| Summary: | <p>Gas-phase metal ion-molecule complexes provide model environments within which to study fundamental molecular interactions involved in ligand activation and metal ion solvation. These complexes also represent entrance-channel species for catalytic reactions. The ligand of interest in this thesis is nitrous oxide, which accounts for 5% of anthropogenic emissions and is a potent greenhouse gas with a warming potential 300 times greater than carbon dioxide. Thus, there is considerable interest in reducing N<sub>2</sub>O emissions particularly via metal-catalysed N<sub>2</sub>O reduction. M<sup>+/0/-</sup>(N<sub>2</sub>O)<sub>n</sub> complexes represent entrance-channel species for such reactions and yet, little attention has been given to the structures of M<sup>+/0/-</sup>(N<sub>2</sub>O)<sub>n</sub> complexes. This thesis presents the first experimental investigation on M<sup>+</sup>$(N<sub>2</sub>O)<sub>n</sub> and M<sup>+</sup><sub>n</sub>(N<sub>2</sub>O) complexes studied via infrared action spectroscopy. The infrared spectra are further interpreted and assigned from simulated spectra based on density functional theory (DFT). A range of M<sup>+</sup>(N<sub>2</sub>O)<sub>n</sub> complexes (M = group 11, group 9, and Li, Al) have been studied in an attempt to draw comparisons between the different M<sup>+</sup> electron configurations d<sup>10</sup>, d<sup>8</sup>, and closed s-shell, respectively). Spectroscopic signatures for N- and O-bound N<sub>2</sub>O ligands are observed in all cases however the importance of low-lying electronic states is revealed for the group 9 cations, and insertion complexes inferred for the Li<sup>+</sup> ion. </p> <p>Infrared multi-photon dissociation (IRMPD) studies on M<sup>+</sup><sub>n</sub>(N<sub>2</sub>O) complexes (M = Au, Co) also present N- and O-bound spectroscopic signatures. However, as the metal cluster size increases, N<sub>2</sub>O binds preferentially via the terminal N-atom. Larger clusters represent a more effective energy "bath" facilitating annealing to the lowest energy structure.</p>
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