<b>The accepted concept behind relative intensities in a mass spectrometry experiment correlates to relative stability of ionic fragments of the system in question. If true, the relative stability should be able to be produced via ab initio computational studies. To investigate this phenomena, we studied butane, isobutane, and propanol and their cationic fragments. These small chained hydrocarbons and a small alcohol were chosen for simplicity and to minimize the potential for rearrangement. A range of computational studies were carried out to investigate the process that takes place inside a typical ionization mass spectrometer. All systems of interest were characterized via coupled-cluster theory. Calculations were carried out with the CFOUR computational program package. The standard ionization energies were calculated and compared to experimental results. Harmonic frequencies were calculated to account for the zero-point vibrational energy and confirm a minimum on the potential energy surface for the optimized geometries. Standard thermodynamic properties (entropy, enthalpy, and free energy) were computed at higher temperatures to get a qualitative picture of the stability of the fragments. </b>

Characterization of the mass spectra energetics of butane and propanol derivatives via <i>ab initio</i> methods

255th National Meeting (2018)

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Characterization of the mass spectra energetics of butane and propanol derivatives via ab initio methods