Ruthenium(ii) and palladium(ii) homo- and heterobimetallic complexes: synthesis, crystal structures, theoretical calculations and biological studies

Abstract

Four Ru–Pd heterobimetallic complexes, each one in two different coordination modes (NNSS and NS) were prepared of dialkyldithiooxamidate ligands. All stable NS complexes showed anti-proliferative activity.

Structural Diversity in Cyclometalated Diiridium(III) Complexes with Bridging syn and anti μ2‐Oxamidato and μ2‐Dithioxamidato Ligands

“…We chose this new ligand to explore whether steric effects of the methyl group in proximity to the bridge would reduce the number of isomers synthesized, or whether the mixture of isomers produced could be successfully separated into isolated isomers. While diiridium complexes with μ 2 ‐dithioxamidato ligand [ anti S 2 C−CN 2 ] or [ syn S 2 C−CN 2 ] as the bridge have not been reported, the structures of diruthenium and dipalladium complexes with a substituted μ 2 ‐dithioxamidato [ anti SNC−CNS] bridge have been determined elsewhere [32,33] . Although the isomers formed could not be isolated pure, we show the remarkable structural diversity of the syn and anti isomers from X‐ray crystallography on crystals grown from isomeric mixtures containing complexes 3 a – d , 4 and 5 .…”

“…While diiridium complexes with μ 2 -dithioxamidato ligand [anti S 2 CÀ CN 2 ] or [syn S 2 CÀ CN 2 ] as the bridge have not been reported, the structures of diruthenium and dipalladium complexes with a substituted μ 2 -dithioxamidato [anti SNCÀ CNS] bridge have been determined elsewhere. [32,33] Although the isomers formed could not be isolated pure, we show the remarkable structural diversity of the syn and anti isomers from X-ray crystallography on crystals grown from isomeric mixtures containing complexes 3 a-d, 4 and 5. The syn isomers of μ 2oxamidato-bridged diiridium systems are reported here for the first time.…”

Investigating the Cytotoxicity of Ru(II) Polypyridyl Complexes by Changing the Electronic Structure of Salicylaldehyde Ligands

“…On the basis of our ongoing research work dealing with Ru-based complexes, , we determined to evaluate this newly synthesized panel of compounds as anticancer agents. Specifically, we employed two leukemic cell lines well established in our previous works, namely CCRF-CEM (drug-sensitive) and CEM/ADR5000 (CCRF-CEM multidrug-resistant subcell line).…”

“…Two auxiliary salicylaldehyde ligands with different pattern of substitution and the starting Ru­(phen) 2 Cl 2 complex were selected as controls. We did not use the standard Ru-based complex NAMI-A as a positive control as our previous studies demonstrated that this compound exerts negligible cytotoxic effects against the two selected leukemic cell lines Figure shows the screening results sorted by decreasing cell viability (waterfall plot).…”

Antiproliferative Properties of a Few Auranofin-Related Gold(I) and Silver(I) Complexes in Leukemia Cells and their Interferences with the Ubiquitin Proteasome System

“…Based on these arguments, we have further explored whether a selected group of metal compounds might contrast the growth of leukemia cells in vitro as well as inhibit potently and selectively the main protease activities of the proteasome. Previous results showed that, in general, metal-based compounds endowed with anticancer activity may behave as strong proteasome inhibitors [ 14 , 15 , 16 ]. In particular, pertaining to anticancer gold derivatives, we reported that a group of gold(III) complexes and a gold(I) phosphine complex caused profound and differential inhibition of this target, at variance with the reference compound AF, which turned out to be nearly ineffective [ 17 ].…”