Fragmentation of Energy Selected CFC-1X ions
Poster Number
30
Introduction/Abstract
Diethyl ether (DEE) is a common, organic molecule widely used as a solvent, engine starting fluid, and as an octane and oxygen enhancer in internal combustion engines. DEE has also been known to become unstable and spontaneously form peroxides in air, which makes the oxidation mechanism of DEE of interest. Thermochemical input parameters have been shown to be a major source of uncertainty in combustion models, spurring us to revisit the dissociative photoionization to confirm or revise the enthalpies of formation.
Purpose
To confirm or revise the previously published and currently used ionization energy of DEE and enthalpies of formation of DEE and its daughter ions.
Method
In this study, DEE is analyzed using imaging photoelectron photoion coincidence spectroscopy (iPEPICO) at the Swiss Light Source (SLS) in Villigen, Switzerland. Quantum chemical calculations using the B3LYP/6-311++G(d,p) level of theory and G4, CBS-APNO, DFT, and STQN methods were used to determine internal energy distributions and transition states of the fragment ions. The heats of formations and fragmentation pathways were determined through RRKM modeling methods.
Results
Through thermochemical calculations, we conclude that the previous published IE of DEE by Botter et al, rather than the NIST IE value, is correct and that the vertical and adiabatic IE coincide. Enthalpies of formation and appearance energies of DEE fragments were also determined and compared to existing values.
Significance
Values have been determined for enthalpies of formation and appearance energies of DEE and its fragments and are used to either confirm or revise existing values.
Location
DeRosa University Center, Stockton campus, University of the Pacific
Format
Poster Presentation
Fragmentation of Energy Selected CFC-1X ions
DeRosa University Center, Stockton campus, University of the Pacific
Diethyl ether (DEE) is a common, organic molecule widely used as a solvent, engine starting fluid, and as an octane and oxygen enhancer in internal combustion engines. DEE has also been known to become unstable and spontaneously form peroxides in air, which makes the oxidation mechanism of DEE of interest. Thermochemical input parameters have been shown to be a major source of uncertainty in combustion models, spurring us to revisit the dissociative photoionization to confirm or revise the enthalpies of formation.
