Absolute photoionization cross sections of two cyclic ketones: cyclopentanone and cyclohexanone

Abstract

Absolute photoionization cross sections for cyclopentanone and cyclohexanone, as well as partial ionization cross sections for the dissociative ionized fragments, are presented in this investigation. Experiments are performed via a multiplexed photoionization mass spectrometer utilizing vacuum ultraviolet (VUV) synchrotron radiation supplied by the Advanced Light Source of Lawrence Berkeley National Laboratory. These results allow the quantification of these species that is relevant to investigate the kinetics and combustion reactions of potential biofuels. The CBS-QB3 calculated values for the adiabatic ionization energies agree well with the experimental values, and the identification of possible dissociative fragments is discussed for both systems. Copyright © 2017 John Wiley & Sons, Ltd.

Investigation on the absolute and relative photoionization cross sections of 3 potential propargylic fuels

“…Multiplexed time‐resolved synchrotron PIMS experiments are performed at the Chemical Dynamics beamline (9.0.2) of the Advanced Light Source at the Lawrence Berkeley National Laboratory. The details of this experiment have been described before in detail and will only be discussed briefly here …”

Determination of highest occupied molecular orbital and cationic structures of cyclopentanone using high‐resolution vacuum ultraviolet mass‐analyzed threshold ionization mass spectrophotometry

“…1,2 In addition, since CP is a precursor for synthesizing fragrances, pharmaceuticals, and biologically active compounds, 3,4 its conformational structure and conformation-dependent reactivity have been investigated by various means. [5][6][7][8][9][10][11][12] It is known that CP exists at equilibrium as a twisted conformer with C 2 symmetry, and conformer interconversion occurs via pseudorotational or twisting motions. 5,6 Furthermore, it was proposed that interconversion between the twisted conformers occurs preferentially along the pseudorotational coordinate associated with the envelope transition conformation at the lower barrier of approximately 750 cm À1 rather than via the planar hilltop conformation (C 2V symmetry) at the higher barrier of approximately1400 cm À1 .…”

“…Subsequently, photoelectron spectroscopy and laser-induced ionization/dissociation techniques have been performed with the aim of understanding the mechanism of fragmentation via ring opening for the CP ion. [7][8][9][10][11][12] However, different dissociation pathways corresponding to the m/z = 56 products (C 3 H 4 O + and C 4 H 8 + ) of the CP cation were proposed. Thus, the details of the ionization/dissociation mechanisms regarding the formation of a CP fragment ion remain poorly understood.…”

“…Cyclopentanone (CP), which can be easily synthesized from furfural via one‐step hydrogenation, has received significant attention from the alternative fuel industry 1,2 . In addition, since CP is a precursor for synthesizing fragrances, pharmaceuticals, and biologically active compounds, 3,4 its conformational structure and conformation‐dependent reactivity have been investigated by various means 5–12 . It is known that CP exists at equilibrium as a twisted conformer with C 2 symmetry, and conformer interconversion occurs via pseudorotational or twisting motions 5,6 .…”

“…Furthermore, it was proposed that interconversion between the twisted conformers occurs preferentially along the pseudorotational coordinate associated with the envelope transition conformation at the lower barrier of approximately 750 cm −1 rather than via the planar hilltop conformation ( C 2V symmetry) at the higher barrier of approximately1400 cm −1 . Subsequently, photoelectron spectroscopy and laser‐induced ionization/dissociation techniques have been performed with the aim of understanding the mechanism of fragmentation via ring opening for the CP ion 7–12 . However, different dissociation pathways corresponding to the m / z = 56 products (C 3 H 4 O + and C 4 H 8 + ) of the CP cation were proposed.…”