Environmental-confinement-induced stability enhancement of chiral molecules

We computationally study the transition process of a chiral difluorobenzo[ c]phenanthrene (DFBcPh) molecule within nonpolar fullerene C₂₆₀ to explore the confinement effect. We find blue-shifts in the infrared and Raman spectra of the molecule inside the fullerene relative to those of isolated systems. Six types of spectrum features of the molecule appear in the 0-60 cm^-1 band. Interestingly, the energy barrier of the chiral transformation of the molecule is elevated by 15.88 kcalmol^-1 upon the confinement by the fullerene, indicating improvement in the stability of the enantiomers. The protection by C₂₆₀ lowers the highest occupied molecular orbital energy level and lifts the lowest unoccupied molecular orbital energy level of the chiral molecule such that the chiral molecule is further chemically stabilized. We concluded that the confinement environment has an impact at the nanoscale on the enantiomer transformation process of the chiral molecule.