Thèses

Jeudi 20 Octobre 2016 à 14h30.

Synthesis and reactivity of bare and ligated small metal complexes

''We describe the development of a new laser ablation nanocluster source which couples laser vaporization with electrospray ionization. With it we are able to produce many new species of metal clusters and study them with mass spectrometry, as well as investigate their reactivity in the gas phase. Stoichiometries of new species are investigated as a function of electrospray plume composition. We find that the presence of thiol ligands in the electrospray inhibits the oxidation of metal clusters in the atmosphere. Additionally, the stability and fragmentation patterns of bare metal clusters and their oxides, are investigated, with emphasis on differences and similarities between gold and silver, both for anions and cations. Fragmentation patterns of ligated complexes of the copper-group metals are studied as well and compared to the wet chemistry synthesis. By additional modification of the experimental setup, we are able to study gas phase reactivity of copper and nickel group metals with CO and NO. Simple adsorption of CO to metal clusters is observed, as well as some chemical reactions. The M2+ and M2H+ (M=Ag, Au, Pd, Pt) complexes are examined in detail in terms of reactivity and the role of hydrogen in stabilization of the complex.''