous solid acid and the side reactions of HMF consumption still is a challenge for the entitled reaction. In the present work, a strategy of catalyst with dual acid of Lewis acid and Brønsted acid combined with the biphasic solvent system of organic-aqueous salt is employed to design the effective catalytic system for the transformation of glucose and fructose to HMF. An SiO2-Zr-P heterogeneous solid acid with the dual acid sites was prepared by grafting of zirconium dioxide on silica followed by its phosphation. The surface grafted zirconium dioxide was transformed to the zirconium phosphate with the formula of Zr(HPO4)2·H2O. Both the Lewis acid and Brønsted acid of the SiO2-Zr-P are enhanced and their influences for the entitled reaction was investigated. The prepared catalyst was employed to catalyse the entitled reaction in the biphasic solvent of tetrahydrofuran-aqueous NaCl solvent, giving 99.9% yield of HMF for fructose and 75.2% yield of HMF for glucose. The catalyst showed good stability and can be applied for the catalytic transformation of various sugars to corresponding HMF and fufural with satisfied yield.

Increasing the Particle Size and Magnetic Property of Iron Oxide Nanoparticles through a Segregated Nucleation and Growth Process.

Iron oxide nanoparticles (IONs) with good water dispersibility were prepared by the thermal decomposition of iron acetylacetonate (Fe(acac)3) in the high-boiling organic solvent polyethylene glycol (PEG) using polyethyleneimine (PEI) as a modifier. The nucleation and growth processes of the crystals were separated during the reaction process by batch additions of the reaction material, which could inhibit the nucleation but maintain the crystal growth, and products with larger particle sizes and high saturation magnetization were obtained. The method of batch addition of the reactant prepared IONs with the largest particle size and the highest saturation magnetization compared with IONs reported using PEG as the reaction solvent. The IONs prepared by this method also retained good water dispersibility. Therefore, these IONs are potentially suitable for the magnetic separation of cells, proteins, or nucleic acids when large magnetic responses are needed.

Asymmetric Aldol Reactions Catalyzed by Polymeric Self-Assembly with Side-Chain Dipeptide Pendants.

To explore the role of proline amide moieties in polymer-supported organocatalysts, side-chain l-proline-l-alanine (Pro-Ala) dipeptide-containing block copolymers were synthesized, and their catalytic potential for the aldol reaction was explored. The dipeptide monomer (Boc-Pro-Ala-HEMA) was polymerized to prepare block copolymers in the presence of hydrophilic poly(poly(ethylene glycol) methyl ether methacrylate) (PPEGMA) and hydrophobic poly(methyl methacrylate) (PMMA) macro-chain transfer agents. Boc group expulsion from the block copolymers produced double hydrophilic PPEGMA-b-P(Pro-Ala-HEMA) (1b) and amphiphilic PMMA-b-P(Pro-Ala-HEMA) (1c) polymers. The solution behaviors of the polymers were studied by various physical techniques, which showed the formation of self-assembled aggregates of 1c in water and N,N-dimethylformamide (DMF)/water solvent mixtures. These polymers are used as organocatalysts during the aldol reaction of cyclohexanone and 4-nitrobenzaldehyde in different solvent polarities, catalyst loadings, temperatures, and reaction times. This work emphasizes superior catalytic activity of 1c at lower catalyst loadings (5%) while maintaining high conversion (95%) and enantioselectivity (94%) across multiple recycling cycles in DMF/water at a 3:1 ratio (v/v).

Nitrile Vibrational Lifetimes as Probes of Local Electric Fields.

Optical measurements of electric fields have wide-ranging applications in the fields of chemistry and biology. Previously, such measurements focused on shifts in intensity or frequency. Here, we show that nitrile vibrational lifetimes can report local electric fields through ultrasensitive picosecond mid-infrared-near-infrared double-resonance fluorescence spectro-microscopy on Rhodamine 800. Using a robust convolution fitting approach, we observe that the nitrile vibrational lifetimes are strongly linearly correlated (R2 = 0.841) with solvent reaction fields. Supported by density functional theory, we rationalize this trend through a doorway model of intramolecular vibrational energy redistribution. This work provides new fundamental insights into the nature of vibrational energy flow in large polyatomic molecular systems and establishes a theoretical basis for electric field sensing with vibrational lifetimes, offering a new experimental dimension for probing intracellular electrostatics.

Silsesquioxane Cages under Solvent Regimen: The Influence of the Solvent on the Hydrolysis and Condensation of Alkoxysilane.

This study investigates the formation mechanisms of oligomeric phenyl silanols, focusing on polyhedral oligomeric silsesquioxane (POSS) and double-decker silsesquioxane (DDSQ) derivatives. Combining literature reports and crystal structures of solvated derivatives obtained in our laboratory, we show that the solvent choice significantly influences their structures. POSS-based silanols prefer aprotic solvents like THF, preserving dimerization, while double-deckers form stable architectures in protic solvents like isopropanol. This discrepancy arises from different stabilization mechanisms. Our findings enhance our understanding of hydrolytic condensation involving trimethoxyphenylsilane and suggest aprotic solvents for efficient reactions with POSS-based silanols.

Synthesis of InZrOx nanosheets and its application in CO2 hydrogenation to methanol

Synthesis of methanol via CO2 hydrogenation is a very important reaction. In recent years, the In2O3 based catalysts were proved to be a sort of promising catalysts to accelerate this reaction, which have aroused extensive attention. However, design of novel In2O3 based catalysts that can efficiently produce methanol from CO2 hydrogenation at low temperature is still in great need. Herein we fabricated the InZrOx nanosheets via a simple solvothermal method, which had peculiar surface structure and plenty of oxygen defects. The InZrOx nanosheets displayed excellent low temperature catalytic performance in a slurry reactor. The methanol selectivity (90 %) and activity (1.4 mmol gIn-1h−1) were achieved at 180 °C, which are 2.3 and 1.6 times than that of the counterpart nanoparticles, respectively. Water as a clean and cheap reaction solvent played a crucial role, which participated in the kinetic process of the catalysis. The particular catalyst structure and the solvent effect of water accounting for the outstanding reaction results.

Efficient Reductive N-11C-Methylation Using Arylamines or Alkylamines and InSitu-Generated [11C]Formaldehyde From [11C]Methyl Iodide.

Reductive N-11C-methylation using [11C]formaldehyde and amines has been used to prepare N-11C-methylated compounds. However, the yields of the N-11C-methylated compounds are often insufficient. In this study, we developed an efficient method for base-free reductive N-11C-methylation that is applicable to a wide variety of substrates, including arylamines bearing electron-withdrawing and electron-donating substituents. A 2-picoline borane complex, which is a stable and mild reductant, was used. Dimethyl sulfoxide was used as the primary reaction solvent, and glacial acetic acid or aqueous acetic acid was used as a cosolvent. While reductive N-11C-methylation efficiently proceeded under anhydrous conditions in most cases, the addition of water to the reductive N-11C-methylation generally increased the yield of the N-11C-methylated compounds. Substrates with hydroxy, carboxyl, nitrile, nitro, ester, amide, and phenone moieties and amine salts were applicable to the reaction. This proposed method for reductive N-11C-methylation should be applicable to a wide variety of substrates, including thermo-labile and base-sensitive compounds because the reaction was performed under relatively mild conditions (70°C) without the need for a base.

White carbon dots with high quantum yield and multicolor carbon dots synthesized by the microwave method in one step

In the field of optics, carbon dots (CDs) have been extensively studied and have made rapid advancements in related fields, including bioimaging, optoelectronic devices and optical probes. However, it is difficult to efficiently synthesize high quantum yield (QY) white fluorescence CDs and multicolor CDs, which restricts their development in the field of optics. In this work, we chose formamide as the reaction solvent and used citric acid (CA) and 4-bromo-1,2-diaminobenzene to synthesize high-performance white fluorescent CDs20 with a QY of up to 87.5% and excellent stability (28 days). The reaction solvents (water, N,N-dimethylformamide and ethanol) were changed to obtain colorful CDs20 (orange, green and yellow) covering a broader visible spectrum via a microwave method. The solid model, which combines white fluorescent CDs20 and polyvinyl alcohol (PVA), exhibits strong white fluorescence as well as a solution state. To develop white-emitting diodes suitable for indoor use, a white CDs20 / PVA mixture with brilliant white fluorescence might be placed on ultraviolet (UV) chips (365 nm). The white LED had a high color purity (0.34, 0.25), excellent correlation color temperature (4250 K) and color rendering index (72.5). The results above show that white CDs have great promise for use in optical device fields.

Relationship between Solvent Polarity and Reaction Rate in Organic Synthesis

Purpose: The aim of the study was to assess the relationship between solvent polarity and reaction rate in organic synthesis. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Polar solvents tend to enhance reaction rates for polar reactions due to their ability to stabilize charged intermediates and transition states. Conversely, nonpolar solvents often accelerate nonpolar reactions by minimizing solvation effects and promoting favorable interactions between reactants. However, there are exceptions to these trends, as solvent effects can also be influenced by factors such as hydrogen bonding, solute-solvent interactions, and solvent viscosity. Additionally, the choice of solvent can impact the selectivity and yield of the desired product. Thus, understanding the interplay between solvent polarity and reaction kinetics is crucial for optimizing organic synthesis processes. Experimental studies and computational modeling techniques play key roles in elucidating these relationships and guiding solvent selection for specific reactions. Implications to Theory, Practice and Policy: Transition state theory, solvent-solute interactions and microscopic solvation models may be used to anchor future studies on assessing the relationship between solvent polarity and reaction rate in organic synthesis. Audit firms should invest in ongoing training and professional development programs to enhance the skills and knowledge of auditors. This includes staying updated on industry-specific issues, emerging risks, and advanced audit methodologies. Regulatory authorities should continue to strengthen their oversight of the audit profession. This includes periodically reviewing and updating auditing standards, enforcing compliance with auditing regulations, and imposing penalties for audit failures.

Impacts of synthesis variables on spectroscopics evaluation of biobased fatty amide as alkylammonium salt’s precursor for perovskite

Ammonium salts are widely used in chemical industries as additives in cement industries, phase change materials in thermal cooling, ionic materials in electrochromic window and multifunction medium/precursor/catalyst in solar cells to improve the efficiency and stability. This work introduces a procedural enhancement by incorporating a liquid-liquid extraction purification process, resulting in a high-purity biobased fatty amide (FA) with tri-substitution and high-purity biobased tetraalkylammonium ammonium salt (TAS). Biobased FA derived from renewable sources was synthesized via an amidation reaction between fatty acids from vegetable oil with tris(3-aminopropyl)amine under reflux conditions, producing a precursor for TAS used in perovskite solar cell (PSC). This study aimed to optimize and determine the reaction condition of biobased FA at various key synthesis variables by investigating the effects of solvent selection, reaction and crystallization, temperature, catalyst, mole ratio, and dehydrating agent on synthesis yield. A multiple liquid-liquid extraction process was employed to enhance the purity of biobased FA by tunning the selection of solvent based on its relative polarity of the reactant and products. Response surface methodology (RSM) and central composite design (CCD) were utilized to optimize the total yield and the three key variables (reaction time, crystallization time, catalyst amount) respectively. The experimental model developed in this study demonstrated a high degree of fitness with the experimental data (F-value = 27.34), p-value < 0.05) and nonsignificant lack of fit. The model predicted a maximum synthesis yield percentage of 52.62 % under optimal conditions (reaction and crystallization time of 12 and 28 hours), respectively with 4.47 % catalyst). The coefficient of determination of R2 = 0.98 shows a high correlation with the predicted values and in good agreement with the experimental values. Physicochemical properties analysis using spectroscopies techniques, confirmed improved purity with 100% abundance yield of tri-substitution biobased FA and enhanced TAS’s purity up to 60%. The optimization study sheds light on the impact of key synthesis variables on the synthesis yield and percentage abundance (purity), advancing the development of more efficient and tailored sustainable construction materials. These findings highlight the potential of using biobased FA as a sustainable source for TAS production, contributing to a more environmentally friendly approach in PSC development.

Highly defective ultra-small tetravalent MOF nanocrystals

The size and defects in crystalline inorganic materials are of importance in many applications, particularly catalysis, as it often results in enhanced/emerging properties. So far, applying the strategy of modulation chemistry has been unable to afford high-quality functional Metal–Organic Frameworks (MOFs) nanocrystals with minimized size while exhibiting maximized defects. We report here a general sustainable strategy for the design of highly defective and ultra-small tetravalent MOFs (Zr, Hf) crystals (ca. 35% missing linker, 4–6 nm). Advanced characterizations have been performed to shed light on the main factors governing the crystallization mechanism and to identify the nature of the defects. The ultra-small nanoMOFs showed exceptional performance in peptide hydrolysis reaction, including high reactivity, selectivity, diffusion, stability, and show emerging tailorable reactivity and selectivity towards peptide bond formation simply by changing the reaction solvent. Therefore, these highly defective ultra-small M(IV)-MOFs particles open new perspectives for the development of heterogeneous MOF catalysts with dual functions.

Rational construction of ZnFe2O4 decorated hollow carbon cloth towards effective electromagnetic wave absorption

As typical magnetic materials, ferrites and their composites play dominant roles in the design of high-performance electromagnetic wave (EW) absorber. Solvent thermal method is the most popular route for synthesizing ferrites, while systematical comparison research about the influence of reaction solvents of solvent thermal process on ferrite based material's EW absorption performance has rarely been carried out. Thus in this work, we adopted cotton fabric as raw material, and synthesized two kinds of zinc ferrite decorated hollow carbon cloth (CC@ZnFe2O4) composites through solvent thermal reaction where deionized water and ethylene glycol was adopted as reaction solvents, respectively. After comprehensive and detailed comparison of the structures and performances of these two ferrite composites, the CC@ZnFe2O4 synthesized in deionized water phase possesses an ideal optimal absorption efficiency for EW, that is the minimum reflection loss (RL min) of −46 dB, while the effective absorption bandwidth of CC@ZnFe2O4 composites synthesized in ethylene glycol phase is wider (4.9 GHz). The synergistic effect of impedance matching, interface polarization, magnetic resonance, and multiple reflections co-determined the ideal EW absorption performances of these two samples. The research can not only provide new guidance for the secondary utilization of waste textiles, but also become an important reference for the preparation of ferrite based high-performance EW absorbers through solvent thermal method.

Viability of Ecofriendly Ionic Liquids in Starch Plasticization and Modification

AbstractIonic liquids (IL) have emerged as the potential class of solvents for various chemical processes and reactions, including gelatinization and chemical modification of starch. Through various studies it has been established that expensive nature of ILs can be counter balanced by employing the mixture of IL/water instead of pure ILs. The IL/water system has the advantage to plasticize starch more effectively due to their synchronal effect and rational viscosity. The properties of ILs can be tempered by preferring particular cations/anions according to the specific type of starch which may be helpful in convenient dissolution and modification of starch. Starch can be modified by esterification or etherification reaction in IL medium to alter their properties and to use it in various application areas. Starch dissolution is subjected to various parameters like type of starch, nature of IL, ratio of IL/water, and temperature which has been discussed elaborately in the present review paper.

Mechanochemical Synthesis of Chromium(III) Complexes Containing Bidentate PN and Tridentate P-NH-P and P-NH-P' Ligands.

Chromium(III) complexes bearing bidentate {NH2(CH2)2PPh2: PN, (S,S)-[NH2(CHPh)2PPh2]: P'N} and tridentate [Ph2P(CH2)2N(H)(CH2)2PPh2: P-NH-P, (S,S)-(iPr)2PCH2CH2N(H)CH(Ph)CH(Ph)PPh2: P-NH-P'] ligands have been synthesized using a mechanochemical approach. The complexes {cis-[Cr(PN)Cl2]Cl (1), cis-[Cr(P'N)Cl2]Cl (2), mer-Cr(P-NH-P)Cl3 (3), and mer-Cr(P-NH-P')Cl3 (4)} were obtained in high yield (95-97%) via the grinding of the respective ligands andthe solid Cr(III) ion precursor [CrCl3(THF)3] with the aid of a pestle and mortar, followed by recrystallization in acetonitrile. The isolated complexes are high spin. A single-crystal X-ray diffraction study of 2 revealed a cationic chromium complex with two P'N ligands in a cis configuration with P' trans to P' with chloride as the counteranion. The X-ray study of 4 shows a neutral Cr(III) complex with the P-NH-P' ligand in a mer configuration. The difference in molecular structures and bulkiness of the ligands influence the electronic, magnetic, and electrochemical properties of the complexes as exhibited by the bathochromic shifts in the electronic absorption peaks of the complexes and the relative increase in the magnetic moment of 3 (4.19 μβ) and 4 (4.15 μβ) above the spin only value (3.88 μβ) for a d3 electronic configuration. Complexes 1-4 were found to be inactive in the hydrogenation of an aldimine [(E)-1-(4-fluorophenyl)-N-phenylmethanimine] under a variety of activating conditions. The addition of magnesium and trimethylsilyl chloride in THF did cause hydrogenation at room temperature, but this occurred even in the absence of the chromium complex. The hydrogen in the amine product came from the THF solvent in this novel reaction, as determined by deuterium incorporation into the product when deuterated THF was used.

Emerging Photoreforming Process to Hydrogen Production: A Future Energy

AbstractIn the quest of renewable energy technologies, solar photoreforming emerges as one of the affordable yet challenging process for converting biomass into hydrogen, hydrocarbon fuels, and chemicals. This review highlights the state‐of‐the‐art photoreforming, elucidating its underlying mechanisms for the conversion of dissipated polymers into H2 and valuable chemicals. Biomass feedstocks such as carbohydrates, agricultural residues, glycopolymers, food wastes, and waste plastics are evaluated based on their chemical composition, energy content, and sustainability aspects, exploring the selection of appropriate bio‐renewable resources, considering their abundance, availability, and potential for hydrogen production. The impact of diverse process parameters on photoreforming efficiency is explored, encompassing factors like reaction temperature, pH, catalyst loading, reactor design, solvent effect, and light intensity across various sacrificial substrates. The discussion also considers their correlation with hydrogen production rate, selectivity, and energy efficiency. This review buckles on the design and synthesis of functional photocatalysts for biomass‐derived feedstock, highlighting their photocatalytic (PC) properties in biomass reforming processes and related feedstock into valuable chemicals and biofuel. The review also delves into potential pathways for future advancements including artificial intelligence (AI) and machine learning (ML), alongside addressing the challenges and insightful perspectives within this evolving field of future green energy.

Controlling Interfacial Hydrogen Bonding at a Gold Surface: The Effect of Organic Cosolvents.

Water often serves as both a reactant and solvent in electrocatalytic reactions. Interfacial water networks can affect the transport and kinetics of these reactions, e.g., hydrogen evolution reaction and CO2 reduction reaction. Adding cosolvents that influence the hydrogen-bonding (H-bonding) environment, such as dimethyl sulfoxide (DMSO), has the potential to tune the reactivity of these important electrocatalytic reactions by regulating the interfacial local environment and water network. We investigate interfacial H-bonding networks in water-DMSO cosolvent mixtures on gold surfaces by using surface-enhanced infrared absorption spectroscopy and molecular dynamics simulations. Experiments and simulations show that the gold surface is enriched with dehydrated DMSO molecules and the mixture phase-separates to form water clusters. Simulations show a "buckled" water conformation at the surface, further constraining interfacial H-bonding. The small size of these water clusters and the energetically unfavorable H-bond conformations might inhibit H-bonding with bulk water, suppressing the proton diffusion required for efficient hydrogen evolution reaction processes.