Enantiomeric discrimination of chiral organic salts by chiral aza-15-crown-5 ether with C1 symmetry: experimental and theoretical approaches

Kocakaya, Safak OzhanTurgut, YilmazPirinccioglu, Necmettin2024-04-242024-04-2420151610-29400948-5023https://doi.org/10.1007/s00894-015-2604-6https://hdl.handle.net/11468/14549The work involves an experimental (H-1 NMR) and theoretical (MD, MM-PBSA and DFT) investigation of the molecular recognition and discrimination properties of a chiral aza-15-crown-5 against methyl esters of alanine, phenylalanine and valine hydrochloride salts. The results indicate that the receptor binds enantiomers with moderate binding constants (88-1,389 M-1), with phenylalanine being more discriminated. The difference in experimental binding free energies (Delta G(R) - Delta G(S)) for alanine, phenylalanine and valine enantiomers were calculated as -0.36, -1.58 and 0.80 kcal mol(-1), respectively. The differences in theoretical binding energies were calculated by MM-PBSA (Delta E-PB(R) - Delta E-PB(S)=) as -0.30, -1.45 and 0.88, by B3LYP/6-31+G(d) as -1.17, -0.84 and 0.74 and by M06-2X/6-31+G(d) as -1.40, -3.26 and 1.66 kcal mol(-1). The data obtained give valuable information regarding the molecular recognition mode of the organoammonium complexes of chiral aza-crown ether with C-1 symmetry, which may be relevant to biological systems.eninfo:eu-repo/semantics/closedAccessEnantiomeric DiscriminationChiral Aza-Crown EtherMolecular RecognitionAmino Acid Ester SaltH-1 Nmr TitrationComputational CalculationMolecular DynamicsMm-PbsaDftEnantiomeric discrimination of chiral organic salts by chiral aza-15-crown-5 ether with C1 symmetry: experimental and theoretical approachesEnantiomeric discrimination of chiral organic salts by chiral aza-15-crown-5 ether with C1 symmetry: experimental and theoretical approachesArticle213WOS:0003499709000192-s2.0-849233478842570108710.1007/s00894-015-2604-6Q2Q3