Synthesis, Characterization and Anticancer Studies of Rh(I), Rh(III), Pd(II) and Pt(II) Complexes Bearing A Dithiooxamide Ligand

Abstract

Breast cancer is the most common type of cancer in women. In the current study, six transition‐metal complexes were reacted with a secondary dithiooxamide (H2‐isopropyl2DTO) to obtain the corresponding mononuclear complexes (1‐6) and their cytotoxicity was evaluated in two human breast cancer cell lines, i. e. MCF‐7 and MDA‐MB‐231. The characterization of the complexes, [LnM(H‐isopropyl2 DTO κ‐S,S M)] (LnM=(C5Me5)RhCl, (1); (COD)Rh, (2); (η3‐allyl)Pd, (3); (trinpropyl‐phosphine)PdCl, (4); (bpy)Pt, (5) and (pph3)PtCl, (6)), and the ion pair form of 1–4, IP1‐IP4, were accomplished through NMR spectroscopy and elemental analysis. The structures of 1 and IP1 were also determined by single crystal XRD technique. In vitro cytotoxicity studies in MCF‐7 and MDA‐MB‐231 (IC50 determination) showed that all complexes are cytotoxic for both cell lines, with the exception of 2. Compound 3 was the most cytotoxic in the conditions tested. In addition, the compounds induce cell death by apoptosis and inhibit the formation of colonies, indicating that these compounds could provide promising new lead derivatives for anticancer drug development.

Halogen-Bonding-Mediated Radical Reactions: The Unexpected Behavior of Piperazine-Based Dithiooxamide Ligands in the Presence of Diiodine

“…The planarity of two thioamide moieties is indicative of an sp 2 2) and 1.325(2) Å) 26 as well as in other analogous noncyclic ligands and in many transition-metal dithiooxamide complexes where the ligand acts as a neutral bidentate donor group. 27,28 Therefore, the two N−C−S groups can be better described as an admixture of thiol and thione resonance structures.…”

“…Dithiooxamides are well-known organic ligands largely employed in coordination chemistry for a long time thanks to the peculiar electronic properties and coordination versatility of the two vicinal thioamidic moieties. − Despite the variety of interactions they can give rise to with metallic and nonmetallic species, dithiooxamides typically work as soft S-donors toward acceptors such as soft metal cations and halogens. − The acceptor capability of the electron density of halogens from a neutral or anionic Lewis base is well recognized as a noncovalent attractive interaction involving a halogen as an acceptor to form adducts . This capability has also been elucidated by quantum mechanical methods giving rise to the widely accepted σ-hole model. , In several cases, these adducts are stable in solution and can be isolated also in the solid state, while elsewhere the system further evolves to give redox products.…”