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Comb-shaped ionic liquid polymers P[VB(EG)Im][OH] ( = 0, 2, 3, 4) with varying polymerization degrees of polyether groups were successfully synthesized and characterized by FTIR, NMR, and ESI-MS. The Knoevenagel condensation reaction was selected as a model reaction to evaluate their catalytic performances. The influence of the polymerization degree of polyether groups on catalytic activity was studied. The results indicated that higher catalytic activity was obtained with increasing polymerization degree, owing to the enhancement of surface activity and the high local center activity concentration of the ionic liquid polymers. Among these ionic liquid polymers, P[VB(EG)Im][OH] exhibited the best catalytic performance owing to the OH anion, higher surface activity, and easy formation of hydrogen bonds with active centers. Using P[VB(EG)Im][OH] as the catalyst, the influence of solvent types on the catalysis effect was investigated. When dimethyl sulfoxide was used as the solvent, 97.6% yield was achieved because of its higher polarity and higher compatibility with reactants.
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http://dx.doi.org/10.1021/acs.langmuir.5c02322 | DOI Listing |
ChemSusChem
September 2025
Institute of Technical and Macromolecular Chemistry, University of Hamburg, Bundesstraße 45, 20146, Hamburg, Germany.
This article presents an advanced iteration of the polyoxometalate (POM)-Ionosolv concept to generate biobased methyl formate in high yield and a bleached cellulose pulp from lignocellulosic biomass in a single-step operation by using redox-balanced POM catalysts and molecular oxygen in alcoholic ionic liquid (IL) mixtures. The performance of the three Ionosolv-ILs triethylammonium hydrogen sulfate ([TEA][HSO]), N,N-dimethylbutylammonium hydrogen sulfate ([DMBA][HSO4]), and tributylmethylphosphonium methyl sulfate ([TBMP][MeSO]), mixed with methanol (MeOH) (30/70 wt%), is evaluated by methyl formate yield from extracted hemicellulose and lignin as well as purity of the bleached cellulose pulp in the presence of various Keggin-type POMs. The redox-balanced HPVMnMoO POM catalyst in [TBMP][MeSO]/MeOH emerge as the most effective combination, achieving 20% methyl formate yield from commercial beech wood.
View Article and Find Full Text PDFJ Mass Spectrom
October 2025
Department of Chemistry and Technology of Drugs, "Sapienza" University of Rome, Rome, Italy.
Ionic liquids (ILs) are a class of organic salts with melting points below 100°C. Owing to their unique chemical and physical properties, they are used as solvents and catalysts in various chemical transformations, progressively replacing common volatile organic solvents (VOCs) in green synthetic applications. However, their intrinsic ionic nature can restrict the use of mass spectrometric techniques to monitor the time progress of a reaction occurring in an IL medium, thus preventing one from following the formation of the reaction products or intercepting the reaction intermediates.
View Article and Find Full Text PDFACS Electrochem
September 2025
School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
The study of electrochemical oxidations has wide-ranging implications, from the development of new electrocatalysts for fuel cells for energy conversion, to the synthesis of fine chemicals. 2,2,6,6-Tetramethylpiperidine-1-oxyl (TEMPO) has been used for decades as a sustainable, metal-free mediator for chemical oxidations and is now being used for electrochemical oxidations. We describe here a novel approach to TEMPO-mediated electrooxidations, in which the chemical input and waste generated during electrooxidations of alcohols are minimized by using a multifunctional room temperature ionic liquid (RTIL) to facilitate flow electrosynthesis.
View Article and Find Full Text PDFNanoscale Adv
July 2025
University of Kentucky, Department of Chemical and Materials Engineering 177 F.P. Anderson Tower Lexington Kentucky 40506-0046 USA
The crystallization behavior of ionic liquids (ILs) 1-butyl-3-methylimidazolium [BMIM] hexafluorophosphate [PF] and chloride [Cl] is investigated upon confinement in 2.3 or 8.2 nm diameter silica nanopore arrays, along with the effects of covalently modifying the pore walls with 1-(3-trimethoxysilylpropyl)3-methylimidazolium [TMS-MIM] groups.
View Article and Find Full Text PDFChem Commun (Camb)
September 2025
School of Chemistry and Life Resources, Renmin University of China, Beijing, 100872, China.
Through molecular dynamics simulations of imidazolium-based ionic liquid-water mixtures, it was found that the trace water leads to an anomalous non-monotonic change in the diffusion coefficients of ionic liquid, characterized by an initial decrease followed by an increase. Hydrogen bond analysis revealed that this unusual trend is governed by the weighted hydrogen bond lifetime, reflecting the stability of the hydrogen-bond network, rather than simply the number or energy of hydrogen bonds.
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