Synthesis of a chromophore‐catalyst dyad ruthenium complex for oxidation reactions

Abstract

In this work, we present the synthesis, spectroscopic and redox characterization of a new chromophore‐catalyst dyad ruthenium compound, (Rup‐Ruc‐Cl), linked by a bridging polypiridyl ligand (trpy‐ph‐trpy). A preliminary study of it catalytic behaviour in the photo‐oxidation of 1‐ phenylethanol in aqueous medium is also presented. The system consists of a catalyst based on a ruthenium chlorocomplex [RuCl (R‐trpy)(bpy)] 2+ (RuII‐Cl, Ruc) and a chromophore which absorbs light in the visible spectrum, [Ru (trpy)(R‐trpy)] 2+(Rup). Both compounds share the bridging ligand (trpy‐ph‐trpy). Two synthetic pathways have been carried out to obtain this compound : 1) First, it has been carried out the synthesis of catalyst [RuIICl(trpy‐ph‐trpy)(bpy)]+ (Ruc‐Cl) [3] by the reaction of bridging ligand (trpy‐ph‐trpy) with cis (Cl),cis (S)‐[RuCl2(DMSO‐S)2] [2]. Then, the complex Ruc IICl [3] reacts with [RuIII(trpy)Cl3] [4], to obtain the final complex Rup‐Ruc‐Cl [5]. In another synthetic patway, 2), first, it is carried out the synthesis of chromophore [RuII(trpy)(trpy‐ph‐trpy)]2+(Rup) [7] by the reaction of [RuII(trpy)(DMSO)Cl2] [6] with the bridging (trpy‐ph‐trpy) ligand. Then, compound [7] reacts with cis(Cl),cis(S)‐ [RuIICl2(bpy)(DMSO‐S)2] [2] to obtain the final complex Rup‐Ruc‐Cl [5]. The characterization of complexes have been carried out in solid state through elemental analysis and infrared spectroscopy (IR) and in solution by spectroscopic techniques such as nuclear magnetic resonance (NMR) and ultraviolet visible (UV‐Vis).The redox characterization has been done by cyclic voltammetry (CV). Finally, it has been evaluated the catalytic activity of the compound Rup‐Ruc‐Cl [5], in the photooxidation reaction of 1‐phenylethanol in aqueous medium