DUGi

Influència de factors estructurals i electrònics sobre l’activitat catalítica, les propietats espectroscòpiques i electroquímiques en la síntesi de complexos de ruteni amb lligands dmso

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In this final degree project, ruthenium complexes with different types of polypyridyl ligands, dmso and chlorine have been synthesized and characterized, with the aim of evaluating their catalytic activity in the coupling of alcohols and the possibility of acting as antitumor agents. These compounds have been obtained from a first synthesis of the compound cis-Cl- [RuCl2(O-dmso)(S-dmso)3], [1], from the reagent RuCl3·3H2O and reflux dimethyl sulfoxide. Once this complex has been obtained, a second synthesis is carried out where the compound [1] is irradiated with visible light, with a xenon lamp at room temperature and under an atmosphere of N2, to form the compound trans-Cl-[RuCl2(O-dmso)(S-dmso)3], [2]. On the other hand, other syntheses have been carried out where the compound [1] is reacted with three different polypyridylic ligands. In a first synthesis, the reaction of [1] with the bpy ligand generates the compound [RuCl2(bpy)(S-dmso)2], [3], obtained as a mixture of cis+trans-Cl isomers. Similarly, the coordination of the bpy-Me ligand forms the two isomers cis+trans-Cl-[RuCl2(bpy-Me)(S-dmso)2], [4] and the reaction with the terpy ligand generates cis+trans-Cl-[RuCl2(terpy)(dmso)], [5]. In order to study and characterize the properties of the synthesized compounds, spectroscopic (NMR, UV-vis), spectrometric (ESI-MS) and electrochemical (cyclic voltammetry) techniques have been used. Compounds [3]-[5] show, in UV-vis, metalligand charge transfer bands, which are more energetic in the case of compounds [3] and [4], with two dmso ligands, due to the π-acceptor effect of this ligand. This effect is also evident in the E1/2 redox potential values for RuIII/RuII pairs, which are higher in these two complexes. Compounds [2], [3], [4] and [5] have been evaluated as catalysts in alcohol coupling reactions, in thermal catalysis at different temperatures and photocatalysis by exposure to white light at room temperature. A primary alcohol, such as benzyl alcohol, and a secondary alcohol (1-phenylethanol) have been used as substrates. The coupling product has been quantified by gas chromatography using biphenyl as an internal standard, and the conversion percentage and selectivity of the different complexes have been calculated in order to compare the catalytic activity between different ligand type isomers and catalysis conditions

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