Reaction Mechanism of Cl₂ and 1-Alkyl-3-methylimidazolium Chloride Ionic Liquids

Abstract

Systems containing 1-alkyl-3-methylimidazolium chloride ionic liquid and chlorine gas were investigated. Using relativistic density functional theory, we calculated the formation mechanism of trichloride and hydrogen dichloride anions in an Emim(+)Cl(-) + Cl(2) system. Emim(+)Cl(3)(-) forms without energy barriers. The more stable species ClEmim(+)HCl(2)(-) forms through chlorine substitution. Substitution of a H on the imidazolium ring is much easier than substitution on the alkyl side chains. Infrared, Raman, ESI-MS, and (1)H NMR spectra were measured for EmimCl, BmimCl, and DmimCl with and without Cl(2) gas. The coexistence of Cl(3)(-) and HCl(2)(-), as well as chlorine-substituted cations, was confirmed by detection of their spectroscopic signals in the Cl(2) added ionic liquids. Cl substitution appears less serious for cations with longer side chains.

Single Nanoparticle Detection in Ionic Liquids

“…Theoretical works , have explored the microscopic interactions of RTILs and nanoparticles, and extending this understanding through experimental electrochemistry is vitally important. Additionally, consideration must be given to halide impurities, which are commonly present in RTILs as residual starting materials from the synthetic process, and are known to affect the properties of the ionic liquid, such as density, electrochemical window, and viscosity, and, importantly, are also known to alter reaction outcomes. − …”

Formation of Dichlorine Monoxide for Organic Pollutant Degradation by Free Chlorine in High Chloride-Containing Water

“…We thus propose that chloride serves two important roles: one is to transform HOCl/ClO – to Cl 2 and the other is to react with Cl 2 to form polychloride monoanions, Cl n – ( n ≥ 3) (eq ). − normalH normalO normalC normall + normalH + + normalC normall − ⇋ normalC normall 2 + normalH 2 normalO goodbreak0em2em⁣ K 2 = 1.95 × 10 3 .25em .25em normalM − 2 false* n normalC normall 2 + normalC normall − → normalC normall 2 n + 1 − *thermodynamic equilibrium constant, corrected to 0.0 M ionic strength via the Davies equation and to 22 °C via the van’t Hoff equation.…”

“…The reaction between Cl – and Cl 2 leads to a charge transfer from the lone pair of Cl – into Cl 2 , resulting in the partial occupation of a σ* antibonding orbital in Cl 2 to weaken its chlorine–chlorine bond. − The transitional species, Cl n – , thus prefers to undergo nucleophilic substitution by HOCl/ClO – to form activated complexes {[ClOH···Cl···(Cl) n –Cl] − or [ClO···Cl···(Cl) n –Cl] 2– } with new O–Cl bonds formed between the oxygen atom on HOCl/ClO – and the chlorine atom on the weakened chlorine–chlorine bond. , The proposed activated complexes then form Cl 2 O and chloride ions. The more reactive Cl n – with a weaker Cl–Cl bond facilitates the transformation of Cl 2 by HOCl/ClO – to Cl 2 O.…”

“…We thus propose that chloride serves two important roles: one is to transform HOCl/ClO – to Cl 2 and the other is to react with Cl 2 to form polychloride monoanions, Cl n – ( n ≥ 3) (eq ). − *thermodynamic equilibrium constant, corrected to 0.0 M ionic strength via the Davies equation and to 22 °C via the van’t Hoff equation.…”