Síntesi de complexos de ruteni amb lligands heterocíclics de tipus N- i C- donors per a processos catalítics d'acoblament d'alcohols

Abstract

During this final degree project, different synthetic routes have been carried out with the aim of obtaining new ruthenium complexes with different types of ligands. The set of syntheses performed have a common objective of preparing compounds capable of catalyzing alcohol coupling reactions. Five ruthenium compounds have been synthesized. Compound [1], [RuCl2(dmso)4], was synthesized from RuCl3 and dimethylsulfoxide by refluxing. Once this complex is obtained, the second synthesis is carried out, where [1] reacts with the previously synthesized ligand bpea to form cis,fac-[RuCl2(bpea)(dmso)], compound [2]. On the other hand, [RuCl3(bpea)], compound [3], has been synthesized from RuCl3·2.53H2O and the ligand bpea. Both compound [2] and compound [3] are precursor complexes of compound [4], trans,fac-[RuCl(Cb-Me)(bpea)] (PF6), which can be obtained by reacting these precursors with the bidentate ligand Cb-Me under different conditions. Finally, starting from compound [4] in an aqueous medium and adding AgNO3, the last synthesized complex is obtained, the aquacomplex [5], trans,fac-[Ru(Cb Me)(bpea)(OH2)](PF6)2. To characterize and study the different properties of the compounds obtained during the synthesis, spectroscopic, spectrometric, and electrochemical techniques such as 1H-NMR, UV Vis, ESI-MS, and cyclic voltammetry have been used. Compounds [2], [3], [4], and [5] have been evaluated as catalysts in alcohol coupling reactions, using a primary alcohol, such as benzyl alcohol, and a secondary alcohol, such as 1- phenylethanol. The studied catalyzes have been carried out under temperature (thermal catalysis) or by activation with white light (photocatalysis). The coupling product has been quantified using 1H-NMR, and the corresponding conversion percentage and turnover number (TON) of catalytic cycles have been calculated. The effectiveness of the different complexes has been compared by considering the different conditions and the structure or oxidation state of the catalysts