Summary: | <p>Metal-containing clusters and complexes may represent active sites in heterogeneous catalysts, where catalytic transformations take place, thus offering an elegant approach in studying the fundamental interactions in a simplified way. In this thesis, infrared-(multiple) photodissociation spectroscopy is used to study metal-containing clusters and complexes with atmospherically relevant adsorbates to learn about their reactivity, structural binding motifs, and the degree of activation of adsorbed moieties. Complementary density functional theory calculations help in the assignment of experimentally observed phenomena.</p>
<p>Each chapter describes a different system that presents unique and sometimes unexpected results. N2O binding to Pt+n proves to be size-dependent; small clusters form molecular N2O adsorption products whereas larger ones react to produce PtO+, and similar chemistry is observed upon infrared excitation. Examining N2O binding to Au+n and Co+n reveals inertness of gold clusters whereas cobalt species prove to be similar in their reactivity to platinum. Size-selective cooperative binding effects are discovered for AunO2CO− species both from mass spectrometry and spectroscopy. Infrared action spectra of Co(NO)+n and Rh(NO)+n complexes disclose spectral differences in the number and position of the bands as well as similarities in the NO binding motifs to these metal centres. Rh(CO)n(N2O)+m system proves to be different than Au(CO)n(N2O)+m studied by the Mackenzie group previously, and these observations are explained in terms of different electronic structures, relative binding energies, and coordination numbers. Isotopic study of Au(CO)n(N2O)+m using 13CO reveals a band in the infrared spectrum of the Au(12CO)2(N2O)+ complex that is an overlap between individual 12C≡O and N2O N=N vibrational bands.</p>
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