Direct Determination of Molecular Handedness via Coulomb Explosion Imaging

Multiple ionization and Coulomb explosion of molecules, molecular complexes, clusters and solid surfaces

“…Therefore, long accumulation times are required even when a high repetition rate laser (100 kHz) and an acquisition system (10 kHz) is used. In any event, the use of this method for quantitative discrimination of isotopically chiral molecules on a single-molecule basis demonstrates a great advantage of mass spectrometric detection of VMI.Recently, CEI of CHBrClF using a single X-ray photon (710 eV) from a synchrotron light source was reported by the same authors[244]. The results show that faster and more accurate determination of absolute configurations are possible as a consequence of the enhancement of coincidence events, faster fragmentations by inner shell excitation followed by Auger decay, and the suppression of linear momentum distribution broadening especially of proton compared with femtosecond laser pulses.The challenge of the use of CEI to identify chiral molecules is its application in the discrimination of enantiomer of large molecules containing several stereogenic centers.…”

“…In this case, the probability of chirality-sensitive coincidence events dramatically decreases as the number of fragment pathway increases. Pitzer et al showed that incomplete fragmentation (partial break-ups), corresponding to four-fold and even threefold coincidence events of five-atom (CHBrClF)[244] and eight-atom (CHClBrCF3) molecules[245], can also be used to identify enantiomers. In addition, the same authorsexamined site-selective excitation of chiral C*HClBr−CF3 containing two carbon atoms by varying the photon energy so that only the stereogenic carbon center C* (299.0 eV) or both carbon atoms (305.0 eV) are excited [245].…”