Enantioselective femtosecond laser photoionization spectrometry of limonene using photoelectron circular dichroism

Limonene is ionized by circularly polarized 420 nm femtosecond laser pulses. Ion mass and photoelectron energy spectra identify the dominant (2 + 1) multiphoton ionization mechanism, aided by TDDFT calculations of the Rydberg excitations. Photoelectron circular dichroism measurements on pure enantiomers reveal a chiral asymmetry of ±4 %. Circularly polarized, femtosecond laser multiphoton ionization can clearly distinguish between the enantiomers of limonene from a 4% chiral asymmetry in the photoelectron angular distribution.