Synthesis and Characterization of a New Racemic Helically Chiral Ru(II) Complex and Its Catalytic Degradation of Eriochrome Blue Black B

Abstract

A new helically chiral ruthenium complex of fused aromatic rings was prepared in a one stepsequence and fully characterized. The new complex was used as an heterogeneous catalyst for the degradation of Eriochrome Blue Black B (one of the azoic dyes) in aqueous medium in the presence of hydrogen peroxide. Using a fixed dose of H₂O₂, experiments revealed that the dye degradation was affected by 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 (31 kJ mol⁻¹), confirming that the prepared catalyst was very efficient for the degradation of anionic dyes using H₂O₂. The complex exhibited excellent catalytic activity and has the advantage of easy separation from the reaction medium. In addition, the ruthenium helical complex–H₂O₂ system could remain with good catalytic activity after five cycles.

GRAPHICAL ABSTRACT

Keywords:

• Azoic dyes
• catalysis
• dye degradation
• eriochrome blue black B
• helical complexes
• helicenes

ACKNOWLEDGMENT

The authors are grateful to the Direction Générale de la Recherche Scientifique of the Tunisian Ministry of Higher Education and Scientific Research for financial support.