New Helically Chiral Metallated Complexes: Characterization and Catalytic Activity

Abstract

New helically chiral and air-stable Pd(II) and Ru(II) complexes were prepared in good yields and fully characterized. The optical properties of these new complexes were investigated, showing interesting behavior. The Ru complex was used as heterogeneous catalyst for the decoloration of calmagite (one of the azoic dyes) solutions at pH 6.5 in the presence of hydrogen peroxide (H2O2). Experiments revealed that the decoloration process was affected by the H2O2 dose, the reaction temperature, and the initial dye concentration. The energetic parameters were also determined and the activation energy, E a, was found to be low, confirming that the prepared catalyst was very efficient for color removal. The new ruthenium complex exhibited excellent catalytic activity and has the advantage of easy separation from the reaction medium. It could remain with good catalytic activity after five cycles.