Synthesis, electrochemical, biological and catalytical studies of half-sandwich Ru(II)-NSHC complexes bearing benzothiazol-2-ylidene

Abstract

The half-sandwich ruthenium(II)-NSHC complexes (2a-l) bearing benzothiazol-2-ylidene were synthesized by in situ deprotonation of N-substituted benzothiazolium salts (1a-l) with Ag2O and of [(p-cymene)Cl2Ru]2, in dichloromethane under mild conditions. However, 1m and 1n under the same conditions gave N-coordinated Ru (II) complex (3). The structures of the compounds were elucidated by NMR, FT-IR, UV-Vis, HR-MS spectroscopic methods and elemental analysis. In addition, the structures of 2k and 3 were studied by X-ray crystallography. The electrochemical properties of the complexes were investigated. Ru(II)-NSHC complexes have been used as catalysts in the transfer hydrogenation of carbonyls to secondary alcohols in the presence i-PrOH/KOH. Additionally, the effects of structural differences arising from different alkyl groups on the nitrogen atom in the benzothiazole skeleton in Ru(II)-NSHC complexes on anticancer, antifungal and antimicrobial activity were also examined.