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Full-Text Articles in Physical Sciences and Mathematics
The Vagabond Flourine Atom Revisited: Dissociative Photoionization Of Tri- And Pentafluoropropene, Jessica K. De La Cruz
The Vagabond Flourine Atom Revisited: Dissociative Photoionization Of Tri- And Pentafluoropropene, Jessica K. De La Cruz
University of the Pacific Theses and Dissertations
Photoelectron Photoion Coincidence (PEPICO) Spectroscopy studies on two unsaturated hydrofluorocarbons (HFCs), also known as hydrofluoroolefines (HFOs), are presented here. Previously, the Sztáray group has studied the dissociation of trans-1,3,3,3-tetrafluoroprop-1-ene (ElixClean), which is a fourth-generation refrigerant and propellant and has lower global warming potential than its precursors. My study is an extension of the ElixClean study as it aims to explore how the different number of fluorine atoms impact the dissociation reactions of these molecules. Both 3,3,3-trifluoropropene (TFP) and cis-1,2,3,3,3- pentafluoropropene (PFP) are also utilized as propellants and refrigerants.Measurements were carried out with remote access to the CRF-PEPICO (combustion reactions followed …
Elephant And Anchors ‒ Photoelectron Photoion Coincidence Spectroscopy Of Small Oxygenated Molecules, Apeter Weidner
Elephant And Anchors ‒ Photoelectron Photoion Coincidence Spectroscopy Of Small Oxygenated Molecules, Apeter Weidner
University of the Pacific Theses and Dissertations
The dissociative photoionization reactions of two small, oxygenated organics, namely 1,3-dioxolane and methyl vinyl ketone, were studied by photoelectron photoion coincidence (PEPICO) spectroscopy. Experiments involving 1,3-dioxolane were carried out in the photon energy range of 9.5‒13.5 eV. The statistical thermodynamics model shows that a total of six dissociation channels are involved in the formation of three fragment ions, namely C3H5O2+ (m/z 73), C2H5O+ (m/z 45) and C2H4O+ (m/z 44), with two channels contributing to the formation of each. By comparing the results of ab initio quantum chemical calculations to the experimentally derived appearance energies of the fragment ions, the most …
Roaming Transition States And Highly Accurate Thermochemistry: A Pepico Study Of Two Small Combustion Systems, Kyle John Covert
Roaming Transition States And Highly Accurate Thermochemistry: A Pepico Study Of Two Small Combustion Systems, Kyle John Covert
University of the Pacific Theses and Dissertations
Two small combustion systems, methyl hydroperoxide (CH3OOH) and 2-propanol ((CH3)2CHOH), were studied using imaging photoelectron photoion coincidence spectroscopy (iPEPICO), which combines photoelectron spectroscopy and photoionization mass spectrometry to detect coincident photoelectron-photoion pairs. In the photon energy range of 11.4–14.0 eV, energy selected CH3OOH+ ions dissociate into CH2OOH+, HCO+, CH3+, and H3O+ ions. The lowest-energy dissociation channel is the formation of the cation of the smallest “QOOH” radical, CH2OOH+. A statistical rate model fitted to the …
I3: Isomerization Of Isomer Ions, Krisztián Gabor Torma
I3: Isomerization Of Isomer Ions, Krisztián Gabor Torma
University of the Pacific Theses and Dissertations
Photoelectron Photoion Coincidence (PEPICO) spectroscopy is a robust tool for elucidating complex unimolecular dissociation mechanisms and for determining thermochemical and kinetic data of gas-phase ion dissociations with high accuracy. In this work, the dissociative photoionization of two sets of isomeric systems were analyzed with PEPICO: 1) C7H7+ ions of toluene (Tol) and 1,3,5-cycloheptatriene (CHT), and 2) two butyl alcohol isomers, 1-butanol and isobutanol. Threshold dissociative photoionization data on these four molecules of interest were collected on the imaging PEPICO apparatus at the VUV beamline of the Swiss Light Source. Data analysis was aided by ab initio calculations and Rice-Ramsperger-Kassel-Marcus (RRKM) …