Ru(II)‐η6‐benzene Complexes of Dibenzosuberenyl Appended Aroyl/Acylthiourea Ligands: In vitro Biomolecular Interaction Studies and Catalytic Transfer Hydrogenation

Abstract

AbstractA series of novel N‐dibenzosuberene appended aroyl/acylthiourea ligands (L1‐L4) and their Ru(II)‐benzene complexes (1‐4), [RuCl2(η6‐benzene)L] (L=monodentate aroyl/acylthiourea ligand) was synthesized and well characterized. The coordination mode of aroyl/acylthiourea ligand with Ru ion through S (neutral monodentate) donor atom was determined by single crystal X‐ray diffraction analysis. In vitro Calf thymus DNA (CT‐DNA) and Bovine serum albumin (BSA) interaction of the complexes were investigated by UV‐Visible, fluorescence spectroscopic and hydrodynamic methods. The results showed the intercalative mode of binding (in the order of 1 > 4 > 3 > 2) of the Ru(II)‐benzene complexes with CT‐DNA. The DNA (pUC19) cleavage study showed that the complexes cleaved DNA through a hydrolytic pathway. All the complexes have been thoroughly screened for their cytotoxicity against human liver carcinoma (HepG‐2) and lung cancer (A549) cells under in vitro conditions. Complex 1 exhibited significant cytotoxic activity (IC50=46.1 μM) towards HepG‐2 cancer cell line. In addition to this, the prepared complexes have been utilized as catalyst precursors for transfer hydrogenation (TH) of ketones, aldehydes and nitro compounds using 2‐propanol as a hydrogen source. The TH reactions proceeded with exceptional conversions (up to 99%) and the present catalytic system was extended to substituted aromatic/heterocyclic carbonyl and nitro compounds.