Resumen de Experimental and computational studies on the catalytic and luminescent properties of ni, pd and au complexes with 2-chalcone or 2-biaryl phosphines
The work developed in this Thesis entails the design and synthesis of new phosphine ligands. These phosphines show either a 2-chalcone or a 2-biaryl moiety, where their fluorination degree modulates their electronic properties. The new ligands have been employed in different systems in combination with transition metals in order to study different topics such as metal-ligand interactions, reaction mechanism, catalysis or luminescent properties. The 2-chalcone phosphines (PEWO) have been identified as excellent promoters of the reductive elimination step both with Ni and Pd. This ability has been exploited to develop a Negishi catalysis to synthetize symmetric and non-symmetric highly fluorinated biaryls under mild conditions with excellent yields and great selectivity. The selectivity of this process can be further enhanced by means of a bimetallic Pd/Cu system, due to the in situ generation of the nucleophile in catalytic concentrations. The development of these two catalytic systems encouraged us to design new Pd complexes with partially fluorinated aryls that could act as efficient precatalysts with easy activation. PEWO ligands, as well as some of their Pd complexes, also exhibit luminescent properties due to the fluorinated 2-chalcone moiety they have in their structure. 2-biarylphosphines have been employed to analyze the metal-ligand interaction in [AuCl(L)] complexes in combined experimental and computational studies. These phosphines also show a peculiar cyclization reaction that implies an intramolecular SNAr reaction between the P atom and the ortho C–F bond of the lower aryl, leading to luminescent fluorophosphoranes.
