Degree Name

Master of Science – Research


School of Chemistry


Small nitrogen containing heteroaromatics are fundamental building blocks for many biological molecules, including the DNA nucleotides. Pyridine, as a prototypical Nheteroaromatic, has been implicated in the chemical evolution of many extraterrestrial environments, including the atmosphere of Titan. This thesis describes reactions of the three dehydro-N-pyridinium radical cation isomers with a set of small, unsaturated hydrocarbons: propene, acetylene, ethene and propyne. These reactions were chosen due to their possible involvement in molecular-weight growth processes, and in the synthesis of complex organics in space. Mass spectrometric techniques are used to acquire product mass spectra, measure product branching ratios and calculate second-order rate coefficients for reactions of 2-dehydro-N-pyridinium, 3-dehydro-N-pyridinium and 4- dehydro-N-pyridinium with each neutral hydrocarbon co-reactant. Quantum chemical calculations are used to validate experimental results and elucidate possible reaction mechanisms for the propene and acetylene reaction systems. Potential energy schemes are presented, together with a quantum state counting kinetic modelling analysis for propene reactions.



Unless otherwise indicated, the views expressed in this thesis are those of the author and do not necessarily represent the views of the University of Wollongong.