Ivan Powis

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Photoionization of the chiral molecule glycidol has been investigated in the valence region. Photoelectron circular dichroism (PECD) curves have been obtained at various photon energies by using circularly polarized VUV synchrotron radiation and a velocity map imaging technique to record angle-resolved photoelectron spectra (PES). The measured chiral(More)
An electron imaging technique has been used to study the full angular distribution of valence photoelectrons produced from enantiomerically pure molecular beams of camphor when these are photoionized with circularly polarized light. In addition to the familiar beta parameter, this provides a new chiral term, taking the form of an additional cosine function(More)
In this Perspective we discuss photoelectron circular dichroism (PECD), a relatively novel technique that can detect chiral molecules with high sensitivity. PECD has an enantiomeric sensitivity of typically 1-10%, which is two to three orders of magnitude larger than that of the widely employed technique of circular dichroism (CD). In PECD a chiral molecule(More)
We have measured the photoelectron circular dichroism (PECD) of single enantiomers of endoborneol in the photon region from 9.9 to 23.6 eV by combining circularly polarized synchrotron radiation and a velocity map imaging technique. A photoelectron spectrum and the state-selected fragmentation curves of this terpene were also recorded. Unlike previous case(More)
Photoelectron circular dichroism (PECD) is investigated in the valence ionization of selected fenchone enantiomers using a photoelectron imaging technique and circularly polarized synchrotron radiation. Theoretical modelling of the results using electron scattering calculations demonstrates that the observed chiral asymmetry in the photoelectron angular(More)
The inner-shell photoionization of unoriented camphor molecules by circularly polarized light has been investigated from threshold to a photoelectron kinetic energy of approximately 65 eV. Photoelectron spectra of the carbonyl C 1s orbital, recorded at the magic angle of 54.7 degrees with respect to the light propagation direction, show an asymmetry of up(More)
Photoelectron circular dichroism (PECD), a forward-backward asymmetry along the light propagation direction observed in the angular distribution of photoelectrons formed in the ionization of a chiral gas phase target with circularly polarized light, is becoming an established technique for chiral differentiation. In this work some of the fundamental and(More)
Electron-nuclei coupling accompanying excitation and relaxation processes is a fascinating phenomenon in molecular dynamics. A striking and unexpected example of such coupling is presented here in the context of photoelectron circular dichroism measurements on randomly oriented, chiral methyloxirane molecules, unaffected by any continuum resonance. Here, we(More)
The photoelectron circular dichroism that arises in the angular distribution of photoelectrons emitted from the carbonyl group in randomly oriented pure enantiomers of carvone, and a number of carvone derivatives, is investigated by continuum multiple scattering calculations. Core ionization of carbonyl C 1s orbitals is examined for six different(More)
Measurements made with a dilute, non-oriented, gas-phase sample of a selected fenchone enantiomer using circularly polarized synchrotron radiation demonstrate huge chiral asymmetries, approaching 20%, in the angular distribution of photoelectrons ejected from carbonyl C 1s core orbitals. This asymmetry in the forward-backward scattering of electrons along(More)