Upper limits for the circular dichroism for the C 1s and O 1s core excitation of methyl oxirane

Abstract

The circular dichroism in the total and partial ion yields of methyl-oxirane C 3 H 6 O was measured at the C 1s and O 1s edges. The difference of the response of the chiral molecule to circularly polarized light with opposite handedness was found to be less than 0.2% for the total ion yield and less than 0.5% for the partial ion yield. Additionally we tried to find a dipole allowed molecular orientation CD effect by analyzing the fragmentation in the forward and backward direction. For this effect we found an upper limit of 1-2% for all abundant ionic fragments.

Double photoionization of propylene oxide: A coincidence study of the ejection of a pair of valence-shell electrons

“…14,15 Such a study is being extended in our laboratory, coupling the mechanical molecular velocity selector method (permitting the control of the velocity dependence of molecular alignment) [5][6][7][8] with electronion imaging detection using tunable synchrotron radiation with high intensity. 16,17 Previous studies on propylene oxide, performed by exploiting Auger spectroscopy, indirectly estimated the first double ionization threshold, 18,19 allowing the observation of a weak circular dichroism effect 19 after the pionieristic work performed by Prümper et al 20 In addition, it has to be noted that the use of propylene oxide, as a prototype chiral molecule in order to investigate the possible (C 3 H 6 O) 2+ molecular dication formation by vacuum ultraviolet (VUV) double photoionization, is of particular interest because of the recent astronomical detection of such a neutral chiral molecule in absorption toward the Galactic center. 2 The importance of the double photoionization, and of the elementary processes induced, has been demonstrated by a number of papers, in particular, by Eland and co-workers, [21][22][23] by extending Zare's approach to photodissociation.…”

Phase and ellipticity dependence of the photoelectron angular distribution in non-resonant two-photon ionization of atomic hydrogen. I

“…Spectroscopy studies based on circular dichroism are recognized as a valuable tool for investigating the structural response of chiral systems to an electromagnetic field. Such effects have been observed very recently on chiral molecules [1,2]. For non-chiral systems, it is surprising that they can also be observed in the (one-photon) double photoionization of helium atoms in their ground state [3].…”

“…142(2) −1.004(2) −3.966(1) 3.966(1) 1.004(2) we have amplified by 100 its amplitude such that one can observe the positions of the maxima and the minima which are located at φ = 45 • (225 • ) and φ = 135 • (315 • ) respectively. In figure3(b), all the distributions show two marked lobes pointing along φ = 67.5 • (257.5 • ) for ζ = 20 • and 40 • , while the distribution for ζ = 60 • is along φ = 165 • (345 • ).…”