Physical and Electrochemical Analysis of -Alkylpyrrolidinium-Substituted Boronium Ionic Liquids.

In this work, a series of novel boronium-bis(trifluoromethylsulfonyl)imide [TFSI] ionic liquids (IL) are introduced and investigated. The boronium cations were designed with specific structural motifs that delivered improved electrochemical and physical properties, as evaluated through cyclic voltammetry, broadband dielectric spectroscopy, densitometry, thermogravimetric analysis, and differential scanning calorimetry. Boronium cations, which were appended with -alkylpyrrolidinium substituents, exhibited superior physicochemical properties, including high conductivity, low viscosity, and electrochemical windows surpassing 6 V.

Correction: Ionic liquids of superior thermal stability. Validation of PPh as an organic cation of impressive thermodynamic durability.

[This corrects the article DOI: 10.1039/D0RA03220D.].

Cyclopropane as an Unsaturation "Effect Isostere": Lowering the Melting Points in Lipid-like Ionic Liquids.

The replacement of unsaturation with a cyclopropane motif as a (bio)isostere is a widespread strategy in bacteria to tune the fluidity of lipid bilayers and protect membranes when exposed to adverse environmental conditions, e.g., high temperature, low pH, etc.

Ionic liquids of superior thermal stability. Validation of PPh as an organic cation of impressive thermodynamic durability.

Recent work by Wasserscheid, suggests that PPh is an organic molecular ion of truly exceptional thermal stability. Herein we provide data that cements that conclusion: specifically, we show that aliphatic moieties of modified PPh -based cations incorporating methyl, methylene, or methine C-H bonds burn away at high temperatures in the presence of oxygen, forming CO, CO, and water, leaving behind the parent ion PPh . The latter then undergoes no further reaction, at least below 425 °C.

Lipidic ionic liquid stationary phases for the separation of aliphatic hydrocarbons by comprehensive two-dimensional gas chromatography.

Lipidic ionic liquids (ILs) possessing long alkyl chains as well as low melting points have the potential to provide unique selectivity as well as wide operating ranges when used as stationary phases in gas chromatography. In this study, a total of eleven lipidic ILs containing various structural features (i.e.

Solubility of CO and NO in an Imidazolium-Based Lipidic Ionic Liquid.

Imidazolium-based ionic liquids have been extensively studied for their ability to dissolve a wide variety of gases and for their potential to be used as separation agents in industrial processes. For many short chain 1-alkyl-3-methylimidazolium bistriflimde salts, CO and NO solublities are very similar. In this work, the solubility of CO and NO has been measured in the lipidic ionic liquid 1-methyl-3-(Z-octadec-9-enyl)imidazolium bistriflimide ([oleyl-mim][NTf]) at 298 K, 310 and 323 K up to ∼2 MPa.

Crystal structure of a methimazole-based ionic liquid.

The structure of 1-methyl-2-(prop-2-en-1-ylsulfan-yl)-1H-imidazol-3-ium bromide, C7H11N2S(+)·Br(-), has monoclinic (P21/c) symmetry. In the crystal, the components are linked by N-H⋯Br and C-H⋯Br hydrogen bonds. The crystal structure of the title compound undeniably proves that methimazole reacts through the thione tautomer, rather than the thiol tautomer in this system.

Fusion and Thermal Degradation Behavior of Symmetric Sulfur-Containing Quaternary Ammonium Bromides.

Quaternary ammonium salts are widely used in consumer products and industrial processes, where their instability at elevated temperatures limits their range of applications. In this work, the thermal behavior of a new class of quaternary ammonium salts was investigated using differential scanning calorimetry. These salts contain a sulfur atom in each chain at the fourth position from the central nitrogen and are thus termed thiaquats.

Liquid-liquid equilibria of binary mixtures of a lipidic ionic liquid with hydrocarbons.

Although structurally diverse, many ionic liquids (ILs) are polar in nature due to the strong coulombic forces inherent in ionic compounds. However, the overall polarity of the IL can be tuned by incorporating significant nonpolar content into one or more of the constituent ions. In this work, the binary liquid-liquid equilibria of one such IL, 1-methyl-3-(Z-octadec-9-enyl)imidazolium bistriflimide, with several hydrocarbons (n-hexane, n-octane, n-decane, cyclohexane, methylcyclohexane, 1-octene) is measured over the temperature range 0-70 °C at ambient pressure using a combination of cloud point and gravimetric techniques.

The effect of the sulfur position on the melting points of lipidic 1-methyl-3-thiaalkylimidazolium ionic liquids.

A series of novel lipid-inspired ionic liquids have been synthesized employing the thiol-ene "click" reaction in a single-step process. The thermal properties were determined by differential scanning calorimetry (DSC) and showed observable trends between the C16, C18, and C20 analogues. The minimum melting points for each equivalent chain length series occur at sequential odd sulfur positions, 3, 5, and 7 for the C16, C18, and C20 series, respectively.

On the formation of a protic ionic liquid in nature.

The practical utility of ionic liquids (ILs) makes the absence (heretofore) of reported examples from nature quite puzzling, given the facility with which nature produces many other types of exotic but utilitarian substances. In that vein, we report here the identification and characterization of a naturally occurring protic IL. It can be formed during confrontations between the ants S.

Synthesis of new lipid-inspired ionic liquids by thiol-ene chemistry: profound solvent effect on reaction pathway.

The synthesis of a series of new lipid-inspired ionic liquids through thiol-ene "click" reaction with a single-step process. This synthesis offers considerable promise as an efficient and orthogonal method to construct structurally diverse imidazolium-type ionic liquids with linear and branched cationic tails, as well as versatility in the placement of the sulfur heteroatom. Profound solvent effect in this ene reaction regioselectivity has been observed.

Ionic liquids of superior thermal stability.

In a head-to-head study, ILs based upon tetraarylphosphonium cations exhibit superior long-term thermal stability compared to familiar salts based upon imidazolium, quaternary ammonium, or tetraalkylphosphonium cations.

Structure-based tuning of T(m) in lipid-like ionic liquids. Insights from Tf2N- salts of gene transfection agents.

Ionic liquids of cations bearing two lipid-like aliphatic tails are shown to have values of T(m) that can be very low, and that can be tuned up or down by the addition, deletion, or combination of dipolar modules and side-chain double bonds.

A new building block for electroactive organic materials? Synthesis, cyclic voltammetry, single crystal X-ray structure, and DFT treatment of a unique boron-based viologen.

A boronium-based paraquat analog undergoes reductions at more negative potentials than paraquat itself, making it a promising building block for electroactive materials.

Constitutional dynamic systems of ionic and molecular liquids.

The ionic liquids N-methylpyridinium-2-carboxaldehyde Tf(2)N(-) and N-methylpyridinium-3-carboxaldehyde Tf(2)N(-) form readily-reversible covalent bonds with protic nucleophiles, creating all-liquid constitutionally dynamic materials.