Search

A number of reduced amino Schiff base ligands and corresponding ruthenium(III) complexes were designed and prepared based on the fact that amino acids not only possess multiple coordinate atoms but also improve the solubility of drugs in the body. The interaction of the complexes with calf thymus DNA was analyzed with spectroscopic methods of ultraviolet‐visible absorption spectra, DNA competitive binding with ethidium bromide, circular dichroism spectra, and DNA melting experiments, and DNA viscosity measurements, indicating that the complexes bind to DNA primarily in the grooving mode. With respect to the ligands, the cytotoxicity in vitro of the complexes against Hela, A549, and MCF‐7 cells was much enhanced, with most of the IC50 values less than 50 μM or even comparable with those of cisplatin. [ABSTRACT FROM AUTHOR]

A new class of ruthenium(III) complexes containing O, N donor functionalized azo derivatives were designed and synthesized. The synthesized compounds were characterized by fourier‐transform infrared (FTIR), ultraviolet–visible (UV‐vis) and electron paramagnetic resonance (EPR) spectral studies. The X−ray crystal structure of one of the complexes [Ru(L1)3] 1 has been determined. The catalytic activity of the complex [Ru(L1)3] 1 has been studied for the oxidation of primary and secondary alcohols to corresponding carbonyl compounds in the presence of N‐ Methylmorpholine‐N‐Oxide as co‐oxidant. A new class of ruthenium(III) complexes containing O, N donor functionalized azo derivatives were designed and synthesized. The X−ray crystal structure of one of the complexes [Ru(L1)3] 1 has been determined. The catalytic activity of the complex [Ru(L1)3] 1 has been studied for the oxidation of primary and secondary alcohols to corresponding carbonyl compounds in the presence of NMO as co‐oxidant. [ABSTRACT FROM AUTHOR]

Speciations of ruthenium(III)-edta complexes of bidentate (O, O) (N, O) and (S, O) donor type ligands were determined by pH-potentiometry and UV/Vis spectrophotometry in aqueous solution. Complexes of [RuIII(edtaH x)L]2- ( x = 0, 1, 2 and 3) stoichiometry were only formed and the fully deprotonated species dominate at the physiological pH 7.4. Protonation occurs at the free carboxylate arms of edta; when x = 3 one of the coordination positions of the RuIII becomes free. Formation of protonated ternary complexes are more characteristic for ligands with (N, O) and (S, O) donor sets where the complex formation started (ligands with (N, O) donor set) or completed (ligands with (S, O) donor set) already at pH 2. In acidic conditions the stability order of the complexes follows the (O, O) < (N, O) < (S, O) sequence, which changes slightly for the physiological pH 7.4: (O, O) ≈ (N, O) < (S, O). The complexes formed were characterised also by LNT EPR spectroscopy. The kinetics of the ligand exchange between ternary complexes at pH 6 was found to be dissociative. The reaction rate follows basically the stability order: (O, O) < (N, O) < (S, O). No side reactions were found when the ligands replaced had (O, O) donor set; but formation of [RuIII(edta)(L1),(L2)]3- was hypothesised in the case of ligands with (N, O) or (S, O) donor sets. [ABSTRACT FROM AUTHOR]