Synthesis and Properties of Magnetic Aryl-Imidazolium Ionic Liquids with Dual Brønsted/Lewis Acidity

An overview of magnetic ionic liquids: From synthetic strategies to applications in microextraction techniques

Remarkable progress has been achieved in the application of magnetic ionic liquids in microextraction-based procedures. These materials exhibit unique physicochemical properties of ionic liquids featuring additional responses to magnetic fields by incorporating a paramagnetic component within the chemical structure. This intriguing property can open new horizons in analytical extractions because the solvent manipulation is facilitated. Moreover, the tunable chemical structures of magnetic ionic liquids also allow for task-specific extractions that can significantly increase the method selectivity. This review aimed at providing an up-to-date overview of articles involving synthesis, physicochemical properties, and applications of magnetic ionic liquids highlighting recent developments and configurations. Moreover, a section containing critical evaluation and future trends in magnetic ionic liquid-based extractions is included.

Synthesis, structural analysis, electrochemical and magnetic properties of tetrachloroferrate ionic liquids

Eight ionic liquids have been synthesized with the tetrachloroferrate anion and varying cations, with the general formula of [RA]⁺[FeCl₄]⁻ (R = –CH₃, –CH₂C₆H₅; A = pyridine, benzimidazole, trimethylamine, triphenylphosphine).

Tunable Aryl Imidazolium Recyclable Ionic Liquid with Dual Brønsted-Lewis Acid as Green Catalyst for Friedel-Crafts Acylation and Thioesterification

Unique tunable aryl imidazolium ionic liquids successfully catalyzed Friedel-Crafts acylation and thioesterification in sealed tubes. These reactions can form a C-C bond and a C-S bond with high atom economy. Ionic liquids exhibited high activity and catalyzed essential reactions with good to excellent yields while retaining their catalytic activities for recycling.

Novel Aryl-Imidazolium Ionic Liquids with Dual Brønsted/Lewis Acidity as Both Solvents and Catalysts for Friedel–Crafts Alkylation

Unique tunable aryl-imidazolium magnetic ionic liquids with dual functions as a solvent–catalyst and dual Brønsted–Lewis acidity (B-L MILs) are applied for Friedel–Crafts alkylation without additional solvents. The catalytic properties of these B-L MILs in the Friedel–Crafts alkylation of p-xylene with benzyl chloride are investigated. The various reaction parameters, including the catalyst dosage, reaction time, reaction temperature, molar ratio of reactants, and reusability, are discussed. The results show that the B-L MIL 5c has more excellent product selectivity (>99%) and reactant conversion (>99%) under the following optimum conditions (reaction temperature = 80 °C, reaction time = 0.5 h, molar ratio of p-xylene to benzyl chloride = 6:1, and catalyst 5c dosage = 1.0 mole %) than traditional catalysts reported in the previous literature. Specifically, due to the mesomeric effect between the FeCl4 anion and hydrogen atom at cationic moiety, the catalyst B-L MILs with the molar fraction of FeCl3 equal to 0.5 can be easily recovered and provide satisfactory catalytic activity after being re-used six times.

Synthesis of novel magnetic ionic liquids as high efficiency catalysts for extraction-catalytic oxidative desulfurization in fuel oil

Deep desulfurization of magnetic ionic liquids [C₄(mim)₂]Cl₂/2FeCl₃.