Selenoquinones Stabilized by Ruthenium(II) Arene Complexes: Synthesis, Structure, and Cytotoxicity

Abstract

A new series of monoselenoquinone and diselenoquinone π complexes, [(η(6) -p-cymene)Ru(η(4) -C6 R4 SeE)] (R=H, E=Se (6); R=CH3 , E=Se (7); R=H, E=O (8)), as well as selenolate π complexes [(η(6) -p-cymene)Ru(η(5) -C6 H3 R2 Se)][SbF6 ] (R=H (9); R=CH3 (10)), stabilized by arene ruthenium moieties were prepared in good yields through nucleophilic substitution reactions from dichlorinated-arene and hydroxymonochlorinated-arene ruthenium complexes [(η(6) -p-cymene)Ru(C6 R4 XCl)][SbF6 ]2 (R=H, X=Cl (1); R=CH3 , X=Cl (2); R=H, X=OH (3)) as well as the monochlorinated π complexes [(η(6) -p-cymene)Ru(η(5) -C6 H3 R2 Cl)][SbF6 ]2 (R=H (4); R=CH3 (5)). The X-ray crystallographic structures of two of the compounds, [(η(6) -p-cymene)Ru(η(4) -C6 Me4 Se2 )] (7) and [(η(6) -p-cymene)Ru(η(4) -C6 H4 SeO)] (8), were determined. The structures confirm the identity of the target compounds and ascertain the coordination mode of these unprecedented ruthenium π complexes of selenoquinones. Furthermore, these new compounds display relevant cytotoxic properties towards human ovarian cancer cells.

Trinuclear Half‐Sandwich RuII, RhIII and IrIII Polyester Organometallic Complexes: Synthesis and in vitro Evaluation as Antitumor Agents

“…The methyl protons of the pentamethylcyclopentadienyl ligands of the rhodium ( 5 , 8 , 11 and 14 ) and iridium ( 6 , 9 , 12 and 15 ) complexes are observed as singlets in the range δ = 1.31–1.60 ppm in the 1 H NMR spectra, similarly to those observed in related structures 18–20. For the mono‐ and trimeric Ru II complexes ( 7 , 10 , 13 and 16 ), the p ‐cymene ligand displays a characteristic pattern as observed in the neutral and cationic complexes previously reported 17,19,21–24. The signal for the methyl protons of the isopropyl group is observed as a doublet in the N , N ‐cationic complexes ( 7 and 13 ) and appear as two doublets in the N , O ‐neutral complexes ( 8 and 14 ), at around δ = 1.08–1.15 ppm.…”

Synthesis and Characterization of Ruthenium-Paraphenylene-Cyclopentadienyl Full-Sandwich Complexes: Cytotoxic Activity against A549 Lung Cancer Cell Line and DNA Binding Properties

“…Similarly, the complex (5) was synthesized. However, the synthesis of the 1:2, L: ({RuCp}, complexes (4) and (7) were achieved through successive in situ reactions. Initially, the 1:1 complex was formed, as described in the cases of ( 3) and ( 6), and without isolating them, additional amounts of [(η 5 -C 5 H 5 )Ru(CH 3 CN) 3 ](PF 6 ) were added.…”

“…Moreover, the high stability of these complexes in aqueous media, attributed to the absence of any potential good leaving group, suggests their capability to interact with biomolecules in a non-coordinative manner, exhibiting promising cytotoxic potential, as evidenced by several reports, reviewed below: Full-sandwich ruthenium complexes containing η 6 -coordinated p-cymene and mono-and di-selenoquinones, have been synthesized and characterized. The complexes display moderate cytotoxicity against A2780 and A278R cancer cell lines, depending on their structure with IC 50 in the range of 19 to 240 µM [7]. The cytotoxic activity of the complex [(η 5 -Cp*)Ru(η 6 -C 6 H 5 CO 2 H)]PF 6 , along with its various esters and amides, was assessed in vitro against the MCF7, MDA-MD-231, and MM96L cancer cell lines.…”

Optically active Pt-terpyridyl coordination assemblies derived from planar chiral metallothioligands

“…[22,25,26] Moreover, the first molecular structures of a diselenoquinone πcomplex stabilized by Cp*Ir and (p-cymene)-Ru moeities were confirmed by a single-crystal X-ray diffraction study. [27,28] In this work we report stable chiral metallothioligands comprising a CpRu moiety and a πbonded arene containing a stereogenic benzylic alcohol and a sulfur donor atom available for coordination purposes. These metallothioligands display planar and central chirality (vide infra).…”