Ruthenium Ion Research Articles

Molecular Self-Assembly of an Unusual Dinuclear Ruthenium(III) Complex Based on the Nucleobase Guanine

The study of crystal structures based on complexes containing purine nucleobases is a significant research subject, mainly regarding the diagnosis and treatment of some diseases and the investigation of genetic mutations and biochemical structures in life sciences. We have obtained and characterized a new dinuclear ruthenium(III) complex based on guanine with the formula [{Ru(µ-Cl)(µ-gua)}2Cl4]·2H2O (1) (gua = guanine). 1 was characterized by means of Fourier transform infrared spectroscopy (FT–IR), scanning electron microscopy and energy dispersive X-ray analysis (SEM–EDX), single-crystal X-ray diffraction (XRD), Hirshfeld surface analysis and cyclic voltammetry (CV). The study of its electrochemical properties allowed us to investigate the presence of guanine molecules when linked to the ruthenium(III) ion in 1. The well-resolved voltammetric response together with the reliability and stability achieved through 1 could provide a step forward to developing new ruthenium-based platforms, devices and modified electrodes adequate to study this purine nucleobase.

Synthesis and Photocatalytic Activity of Ruthenium-Titania for Enhanced Decolorization of Malachite Green under Visible Light Illumination

The photodecolorization of malachite green (MG) dye was effectively done using Ruthenium-doped TiO2 photocatalysts under visible light illumination. X-ray diffraction analysis revealed that anatase and rutile peaks were both found in undoped TiO2 while only anatase peaks were present in Ru-doped TiO2 systems which were calcined at 500°C. The 0.008 Ru-TiO2 photocatalysts calcined at 300°C showed broader peaks compared to those calcined at 500°C. Further increase of calcination temperature to 700°C promotes the transformation of anatase to rutile peaks. The photocatalytic activity of TiO2 was found to increase with the addition of Ruthenium ions, from 20% for undoped TiO2 to 87% for 0.80 Ru-doped TiO2. The maximum photocatalytic removal of MG dye was achieved using 1.50 g∙L-1 of catalyst loading for 0.008 Ru-doped TiO2. The TiO2 photocatalysts prepared at a calcination temperature of 500°C showed higher photodecolorization efficiency compared to those calcined at 300°C and 700°C. Kinetic studies revealed that the photodecolorization of MG using Ru-doped TiO2 followed a first order kinetics.

Ruthenium Complex of sp2 Carbon-Conjugated Covalent Organic Frameworks as an Efficient Electrocatalyst for Hydrogen Evolution.

It is still a great challenge to explore hydrogen evolution reaction (HER) electrocatalysts with both lower overpotential and higher stability in acidic electrolytes. In this work, an efficient HER catalyst, Ru@COF-1, is prepared by complexation of triazine-cored sp2 carbon-conjugated covalent organic frameworks (COFs) with ruthenium ion. Ru@COF-1 possesses high crystallinity and porosity, which are beneficial for electrocatalysis. The large specific surface area and regular porous channels of Ru@COF-1 facilitate full contact between reactants and catalytic sites. The nitrogen atoms of triazines are protonated in the acidic media, which greatly improve the conductivity of Ru@COF-1. This synergistic effect makes the overpotential of Ru@COF-1 about 200mV at 10mAcm-2 , which is lower than other reported COFs-based electrocatalysts. Moreover, Ru@COF-1 exhibits exceptionally electrocatalytic durability in the acidic electrolytes. It is particularly stable and remains highly active after 1000 cyclic voltammetry cycles. Density functional theory calculations demonstrate that tetracoordinated Ru-N2 Cl2 moieties are the major contributors to the outstanding HER performance. This work provides a new idea for developing protonated HER electrocatalysts in acidic media.

New organoruthenium(II) complexes containing N, X-donor (X = O, S) heterocyclic chelators: Synthesis, spectral characterization, in vitro cytotoxicity and apoptosis investigation

Four Schiff base ligands namely ((1E)-1-(1-(6-chloro-2-oxo-2H-chromen-3-yl) ethylidene)semicarbazide) (HL1), ((1E)-1-(1-(6-chloro-2-oxo-2H-chromen-3-yl)ethylidene thiosemicarbazide) (HL2), ((1E)-1-(1-(7-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene) semicarbazide) (HL3) and ((1E)-1-(1-(7-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene) thiosemicarbazide) (HL4) have been prepared, and the direct reaction of these ligands with [RuCl2(η6-p-cymene)]2 yielded the new cationic ruthenium(II) arene complexes (C I - C IV). The compounds were characterized using various spectroscopic methods. Spectroscopic analysis revealed that the ligands coordinated to ruthenium ion in a neutral bidentate fashion via N & S/O atoms. The in vitro anticancer activity of the ligands and complexes have been screened using MTT assay with two cancer cell lines, namely MCF-7 (human breast cancer cells) and A549 (human lung carcinoma). Interestingly, the cytotoxic nature of the complexes is much more potent than the standard drug cisplatin and their parent ligands with low IC50 values. The non-toxic nature of the compounds has been confirmed with human umbilical vein endothelial cells HUVEC cells. The morphological changes of the MCF-7 and A549 cells with the complexes C I- C IV have been studied by AO-EB (Acridine Orange-Ethidium Bromide) and Hoechst staining methods, and these results revealed that the complexes induced cell death only through apoptosis. The cytotoxic nature of the compounds was found to be C IV > C III > C II > C I > cisplatin > ligands. Complex C IV showed better activity due to the electron-donating hydroxyl group present in the 7th position of the coumarin ring. These results highlighted the strong possibility to develop highly active ruthenium arene complexes as anticancer agents.

Ru-Doped NiFe Layered Double Hydroxide as a Highly Active Electrocatalyst for Oxygen Evolution Reaction

Improving the intrinsic catalytic activity of NiFe layered double hydroxide (LDH), which is a benchmark electrocatalyst for oxygen evolution reaction (OER), is a significant challenge. In the present study, we doped ruthenium ions into NiFe LDH (Ru-NiFe LDH) to accelerate the OER kinetics. Electrochemical measurements of NiFe LDH and Ru-NiFe LDH at similar mass loadings showed that Ru-NiFe LDH demonstrated a higher OER activity than that of NiFe LDH. Ru-NiFe LDH only requires an overpotential of 246 mV at 10 mA cm−2 in alkaline media. This attributes to ruthenium doping primarily, which can promote the catalytic activity of Fe sites and boost the electronic interaction among the Ni, Fe, and Ru metals according to the theoretical calculations. Ru-NiFe LDH is stable during OER stability measurements, which was confirmed by structure and elemental analysis. These findings will provide a useful approach for promoting the intrinsic activity of multi-metallic (oxy) hydroxide electrocatalysts toward the OER.

Triggering anionic redox activity in Fe/Mn-based layered oxide for high-performance sodium-ion batteries

Among various sodium-ion cathode materials, Fe/Mn-based layered oxides stand out due to cost-effectiveness and relatively high theoretical specific capacity. However, further enhancement in capacity and improvement in cyclability are still needed to meet the requirements for practical applications in sodium-ion batteries. Herein, we report that ruthenium-doped Na0.67Fe0.5Mn0.5O2 can not only achieve high reversible capacity but also deliver superior cycling stability. Owing to the substitution of 4d ruthenium heteroatoms, the cathode exhibits promising electrochemical performance with a higher reversible specific capacity of 170 mA h g−1 at 0.2C between 2 and 4 V as well as a stable cycling performance with 82.2% capacity retention at 2C after 100 cycles compared to its pristine counterpart. Advanced structural characterization techniques combined with theoretical calculations unveil that the presence of ruthenium ions can trigger anionic redox activity, thus leading to harvesting of extra capacity. Moreover, ruthenium ions can also play an important role in stabilizing and improving the structural framework, resulting in prominent cyclability and excellent rate performance. Overall, the present work demonstrates that anionic redox activity could be triggered by integration of trace 4d element in Fe/Mn-based layered oxides and represents an effective strategy to develop high-performance sodium cathodes.

Investigation of CO and OH adsorption and oxidation in the presence of cocatalytic ruthenium ions on the Pt(111) surface

We present Density Functional Theory (DFT) calculations for COads adsorption and COads + OHads ➔ CO2 + Hads reactions on a Pt(111) slab with, and without, adsorbed RuCl5. CO stretching frequencies and bond distances between CO and PtC were calculated. The derived activation energies and reaction energies provide strong evidence that the OHads on the Pt(111) surface oxidatively remove COads in a kinetically more facile manner in the presence of co-adsorbed RuCl5. Methanol catalytic activation by cocatalytic RuCl5 ions offers a promising and convenient route to implementing a methanol-feed with trace levels of Ru ions under fuel cell operating conditions.

The reaction mechanism of acetylene hydrochlorination on defective carbon supported ruthenium catalysts identified by DFT calculations and experimental approaches

The electron density of ruthenium ions in RuCl3/AC-D catalyst increases, which reduces the energy barrier of the main reaction and inhibits the side reactions.

Structural, spectral, and photoreactivity properties of mono and polymetallated-2,2′-bipyridine ruthenium(II) complexes

Polymetallated-2,2′-bipyridine–ruthenium(II) complexes exhibit photosensitization properties and can enhance optically induced NO release, thus modeling multi-site catalysts. Two novel ruthenium-nitrosyl complexes [RuCl2LA(NO)]PF6 (herein called RuLANO, LA = 2,6-bis[(aniline)methyl]-pyridine) and [RuCl2(NO)({Ru(bpy)2}2-μ-LB)](PF6)5 (herein called Ru3LBNO, LB = 2,6-bis[(1,10-phenantroline-5-amine)methyl]-pyridine) were prepared and structurally characterized (1H-, 13C-, DEPT-135 NMR, FTIR, UV–Vis, elemental analysis, ESI-HRMS, and single crystal x-ray diffraction). RuLANO showed a trans configuration of the chloride ligands, and photo-release of chloride is the major process upon irradiation of RuLANO at 377 nm, along with some NO dissociation to a small extent. In contrast, the trinuclear ruthenium complex Ru3LBNO was found to be photo-inactive with irradiation between 377 and 447 nm (region of absorption of the {Ru(bpy)2(phen)}2+ chromophore) in the same conditions of RuLANO. This result agrees with the strong stabilization of Rucentral dxy, dxz, and dyz orbitals as shown by calculations using density functional theory (DFT), as well as with the electrochemical response, which supports that there is no major electronic communication between the central and the peripherals ruthenium ions in the trinuclear complex.

A study on the structure of Naomaohu coal and its suitability for direct coal liquefaction

Direct coal liquefaction (DCL) is not only for fuel but also for chemicals, which shows high efficiencies in atom utilization and energy. The study on coal structure is important to select coal for direct liquefaction. Naomaohu coal is a kind of subbituminous coal and a typical coal for direct liquefaction. In this work, the structure of Naomaohu coal was investigated via alkali‑oxygen oxidation, ruthenium ion catalyzed oxidation and physical analyses and a representative structural model with a model size of 128,755 amu was constructed. The structural characteristics show that the ratio of single-, double-, triple-, and quadruple-aromatic rings is 149:164:102:63. The triple- and quadruple-rings aromatic structures are mainly connected by CC bonds of 2–4 carbon atoms. The single- or double-ring is connected on the triple- and quadruple-rings aromatic structures through ether or ester bonds, which can be broken easily under mild conditions. Long alkyl side chains with carbon atoms from 13 to 25 accounting for 0.91 wt%. The high H/C, high oxygen content (mainly weak bonds such as ether and ester bonds between aromatic clusters), abundant single-, double-, triple, and quadruple-aromatic rings, and alkyl bridge bonds of 2–4 carbon atoms are beneficial to the mild liquefaction of Naomaohu coal

Stimulation of Sulfonamides Antibacterial Drugs Activity as a Result of Complexation with Ru(III): Physicochemical and Biological Study.

Antibiotic resistance is a global problem, and one promising solution to overcome this issue is using metallodrugs, which are drugs containing metal ions and ligands. These complexes are superior to free ligands in various characteristics including anticancer properties and mechanism of action. The pharmacological potential of metallodrugs can be modulated by the appropriate selection of ligands and metal ions. A good example of proper coordination is the combination of sulfonamides (sulfamerazine, sulfathiazole) with a ruthenium(III) ion. This work aimed to confirm that the activity of sulfonamides antibacterial drugs is initiated and/or stimulated by their coordination to an Ru(III) ion. The study determined the structure, electrochemical profile, CT-DNA affinity, and antimicrobial as well as anticancer properties of the synthesized complexes. The results proved that Ru(III) complexes exhibited better biological properties than the free ligands.

Assessment of antiproliferative activity of new half‐sandwich arene Ru (II) furylbenzhydrazone complexes

AbstractThe study attempts in finding an effective anticancer activity of six new arene ruthenium (II) complexes possessing the composition of [(η6‐arene)Ru(L)Cl] (arene = benzene (1–3) /p‐cymene (4–6); L = 2‐furyl methyl benzhydrazones). Elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), UV–vis, nuclear magnetic resonance (NMR), and high resolution mass spectrometry (HR‐MS) techniques were utilized to study the synthesized complexes. The single crystal X‐ray crystallography validated the bidentate mode of coordination of the benzhydrazone ligand and pseudo‐octahedral geometry around ruthenium ion. MTT assay has been performed to assess the in vitro growth of cancer cell inhibition ability of all the complexes against MCF‐7(breast carcinoma), HuH‐7 (hepatocellular carcinoma), and HeLa (cervical cancer), along with non‐cancerous L132 (human lung epithelium) cell lines. It has been found that all the six complexes exhibit good to excellent cytotoxicity toward the cancer cell lines tested with low IC50 values compared to cisplatin. Among the synthesized complexes, complex 6 shows potential cytotoxicity against all the cancer cell lines. The observed higher cytotoxicity of the complex 6 may be due to the electron donating methoxy group of the ligand and hydrophobic character of arene moiety. Eventually, the staining techniques such as AO‐EB, HOECHST 33342, RH‐123, and reactive oxygen species (ROS) establish that all the complexes bring about cell death via apoptosis. The present research results emphasize the more possibility to promote potential arene ruthenium anticancer agents.

Metal-nitrogen intimacy of the nitrogen-doped ruthenium oxide for facilitating electrochemical hydrogen production

In order to realize electrochemically efficient hydrogen production, various endeavors have been devoted to developing hydrogen evolution reaction (HER) electrocatalysts having zero hydrogen binding energy (ΔGH* = 0) for balancing between adsorption and desorption. This work demonstrated that nitrogen doping improved the HER activity of ruthenium oxide by letting its ΔGH* approach zero or facilitating hydrogen desorption process. A highly nitrogen-doped ruthenium oxide catalyst guaranteeing the ruthenium-nitrogen intimacy was prepared by employing a polymer whose nitrogen-containing moiety (pyrrolidone) was strongly coordinated to ruthenium ion in the precursor solution prior to calcination. The less electronegative nature of nitrogen (when compared with oxygen) decreased the free energy uphill required for desorption of hydrogen intermediate species sitting on the nitrogen (H-*N to 1/2 H2 + *N) to make the desorption process more favored. Also, the nitrogen dopant facilitated OH- desorption from its neighboring ruthenium site (HO-*Ru + e- to HO- + *Ru) since the less electronegative nitrogen withdrew less electrons from the ruthenium site. The ruthenium-nitrogen intimacy of the catalyst more than doubled the electrocatalytic HER current from 33 mA cm−2 for an undoped RuO2 to 79 mA cm−2 for the nitrogen-doped RuO2 at −50 mVRHE.

Ruthenium Complexes with 2-Pyridin-2-yl-1H-benzimidazole as Potential Antimicrobial Agents: Correlation between Chemical Properties and Anti-Biofilm Effects.

Antimicrobial resistance is a growing public health concern that requires urgent action. Biofilm-associated resistance to antimicrobials begins at the attachment phase and increases as the biofilms maturate. Hence, interrupting the initial binding process of bacteria to surfaces is essential to effectively prevent biofilm-associated problems. Herein, we have evaluated the antibacterial and anti-biofilm activities of three ruthenium complexes in different oxidation states with 2-pyridin-2-yl-1H-benzimidazole (L1 = 2,2′-PyBIm): [(η6-p-cymene)RuIIClL1]PF6 (Ru(II) complex), mer-[RuIIICl3(CH3CN)L1]·L1·3H2O (Ru(III) complex), (H2L1)2[RuIIICl4(CH3CN)2]2[RuIVCl4(CH3CN)2]·2Cl·6H2O (Ru(III/IV) complex). The biological activity of the compounds was screened against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa strains. The results indicated that the anti-biofilm activity of the Ru complexes at concentration of 1 mM was better than that of the ligand alone against the P. aeruginosa PAO1. It means that ligand, in combination with ruthenium ion, shows a synergistic effect. The effect of the Ru complexes on cell surface properties was determined by the contact angle and zeta potential values. The electric and physical properties of the microbial surface are useful tools for the examined aggregation phenomenon and disruption of the adhesion. Considering that intermolecular interactions are important and largely define the functions of compounds, we examined interactions in the crystals of the Ru complexes using the Hirshfeld surface analysis.

Synthesis, characterization, and antimicrobial activity investigations of ruthenium (II)–bipyridine complexes of ciprofloxacin derivatives

AbstractA series of ruthenium (II) complexes derived from the reaction between cis‐bis (2,2′‐bipyridine) dichloro ruthenium (II) dihydrate and enaminone derivatives of ciprofloxacin were synthesized and fully characterized using elemental analysis, cyclic voltammetry and different spectroscopic techniques (Uv–vis, FTIR, NMR, mass spectroscopy, and X‐ray photoelectron spectrometry (XPS)). The isolated compounds were tested for their antibacterial and antifungal activities against gram‐negative and gram‐positive bacteria. The FTIR data revealed that ciprofloxacin derivatives act as bidentate ligands through the pyridone carbonyl and the carboxylate oxygen atom. The UV–visible data showed that the charge transfer CT band is blue shifted upon the coordination of the ciprofloxacin derivatives compared to the CT band of the parent complex. The XPS results revealed the characteristic peaks of Ru3p3/2and Ru3p1/2as well as Ru3d5/2and Ru3d3/2, which confirmed the assembly of the ruthenium (II) ciprofloxacin derivative complexes. Cyclic voltammetry data showed that the ciprofloxacin enaminone derivatives have a similar reduction potential for the Ru (II)/Ru (III) redox couple, and it revealed that the coordination of the ruthenium (II) ion altered the redox property of the ligands and enhanced their electron transfer rate. The electrochemical and the UV–visible results suggest that the ciprofloxacin derivative ligands are‐acceptor ligands. Further, the complexes showed higher antibacterial activities than the parent ciprofloxacin antibiotic and did not show antifungal activities among the tested fungi strains.

Syntheses and characterization of RuxV1-xO2 (0≤x≤0.05)/graphene nanocomposites for flexible supercapacitors and energy storage devices

Herein, we report the syntheses of RuxV1-xO2/graphene hybrid nanocomposites using a one-step laser scribe approach for supercapacitors and energy storage devices. A series of RuxV1-xO2 (0 ≤ x ≤ 0.05) nanowires decorated graphene were prepared. The effect of ruthenium ions (Ru) on the structure, morphology, elemental composition and oxidation state of the RuxV1-xO2/graphene hybrid nanocomposites was explored using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The electrochemical properties were emphasized using the electrochemical impedance spectroscopy (EIS), cyclic Voltammetry and galvanostatic charge/discharge measurements. The RuxV1-xO2/graphene hybrid nanocomposites showed a specific capacitance of 1210 F g−1 at a Ru-concentration of 5 mol%. The Ru0·05V0·95O2/LSG hybrid electrode exhibits excellent capacitance retention up to a current density of 350 A g−1, suggesting a good application prospect for energy storage devices.

Synthesis and Characterization of Metallo-Supramolecular Polymers Based on Benzodipyrrolidone.

A simple route to the preparation of benzodipyrrolidone (BDP) based monomeric building blocks containing 2,2′:6′,2″-terpyridines is reported from a common precursor 4′-(4-pinacolatoboronphenyl)-2,2′:6′,2″-terpyridine via Suzuki coupling reaction. Self-assembly polymerization with ruthenium (II) ions under mild conditions yielded a series of novel metallo-supramolecular polymers with weak donor-acceptor (D-A) structures based on benzodipyrrolidone. The structure of the bridge connected BDP with terpyridine have a significant impact on the wavelength and intensity of the intramolecular charge transfer (ICT) absorption peak. The resulting metallo-polymers exhibited strong double absorption bands around 315 nm and 510 nm involved in π-π* transitions and ICT or metal to ligand charge transfer (MLCT) absorption bands. The forming of D-A structure and coordination with ruthenium (II) ions is favorable to narrow the energy gap and the energy gaps of the resulting metallo-supramolecular polymers are 2.01 and 1.62 eV, respectively.

Potential Therapeutic Effects of New Ruthenium (III) Complex with Quercetin: Characterization, Structure, Gene Regulation, and Antitumor and Anti-Inflammatory Studies (RuIII/Q Novel Complex Is a Potent Immunoprotective Agent)

The aim of this study was to evaluate the antioxidant and anti-inflammatory effects of the new [Ru(Q)(Cl)2(H2O)2] complex (RuIII/Q). A new vital complex containing quercetin flavonoid compound (Q) with ruthenium (III) ions was synthesized. The molar conductivity of the RuIII/Q complex was measured in dimethylsulfoxide (DMSO) with value 12 (Ω−1 mol−1 cm−1, indicating their non-electrolytic nature. Infrared (FTIR) spectroscopic investigation of the RuIII/Q complex indicated that Q is coordinated as a bidentate with Ru metal ions through the oxygen of carbonyl C(4)=O group and oxygen of phenolic C(3)−O group based on the wavenumber shifts at 1654 and 1335 cm−1 respectively. The electronic (UV−Vis) spectra and the magnetic susceptibility value (1.85 B.M.) revealed that the Ru(III) complex has an octahedral geometry. The average diameter of the RuIII/Q nanoparticles was approximately 7–15 nm according to the transmission electron microscopy. The thermogravimetric study (TG/DTG) indicates that the RuIII/Q compound is quite stable until 300 °C. To assess biological activity, 60 male rats were allocated to six groups, namely control, DG (D-galactose), Q, RuIII/Q, DG plus Q, and DG plus RuIII/Q. Antioxidant enzymes (SOD, CAT, GPx, and GRx), markers of lipid peroxidation (such as MDA), expression of genes (namely Nrf2, Cu-ZnSOD, CAT, GPx, cyto c, P53, Bax, BCl2, caspase-3, and caspase-9 in testicular tissue), glutamate, 4-hydroxynonenal (HNE), GSH, HCY, amyloid beta, and GABA levels were evaluated in brain tissues. Cytokines, such as IL-6 and TNF-α, histological and ultrastructural studies were estimated in both the brain and testicular tissues, while the comet assay was performed in the brain tissue. RuIII/Q administration either alone or combined with DG reduced oxidative injury to normal levels and decreased apoptotic activities. Thus, RuIII/Q inhibited injury in both the testis and brain and reduced oxidative stress in male rats. The (RuIII/Q) complex has a potent ameliorative effect against aging neurotoxicity, reproductive toxicity, and antihepatic cancer activity induced by D-galactose (DG).

First 97Ru complex with pyridine-2,6-dicarboxamide conjugate for potential use as radiopharmaceutical

A new peptidomimetic conjugate of natural methionine and pyridine-2,6-dicarboxylate was synthesized and evaluated as a potential ligand for 97Ru radiopharmaceuticals. The distribution of this radiopharmaceutical in mice was investigated. A fundamental difference was found in the distribution and excretion of ruthenium complex and free ruthenium ion in the body, which suggests a difference in their transport pathways due to the stability of the complex in the body.

Preparation of a dicationic, p-cymene ruthenium(II) dimer, [(p-cymene)Ru(µ-Cl)(P{OCH2}3CEt)]2 2+: structure, characterization and reactivity

Reaction of (p-cymene)RuCl2(P{OCH2}3CEt) (P{OCH2}3CEt = 4-ethyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane) with silver tetrakis[(3,5-trifluoromethyl)phenyl]borate (Ag[BArF′]) in the presence of acetonitrile produces the monomeric, cationic, acetonitrile ruthenium(II) compound, [(p-cymene)RuCl(P{OCH2}3CEt)(NCMe)][BArF′] (1), in near quantitative yields (97%). Chloroform solutions of 1 cause precipitation of the binuclear, dicationic ruthenium(II) dimer complex, [(p-cymene)Ru(µ-Cl(P{OCH2}3CEt)]2[BArF′]2 (2), with bridging chloride ligands (73%). Complex 2 can be readily converted back to 1 by treatment with acetonitrile. Complexes 1 and 2 were characterized by 1H, 13C{1H}, 31P{1H}, 19F{1H} nuclear magnetic resonance spectroscopy and infrared spectroscopy. Complex 2 was also characterized by single crystal X-ray crystallography, which revealed a rhomboid Ru2Cl2 core. The two ruthenium ions in 2 are displaced at 3.668 Å, which precludes Ru–Ru bonding. To our knowledge, this is the first cymene ruthenium(II) dimeric complex with bridging halide ligands supported by a monodentate phosphite ligand.