UBC Theses and Dissertations
Supramolecular chemistry of palladium and platinum-containing macrocycles : from ring-expansion to host-guest complexes Carta, Veronica
Two main projects are presented in this thesis. In the first project we used ligand exchange to influence the reactivity of an unstrained palladium-containing metallomacrocycle toward ring-opening metathesis polymerization (ROMP) reaction. The ligand-exchange rate on the palladium center between acetonitrile and six different ligands was investigated for an NNN pincer bis(amido)pyridine metallomacrocycle and compared with its corresponding open form. Kinetic studies showed that the small size of the macrocycle cavity impedes ligand exchange. We then used a bulky ligand (2,6-lutidine) to provide steric hindrance, blocking ring-closing and favouring ROMP of the NNN pincer bis(amido)pyridine metallomacrocycle. The second project involves the synthesis and characterization of several Pt²⁺, Pt³⁺, and Pt⁴⁺ phenylpyridine complexes. We first used a bidentate functionalized phenylpyridine ligand, then two flexible tetradentate ligands featuring an ethylene glycol chain, and finally two preorganized tetradentate ligands, one of which contained a full crown ether functionality. The presence of the crown ether functionality makes these compounds attractive for host-guest chemistry applications. The synthetic challenges related to obtaining biscyclometalated platinum monomeric complexes with phenylpyridine-containing ligands were addressed by using different approaches: high dilution, cation coordination, and ligand preorganization. Some of the complexes prepared appear to be promising for cation recognition and for the formation of supramolecular assemblies such as rotaxanes and pseudorotaxanes.
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