Stereoisomer discrimination in complexes of halogen-substituted difuranes and Li or Na cations.
The theoretical study of the stereoisomer discrimination of the 2:1 homo- and heterochiral complexes between chiral 5,5'-dihalogen bifuranes and lithium or sodium cations has been carried out using DFT methods. To understand the chiral effect produced by the introduction of a second bifurane molecule, the 1:1 complexes also have been calculated. All the 2:1 heterochiral complexes computed showed a nonplanar configuration around the metallic cation, but in the case of the homochiral complexes, the dibromo- and dichloro-bifurane systems around Na+ were quasi-planar. The nature of the interactions established between cations and bifurane systems has been analyzed by means of AIM and NBO, and correlations between the electron density topological parameters with the O...M distance and with the orbital interaction energy have been found. Stereodiscrimination is observed favoring the heterochiral complexes except for the Na+ complexes with chloro and bromo substituents in which the homochiral forms are more stable. Stereodiscrimination values correlate with the difference in electron density at the bond critical point and orbital interaction energy between homo- and heterochiral systems.
Rozas
Isabel
I
Centre of Synthesis and Chemical Biology, School of Chemistry, Trinity College Dublin, Dublin 2, Ireland. rozasi@tcd.ie
Alkorta
Ibon
I
Elguero
José
J
D002412:Cations / Q000737:chemistry; D005663:Furans / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008958:Models, Molecular; D008968:Molecular Conformation; D011789:Quantum Theory; D012964:Sodium / Q000737:chemistry*; D013237:Stereoisomerism
D002412:Cations; D005663:Furans; D046911:Macromolecular Substances; D008094:Lithium; D012964:Sodium