Polycations. Part X. LIPs, a new category of room temperature ionic liquid based on polyammonium salts

Extended Electrochemical Windows Made Accessible by Room Temperature Ionic Liquid/Organic Solvent Electrolyte Systems

“…[17,18,[21][22][23] The choice of cation and anion pair in the synthesis of ionic liquids is vast and several improvements have been made over the years with regard to the available building blocks for these relatively novel solvents. The anions, in particular, have been substituted by increasingly stable alternates; for example, hexafluorophosphate ([PF 6 ] À ) and tetrafluoroborate ([BF 4 ] À ) anions, which are known to be susceptible to hydrolysis, and thus potentially bring about the evolution of toxic hydrogen fluoride; [24][25][26][27][28] have been replaced by more hydrophobic anions such as bis(trifluoromethylsulfonyl)imide ([NTf 2 ] À ) [6] and trifluorotris(pentafluoroethyl)phosphate…”

Exploring the Use of Ionic Liquid Mixtures to Enhance the Performance of Dicationic Ionic Liquids

“…This asymmetric dication with quaternary ammonium groups on both ends has a smaller effective r H in comparison to the other dications, even including (CH 3 ) 3 NC 5 Mim 2+ and MimC 6 Mim 2+ . Indeed, the self-diffusion coefficients of the (CH 3 ) 3 NC 5 Mpyrr 2+ dication are not much slower than those for P 1 all three components are strongly coupled, in contrast to the triphenylphosphonium mixtures. This is possibly due to the structural similarity of both ends of the (CH 3 ) 3 Figure 9 shows that self-diffusion of the NTf 2 − anion in the triphenylphosphonium mixtures is less strongly coupled to the bulk viscosity than in the other cases, as was found for the P 1 EOE + cation.…”

“…Some time ago, Lall, Engel and collaborators reported the synthesis and properties of several series of functionalized geminal ammoniumbased phosphate DILs among other polycationic salts. [1][2][3][4] Ohno and co-workers also reported on imidazolium based DILs 5 and DILs containing polyether bridges. 6 The synthesis and properties (including thermal stability and viscosity) of symmetrical and asymmetrical DILs based on imidazolium, pyrrolidinium and ammonium ions have also been reported by Armstrong and co-workers.…”

Glycoside-Based Ionic Liquids

“…Other commonly used anions for ionic liquids, such as tetrafluoroborate and hexafluorophosphate, also undergo hydrolysis at sufficiently rapid rates that would cause difficulties for their use with either aqueous solvents or hydroxylic cations. While the hexafluorophosphate anion undergoes hydrolysis most rapidly only under acidic conditions (Freire et al 2010), the preparation of the ionic liquids using hexafluorophosphoric acid can lead to significant formation of the (hydrolyzed) phosphate salt (Lall et al 2000). Similarly, the alternative approach for the preparation of the phosphate salts (liquid ionic phosphates, LIPs) involving the use of 98% phosphoric acid (Lall et al 2002) similarly experiences difficulty when cations are used that bear hydroxylic sites.…”