Catecholase-Like Activity and Theoretical Study in Solid State of a New Ru(III)-Schiff Base Complex

Abstract

A new ruthenium(III) complex of molecular formula [Ru(PPh3)Cl2(L)] (1) has been synthesized using the Schiff base ligand obtained from 5-chlorosalicylaldehyde and N,N-dimethylethylenediamine and characterized by FT-IR, UV-Vis, cyclic voltammetry and single crystal X-ray structural analysis. The metal ion exhibits a slightly distorted octahedral environment where the chelating Schiff base ligand contributes with its NNO donor set. The coordination geometry around the Ru(III) ion is completed by a PPh3 ligand and two chloride anions, and the charge balance is assured by the phenoxo oxygen of the Schiff base. With the aim to analyse the energy related to the halogen bonding interactions in solid state, a theoretical study has been performed on complex 1, by using the MEP and NCl plot computational tools. Furthermore, complex 1 shows catecholase-like activity in conversion of the model substrate 3,5-di-tert-butylcatechol (3,5-DTBC) to the corresponding 3,5-di-tert-butylquinone (3,5-DTBQ) under aerobic condition. The parameters regarding the enzymatic kinetics have been evaluated from the Lineweaver-Burk plot using the Michaelis-Menten approach of enzyme catalysis. A significant high T.O.N value (2.346 × 103 h–1) indicates that complex 1 has a very good catalytic efficiency towards 3,5-DTBC.