A Combined Experimental/Computational Study of Dicationic Ionic Liquids with Bromide and Tungstate Anions.

A panel of dicationic ionic liquids (DILs) with different rigid xylyl (ortho, meta, para) spacers and different anions (bromide and tungstate) has been synthetised and characterised through different experimental and computational techniques. Differences and analogies between the systems are analysed using information derived from their DFT structures, semiempirical dynamics, thermal behaviour, and catalytic properties versus the well-known reaction of CO added to epichlorohydrin. A comparison between the proposed systems and some analogues that present non-rigid spacers shows the key effect displayed by structure rigidity on their characteristics.

Betaine mediated enhancement of thermal stability and acidity tolerance of vanadium(V) solutions.

A panel of novel vanadium(IV)-betaine complexes has been synthesized according to new and efficient methodologies and characterized through both spectroscopic techniques and thermal analyses. Vanadium(IV)-betaine solutions have been electrochemically oxidized and the effect of betaine ligands on the thermal and pH stability of vanadium(V) solutions has been evaluated under different temperature and acidity conditions. The obtained results displayed a remarkable effect for both of the examined parameters, achieving the preparation of aqueous vanadium(V) solutions displaying long term stability at more than 55 °C under mild acidic conditions.

The Structure-Property Relationship of Pyrrolidinium and Piperidinium-Based Bromide Organic Materials.

Two couples of dicationic ionic liquids, featuring pyrrolidinium and piperidinium cations and different linker chains, were prepared and characterized. 1,1'-(propane-1,3-diyl)bis(1-methylpyrrolidinium) bromide, 1,1'-(octane-1,8-diyl)bis(1-methylpyrrolidinium) bromide, 1,1'-(propane-1,3-diyl)bis(1-methylpiperidinium) bromide, and 1,1'-(octane-1,8-diyl)bis(1-methylpiperidinium) bromide were synthesized in quantitative yields and high purity and thermally characterized through TGA and DSC analysis. In this study, we propose a preliminary comparative evaluation of the effect of the linker chain length and of the size of the aliphatic ammonium ring on the thermal and solubility properties of bromide dicationic ionic liquids.

A Specific Interaction between Ionic Liquids' Cations and Reichardt's Dye.

Solvatochromic probes are often used to understand solvation environments at the molecular scale. In the case of ionic liquids constituted by an anion and a cation, which are designed and paired in order to obtain a low melting point and other desirable physicochemical properties, these two indivisible components can interact in a very different way with the probe. This is the case with one of the most common probes: Reichardt's Dye.

Expanding the Chemical Space of Benzimidazole Dicationic Ionic Liquids.

Benzimidazole dicationic ionic liquids (BDILs) have not yet been widely explored in spite of their potential. Therefore, two structurally related families of BDILs, paired with either bromide or bistriflimide anions and bearing alkyl spacers ranging from C3 to C6, have been prepared. Their thermal properties have been studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), while their electrical properties have been assessed by cyclic voltammetry (CV).

An insight into the intermolecular vibrational modes of dicationic ionic liquids through far-infrared spectroscopy and DFT calculations.

Dicationic ionic liquids (DILs) are a subclass of the ionic liquid (IL) family and are characterized by two cationic head groups linked by means of a spacer. While DILs are increasingly attracting interest due to their peculiar physico-chemical properties, there is still a lack of understanding of their intermolecular interactions. Herein, we report our investigations on the intermolecular vibrational modes of two bromide DILs and of a bistriflimide DIL.

Systematic Synthesis and Properties Evaluation of Dicationic Ionic Liquids, and a Glance Into a Potential New Field.

Dicationic ionic liquids (DILs), a subset of the ionic liquid (IL) family, have attracted growing interest in recent years, and the range of applications within which they are investigated is constantly expanding. However, data which allows structure to property correlation of a DIL is still limited, and thus selecting an appropriate salt to address a specific challenge can be problematic. In comparison to traditional ILs, DILs physico-chemical properties can be tuned by changing the length and type of spacer which connects the cationic heads as well as the type of cation.