Abstract

This PhD thesis focuses on the fragmentation mechanism of the furan molecule in the gas phase. The approach taken in this work comprised of three theoretical methodologies considering the dynamical, energetical and entropic aspects of the studied process. First, molecular dynamics simulations were performed. Next, the potential energy surfaces were explored at the DFT/B3LYP level of theory. Finally, a new statistical Microcanonical Metropolis Monte Carlo method was employed. In this work it has been concluded that the fragmentation mechanism differs depending on the ionization state of the molecule. Decomposition mechanism of the neutral molecule required hydrogen transfer before the fragmentation. Exploration of the potential energy surface of the singly ionized furan confirmed that cleavage of the C-O bond is the first step of the fragmentation process. Obtained results were compared with experimental measurements. Analogies between calculated energy barrier heights and measured Appearance Energies confirmed the most probable fragmentation mechanisms. Next important result of this work relied on calculation of the energy deposition functions by fitting the experimental mass spectra and the theoretical breakdown curves.

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