Supramolecular interaction of non-racemic benzimidazolium based ion pairs with chiral substrates

Abstract

A series of novel benzimidazolium-based non-racemic ionic liquids (ILs) was synthesized from low-cost chiral terpenoid alcohols and fully characterized by the use of a wide variety of techniques, such as DSC, ESI-MS, ATR FT-IR, polarimetry as well as 1H and 13C NMR spectroscopy. The ILs were investigated as chiral shift agents for the chiral recognition of racemic mixtures of Mosher's acid potassium salt by 19F NMR spectroscopy, leading to high splitting values of the CF3 signal. Supramolecular interactions between salt and H-C2 of chiral benzimidazolium cation are responsible for the chiral recognition, as was demonstrated by experimental evidences. Indeed, the enantiomeric excess value of enantioenriched substrates depends mainly on the strength of the contact ion pairs.

Benzimidazolium quaternary ammonium salts: synthesis, single crystal and Hirshfeld surface exploration supported by theoretical analysis

“…In the recent time, computational investigation has attracted the scientific community because of their useful applications in order to predict and calculate the optoelectronic properties of the newly prepared organic compound such as peptoids [22], chalcones and β-hydroxy carbonyl compounds [23,24], hydrazones [25,26], piperidone derivatives [27], functionalized esters, [28] phosphonates [29], functionalized indoles [30], monocarbonyl curcuminoids [31,32], unsymmetrical acyl thioureas [33], functionalized pyrimidines [34,35], imine-based Zwitterions [36] as well as organic salt systems [37,38]. In continuation of our recent reports on the organic salts [39][40][41][42][43] and benzozole derivatives [44][45][46], the current study is focused on the design, synthesis and characterization of benzimidazolium salts and the computational exploration of their prospective optoelectronic properties.…”