Chiral recognition of propranolol enantiomers by chiral ionic liquid: A quantum chemical calculation analysis

• Published in: Computational and theoretical chemistry 2018-09, Vol.1140, p.38-48
• Main Authors: Sedghamiz, Tahereh, Ghalami, Farhad, Sedghamiz, Elaheh, Bahrami, Maryam
• Format: Article
• Language: English
• Subjects: Chiral ionic liquids; Chiral recognition; Hydrogen bonds; Propranolol enantiomers
• ISSN: 2210-271X
• DOI: 10.1016/j.comptc.2018.07.017

[Display omitted] •The [BMIm+] [BSMB] IL was employed as a chiral selector for recognition of propranolol enantiomers.•The S-Pr/IL complex is energetically more favorable in accordance with experimental results.•IL’s anion forms strong H-bonds with propranolol in S-Pr/IL complex.•IL’s cation contributes to weak H-bond and π-stacking interactions in S-Pr/IL complex. Electronic structure and noncovalent interactions of the complexes of 1-butyl-3-methylimidazolium (T-4)-bis[(αS)-α-(hydroxy-O)benzeneacetato-κO] borate ionic liquid (IL) with propranolol hydrochloride enantiomers are analyzed using hybrid M06-2X density functional theory. Based on the binding energies, the S-Propranolol/IL (S-Pr/IL) complex is more stable than the R-Propranolol/IL (R-Pr/IL), which is in accordance with the experimental results (Absalan et al., 2012). Reduced density gradient (RDG) method, natural bond orbital (NBO) and electrostatic potential (ESP) analysis show that the intermolecular interactions in S-Pr/IL system are stronger than those in R-Pr/IL. Results of Atom in molecule (AIM) analysis indicate that two strong H-bonds and also weak π-stacking interactions are the main reason of the stability of S-Pr/IL complex. Moreover, the anion found to contribute mainly in forming the strong H-bonds and weak Van der Waals interactions with propranolol enantiomers in both studied complexes.