Unexpected solvation-stabilisation of ions in a protic ionic liquid: insights disclosed by a bond energetic study

Abstract

Accurate acidity studies of different families of substrates in a pure protic ionic liquid (PIL) show that solute ions in the PIL are free from specific ion associations and the solvation behaviour of PILs is closely related to the number of dissociable protons.

Efficient transformation of CO2 to cyclic carbonates using bifunctional protic ionic liquids under mild conditions

“…The experiments and spectrum results indicated that the DBPILs 1f could addition to 2f and further generate 1h with a hydroxyl group, because of the "super-dissociating" feature of the protic ionic liquids. 72 Furthermore, 1h could not activate CO2 and had a relatively weak H-bond interaction with epoxide compare to the powerful H-bonding of 1f, which led to the reduction of the yields in the recycle experiments. energy of ring-opening step.…”

CO2 Absorption by DBU-Based Protic Ionic Liquids: Basicity of Anion Dictates the Absorption Capacity and Mechanism

“…The regression analyses show that the acidities of structural and electronic different organic substrates, i.e., RO-H, N-H, N + -H, and RCOO-H, linearly correlate with those in water. However, instead of forming a unified straight line, which is the case found for the analogous acidity correlation between a PIL EAN (ethylammonium nitrate) and water (Kanzaki et al, 2016), each individual series exhibits different slope and intercept (Figure 2) (Wang et al, 2018a). These linear acidity correlations between PILs and molecular solvent water are highly useful for accessing p K a values of compounds in neat PILs that are difficult to determine due to the solvent leveling effect.…”

“…In our previous work, we have successfully measured the acidities for several series of commonly seen organic acids in a DBU-based PIL, i.e., [DBUH][OTf] (OTf − = triflate) (Wang et al, 2018a). The regression analyses show that the acidities of structural and electronic different organic substrates, i.e., RO-H, N-H, N + -H, and RCOO-H, linearly correlate with those in water.…”

“…Superbase DBU-derived PILs [DBU = 1,5-diazabicyclo[5.4.0]-5-undecene] are promising solvent systems for the CO 2 absorption, previous studies have shown that CO 2 has a considerable solubility in these PILs (Losetty et al, 2017; Zhu et al, 2017). In this work, in order to systematically investigate the relationship between the absorption capacity and thermodynamic properties of ILs, firstly we synthesized 11 DBU-based PILs, i.e., [DBUH][X], whose anions (X − ) are of different basicities (Figure 1), then the acidities of conjugated acids (HX) of these anions were determined or extrapolated from the known correlations obtained from previous study (Wang et al, 2018a). Next the apparent kinetics as well as capacity for CO 2 absorption in [DBUH][X] were measured, whereby the relationship between the basicity of anion X − and CO 2 capture abilities of [DBUH][X] was established.…”

Structural features of selected protic ionic liquids based on a super-strong base

“…and [DBUH][TfO] have been studied in the past by different groups 2,5,6,16,40. [DBUH][IM14] has been prepared for the first time in this report and no previous information exists on this PIL.…”