Synthetic Strategy Towards Heterodimetallic Half-Sandwich Complexes Based on a Symmetric Ditopic Ligand

Abstract

Multimetallic complexes have been shown in several examples to possess greater anticancer activity than their monometallic counterparts. The increased activity has been attributed to altered modes of action. We herein report the synthesis of a series of heterodimetallic compounds based on a ditopic ligand featuring 2-pyridylimine chelating motifs and organometallic half-sandwich moieties. The complexes were characterized by a combination of 1H NMR spectroscopy, electrospray ionization mass spectrometry, elemental analysis and single crystal X-ray diffraction. Investigations into the stability of representative complexes in DMSO-d6 and 10% DMSO-d6/D2O revealed the occurrence of solvent-chlorido ligand exchange. Proliferation assays in four human cancer cell lines showed that the Os-Rh complex possessed minimal activity, while all other complexes were inactive.

Synthesis and studies of aqueous-stable diruthenium aminocarbyne complexes uncovered an N-indolyl derivative as a prospective anticancer agent

“…We redirected our focus towards developing a similar biochemistry to the commercially available [Ru 2 Cp 2 (CO) 4 ], which has not been explored hitherto. Note that the "diruthenium approach" has garnered increasing attention in medicinal chemistry, [28][29][30][31][32][33][34][35] nevertheless investigations on the anticancer potential of compounds with a Ru-Ru bonded core remain quite limited. Contributing to this field, we have recently unveiled the activity of [Ru 2 Cp 2 (CO) 4 ] derivatives containing bridging allenyl 36 and vinyl ligands.…”

Hydrazone- and imine-containing [PdPtL4]4+ cages: a comparative study of the stability and host–guest chemistry

“…To the best of our knowledge, the cytotoxicity of heterobimetallic [PdPtL 4 ] 4+ architectures have not yet been studied, however others have reported mixed metal assemblies and the influence two different metals have on cytotoxicity. 34–37…”