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Two ruthenium(II) polypyridyl complexes were prepared with the {Ru(phen)2}2+ moiety and a third sterically non-hindering bidentate ligand, namely 2,2′-dipyridylamine (dpa) and N-benzyl-2,2′-dipyridylamine (Bndpa). Hence, complexes [Ru(phen)2(dpa)](PF6)2 (1) and [Ru(phen)2(Bndpa)](PF6)2 (2) were characterized and their photochemical behaviour in solution (acetonitrile and water) was subsequently investigated. Compounds 1 and 2, which do not exhibit notably distorted octahedral coordination environments, contrarily to the homoleptic “parent” compound [Ru(phen)3](PF6)2, experience two-step photoejection of the dpa and Bndpa ligand upon irradiation (1050–430 nm) for several hours. DNA-binding studies revealed that compounds 1 and 2 affect the biomolecule differently upon irradiation; while 2 solely modifies its electrophoretic mobility, complex 1 is also capable of cleaving it. In vitro cytotoxicity studies with two cancer-cell lines, namely A549 (lung adenocarcinoma) and A375 (melanoma), showed that both 1 and 2 are not toxic in the dark, while only 1 is significantly cytotoxic if irradiated, 2 remaining non-toxic under these conditions. Graphical abstract Light irradiation of the complex cation [Ru(phen)2(dpa)]2+ leads to the generation of transient Ru species that is present in the solution medium for several hours, and that is significantly cytotoxic, ultimately producing non-toxic free dpa and [Ru(phen)(OH2)2]2+.

Four divinylphenylene-bridged diruthenium complexes [{Ru(CO)(P i Pr3)2(L-κ 2 [N,O] – )}2(μ-CH=CH-C6H4-CH=CH-1,4)] (2a–2d) with N,O-chelating 2-hydroxypyridine and 2-hydroxy- or 8-hydroxyquinoline ligands are presented. They were studied by NMR spectroscopy, electrochemical methods and, in their neutral and oxidized states, by IR, UV/Vis/NIR and, if applicable, by EPR spectroscopy. The experimental studies are complimented by (TD-)DFT calculations. Our results indicate that the pyridine-olate complexes 2a,b exist as three isomers with a ratio of about 78:20:2 that differ with respect to the orientation of the N and O donors relative to the CO and alkenyl ligands in the equatorial coordination plane. Only the isomer with both imine N donors trans to the alkenyl ligand is observed for complexes 2c,d with quinolinato ligands. All complexes undergo two consecutive, chemically and electrochemically reversible one-electron oxidations at low potentials. Our results indicate strong contributions of the divinylphenylene bridge to the redox processes and an even delocalization of the electron hole and the unpaired spin density over the entire π-conjugated divinylphenylene diruthenium backbone with only minor involvement of the peripherally attached κ 2 [N,O] – donor ligands.

Detecting cancer at the early stage of the disease is crucial to keep the best chance for successful treatment. The recent development of genomic screening, a methodology that is addressed to asymptomatic patients presumably at risk of carcinogenesis, has stimulated the quest for new tools able to signal the level of risk. Carcinogenesis has been associated to chronic oxidative stress exceeding the antioxidant defenses and leading to critical genome alteration levels. The telomeric regions are presumably the most exposed to oxidative stress due to their high concentration of guanine (i.e., the easiest oxidizable nucleic base). Accumulation of 8-oxoguanine in telomeres, thus oxidative lesions, was reportedly associated with telomeric crisis and carcinogenesis. In this study, we report on the capacity of Ru(II) polyazaaromatic complexes to photoprobe 8-oxoguanine into the human telomeric sequence with the view of developing new tools for cancer risk screening.

Indane and isoindoline are attractive bicyclic systems in biologically active compounds but are rarely reported in DNA-encoded libraries. In this paper, we reported an efficient and versatile approach for assembling indane and isoindoline scaffolds via a ruthenium-catalyzed [2 + 2 + 2] cyclotrimerization reaction. This method exhibits a broad substrate scope and has been successfully applied to construct a 53K-membered DNA-encoded library (DEL). In order to test its application, we carried out a preliminary selection of this DEL against Aurora A protein and identified a hit compound with 9.3 μM inhibition activity.

Control of polymer molecular weight is critical for tailoring structure-function properties; however, traditional molecular weight characterization techniques have limited ability to determine the molecular weight of polymers in real time without sample removal from the reaction mixture, with spatial resolution, and of insoluble polymers. In this work, a fluorescence lifetime imaging microscopy (FLIM) method was developed that overcomes these limitations. The method is demonstrated with polynorbornene and polydicyclopentadiene, polymers derived from ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The polymer

The synthesis and biological assessment of neutral or cationic platinum group metal-based anticancer complexes have been extremely studied, whereas there are few reports on the corresponding zwitterionic complexes. Herein, the synthesis, characterization, and bioactivity of zwitterionic half-sandwich phosphine-imine iridium(III), rhodium(III), and ruthenium(II) complexes were presented. The sulfonated phosphine-imine ligand and a group of zwitterionic half-sandwich

Amide bond reduction is a versatile transformation offering access to various alcohols and amines which could be used as valuable precursors in the chemical and pharmaceutical industries, e.g. for manufacturing plastics, textiles, dyes, agrochemicals, etc. Over the last two decades, catalytic amide hydrogenation employing homogenous catalysis has gained more attention due to the atom efficiency and low environmental impact of this transformation. Owing to the inherent strength of amide bonds, amide hydrogenation procedures often involve high temperatures and pressures, which is why efforts are being channeled to finding protocols with lower energy input. Here, we report a mild amide hydrogenation method involving commercially available precursors Ru(acac)3 and 1,2-bis(di-tert-butylphosphinomethyl)benzene (L4), which under basic conditions, at 80 ˚C and under 30 bar of H2 can selectively hydrogenate a series of 2˚-benzamides to anilines and alcohols with yields ranging from 36–98% and 29–92%, respectively. Additionally, 1˚- and 3˚-amides proved to be appropriate substrates, however, low to moderate yields were obtained. The catalyst is believed to operate via an inner-sphere mechanism with a hemiaminal being the likely intermediate during the hydrogenation process.

Nanoscale patterning of inorganics is crucial for the fabrication of advanced electronic, photonic, and energy devices. The emerging sequential infiltration synthesis (SIS) method fabricates nanofeatures by block-selective vapor-phase growth in block copolymer templates with tunable patterns. Yet, SIS has been demonstrated mainly for Al2O3 and a few other metal oxides, while deriving metal nanostructures from a single SIS process is a challenge. Here, we present SIS of the Ru metal in polystyrene-block-polymethyl methacrylate (PS-b-PMMA) templates without any pretreatment, using alternating infiltration of RuO4 and H-2. RuO4 interacts selectively and strongly with the aromatic C=C and C-H groups in PS, leaving the PMMA domains inert. Density functional theory calculations corroborate that the PS-RuO4 interaction is energetically favorable, with a calculated interaction energy of -1.65 eV, whereas for PMMA-RuO4, the calculated energy of -0.05 eV indicates an unfavorable interaction. Morphological analysis on the di-BCP after the RuO4-H-2 process indicates an increase in contrast as a function of SIS cycles and templated Ru incorporation. The crystalline nature of the Ru deposits is confirmed using grazing incidence wide-angle X-ray scattering. Plasma-aided removal of the organic components yields Ru nanolines with lateral dimensions of ca 20 nm. We further highlight the broad potential of RuO4 as a reactant for SIS by generating RuO2 nanopatterns via alternating RuO4 and methanol infiltration.

Incorporating water-insoluble nitric oxide (NO)-releasing molecules into biocompatible vesicles may allow for the tunable control of NO release on a specific target site. In vesicles, membrane fluidity plays an important role and influences the final therapeutic efficiency of drugs loaded into the vesicles. Hence, we aimed to investigate the effect of lipid fluidity on the NO release behavior of the photo-controllable ruthenium nitrosyl (Ru-NO) complex. In this regard, a new photoactive ruthenium nitrosyl complex (

Carbon monoxide (CO) has been regarded as a "silent killer" for its toxicity toward biological systems. However, a low concentration of endogenously produced CO has shown a number of therapeutic benefits such as anti-inflammatory, anti-proliferative, anti-apoptosis, and cytoprotective activities. Carbon monoxide-releasing molecules (CORMs) have been developed as alternatives to direct CO inhalation, which requires a specialized setting for strict dose control. CORMs are efficient CO donors, with central transition metals (such as ruthenium, iron, cobalt, and manganese) surrounded by CO as a ligand. CORMs can stably store and subsequently release their CO payload in the presence of certain triggers including solvent, light, temperature, and ligand substitution. However, CORMs require appropriate delivery strategies to improve short CO release half-life and target specificity. Herein, we highlighted the therapeutic potential of inhalation and CORMs-delivered CO. The applications of conjugate and nanocarrier systems for controlling CO release and improving therapeutic efficacy of CORMs are also described in detail. The review concludes with some of the hurdles that limit clinical translation of CORMs. Keeping in mind the tremendous potential and growing interest in CORMs, this review would be helpful for designing controlled CO release systems for clinical applications.

International audience; The highly selective ruthenium-catalyzed ortho-C-H bond arylations have met a level of maturity that makes them an attractive tool to achieve unique organic transformations. By means of the manifold mechanisms operating in the presence of different arylating agents and reaction conditions, these methodologies have succeeded in reducing the wastes/steps toward the desired molecules as well as enlarging the chemical space by affording molecules impossible to obtain otherwise. The key achievements in this area are discussed in this article.

The curative effect of sorafenib in hepatocellular carcinoma (HCC) is limited and sorafenib resistance remains a major obstacle for HCC. To overcome this obstacle, a new photoactive sorafenib-Ru(II) complex Ru-Sora has been designed. Upon irradiation (λ = 465 nm), Ru-Sora rapidly releases sorafenib and generates reactive oxygen species, which can oxidize intracellular substances such as GSH. Cellular experiments show that irradiated Ru-Sora is highly cytotoxic toward Hep-G2 cells, including sorafenib-resistant Hep-G2-SR cells. Compared to sorafenib, Ru-Sora has a significant photoactivated chemotherapeutic effect against Hep-G2-SR cancer cells and 3D Hep-G2 multicellular tumor spheroids. Furthermore, Ru-Sora inducing apoptosis and ferroptosis is proved by GSH depletion, GPX4 downregulation, and lipid peroxide accumulation. Metabolomics results suggest that Ru-Sora exerts photocytotoxicity by disrupting the purine metabolism, which is expected to inhibit tumor development. This study provides a promising strategy for enhancing chemotherapy and combating drug-resistant HCC disease.

The synthesis and photophysical characterization of two osmium(II) polypyridyl complexes, [Os(TAP)

Abstract: Human parasitic infections cause a combined global mortality rate of over one million people per annum and represent some of the most challenging diseases for medical intervention. Current chemotherapeutic strategies often require prolonged treatment, coupled with subsequent drug-induced cytotoxic morbidity to the host, while resistance generation is also a major concern. Metals have been used extensively throughout the history of medicine, with more recent applications as anticancer and antimicrobial agents. Ruthenium metallotherapeutic antiparasitic agents are highly effective at targeting a range of key parasites, including the causative agents of malaria, trypanosomiasis, leishmaniasis, amoebiasis, toxoplasmosis and other orphan diseases, while demonstrating lower cytotoxicity profiles than current treatment strategies. Generally, such compounds also demonstrate activity against multiple cellular target sites within parasites, including inhibition of enzyme function, cell membrane perturbation, and alterations to metabolic pathways, therefore reducing the opportunity for resistance generation. This review provides a comprehensive and subjective analysis of the rapidly developing area of ruthenium metal- based antiparasitic chemotherapeutics, in the context of rational drug design and potential clinical approaches to combatting human parasitic infections.

Abstract: Metal based therapy is no new in biomedical research. In early days, the biggest limitation was the inequality among therapeutical and toxicological dosages. Ever since, Barnett Rosenberg discovered cisplatin, a new era has begun to treat cancer with metal complexes. Platinum complexes such as oxaliplatin, cisplatin, and carboplatin, seem to be the foundation of metal/s-based components to challenge malignancies. With advancement in the biomolemoecular mechanism, researchers have started developing non-classical platinum-based complexes, where a different mechanistic approach of the complexes is observed towards the biomolecular target. Till date, larger numbers of metal/s-based complexes were synthesized by overhauling the present structures chemically by substituting the ligand or preparing the whole novel component with improved cytotoxic and safety profiles. Howsoever, due to elevated accentuation upon the therapeutic importance of metal/s-based components, a couple of those agents are at present in clinical trials and several other are in anticipating regulatory endorsement to enter the trial. This literature highlights the detailed heterometallic multinuclear components, primarily focusing on platinum, ruthenium, gold and remarks on possible stability, synergism, mechanistic studies and structure activity relationships.

The unsustainable antibacterial activity of ruthenium antibacterial agents is an important factor limiting their applications. This present work attempts to prepare ruthenium (Ru) coordination polymer composites with chitosan quaternary ammonium polymers (CQ) and shikimic acid (SA) through the interaction of ionic bonds and covalent bonds by microwave-assisted high-pressure homogenization methods. The prepared CQ@Ru-SA was characterized by size distribution, zeta potential, TEM, UV-vis, FTIR, XPS and XRD analyses. The coordination structure and morphology of Bridge-CQ-NH-Ru-SA were verified. The CQ@Ru-SA was well-dispersed in both the aqueous or anhydrous states. MIC and MBC, time-killing curves, biofilm formation inhibition assay, mature biofilm disruption assay, SEM, Ca

Geometric isomers of mononuclear ruthenium(II) complexes

The quinazolinone template offers an exciting potential for transforming molecules into useful bioactivity. Herein, we report the first regioselective C-5 alkenylation of quinazolinone-coumarin conjugates via ruthenium(II) catalyst using amide as a weak directing group. This methodology permits excellent regioselectivity, extensive substrate tolerance, and mild reaction conditions. In addition, it generates interesting fluorophores that show positive solvatochromism in the range from 404 nm (toluene) to 541 nm (methanol).

There has been emerging interest in the exploitation of the photophysical and photochemical properties of transition metal complexes for diagnostic and therapeutic applications. In this Perspective, we highlight the major recent advances in the development of luminescent and photofunctional transition metal complexes, in particular, those of rhenium(I), ruthenium(II), osmium(II), iridium(III), and platinum(II), as bioimaging reagents and phototherapeutic agents, with a focus on the molecular design strategies that harness and modulate the interesting photophysical and photochemical behavior of the complexes. We also discuss the current challenges and future outlook of transition metal complexes for both fundamental research and clinical applications.

Fischer-Tropsch synthesis was carried out with a ruthenium catalyst by using H2/D2 switching and competitive methods. The results showed that there is an inverse isotope effect during ruthenium-catalyzed Fischer-Tropsch reactions with the hydrocarbon production rate increasing when syngas was switched to D2/CO. When the ruthenium-catalyzed Fischer-Tropsch synthesis was conducted using a mixture of H2/D2/CO (1:1:1) as the syngas, the H/D ratios in hydrocarbons produced by the reaction are less than 1, indicating that the deuterium was enriched in these hydrocarbons. Also, the deuterium enrichment is a function of carbon number with more deuterium enriched in larger hydrocarbons. These results are similar to the results of cobalt and iron catalyzed Fischer-Tropsch reactions we have reported earlier. To explain these results and other experimental facts accumulated over the years about Fischer-Tropsch synthesis, we proposed the alkylidene mechanism for this important reaction, in which MCH is the monomer of this polymerization-like reaction and M=CHR is the growing chain. Based on this mechanism, we developed mathematic equations for each step of propagations to calculate the deuterium enrichment. The theoretic deuterium enrichment results calculated based on the Alkylidene mechanism are very close to the experimental results of deuterium enrichment of ruthenium-catalyzed Fischer-Tropsch reactions.

Cancer targeted nanomaterials-based drug delivery systems have been described as promising. In this work, we employed silk fibroin (SF), ruthenium nanomaterials (RuNMs), heptapeptide (T7), and fingolimod (FTY720) to construct a pH-responsive smart nanomaterials drug delivery system. They were spherical with a mean size of around 120 nm, which may have contributed to the improved penetration and retention of the NMs in tumour areas. T7-FTY720@SF-RuNMs had an encapsulation efficiency (EE) of 72.51 ± 4.02%. When the pH of an environment is acidic, the release of FTY720 from nanocarriers is enhanced. T7-FTY720@SF-RuNMs demonstrated increased cellular uptake selective and anticancer efficacy for hepatocellular cancer in bothiin vitro/iandiin vivo/iexperiments. Additionally, theiin vivo/ibiodistribution investigation showed that T7-FTY720@SF-RuNMs could efficiently aggregate in the tumour location, improving theiriin vivo/ipotential to kill cancer cells. T7-FTY720@SF-RuNMs demonstrated little toxicity to tumour-bearing animals in investigations of histology and immunohistochemistry, showing that the fabricated NMs are biocompatibleiin vivo/i. For the treatment of hepatocellular cancer, the T7-FTY720@SF-RuNMs delivery method offers significant promise.

Construction of the C-C bond has been a challenge for organic chemists because of the reactivity of carbon atoms. The development of nucleophilic carbon was started with the Grignard reagent, enolate, and then ylide, however, the aromatic carbon activation was challenging till the era of organometallic chemistry. The organometallic chemistry was recognized when the Nobel Prize 2010 was given for the C-C bond forming organmetallic reaction; however, the pre functionalization of the C-H bond was an additional step with halogenated reagent, which was the limitation of this reaction. Later, the C-H activation with organometals like Pd, Ru, Cu, Rh, and other transition metal came into existence, where the directing group and metals were found to be sufficient to form the nonreactive C-C bond. In spite of several organometals, Ru acquired a special place due to the reactivity, cost and, stability. Various C-H activation reaction protocols were reported with their high regioselectivity as well as high atom economy. The C-H activation protocol involves the next level of development like SP3, SP2 ortho, meta, and para C-H activation. Here, our aim is to summarize the information regarding Ru and their ortho -regioselective reactions with the help of directing groups. The reader will benefit from the concept and the mechanism of C-H activation with the relevant examples, which have been summarized herein with the various Ru based regioselective reactions through weak and strong coordination of metal and substrate.

The development of bacteria has been one of the most significant advances in medical science. The need for the development of novel antibacterial is clear, but the development of new antibacterial classes is more important. In this study, the new ruthenium complex bearing the NN chelating ligand 3,3'-dicarboxy-2,2'-bipyridine (3,3'-dcbpy) and the dimethylsulphoxide (DMSO) ligand, [Ru(3,3'-dcbpy) (DMSO)2Cl2], was synthesized and characterized using FT-IR, 1H- and 13C-NMR spectroscopy, elemental analysis, and UV-Vis spectrometry. In addition, the Ru-complex was examined for its activity as an antibacterial against gram-positive and gramnegative strains. Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentrations (MBCs) of the compound were assessed using sterile 96-well plates, in accordance with the Clinical and Laboratory Standards Institute. The results show that the compound shows a MIC value of 35 µg mL−1 against Staphylococcus aureus and 65 µg mL−1 against Escherichia coli with the bacteria's mode of action. In conclusion, Ru(3,3'-dcbpy) (DMSO)2Cl2 complex can be candidate as antibacterial agent against both gram-positive and gram-negative bacteria.

In recent years terpyridines (tpy) and mesoionic carbenes (MIC) have been widely used in metal complexes. With the right combination with a metal center, both of these ligands are individually known to generate excellent catalysts for CO2reduction. In this study, we combine the potentials of PFC (PFC=polyfluorocarbon) substituted tpy and MIC ligands within the same platform to obtain a new class of complexes, which we investigated with respect to their structural, electrochemical and UV/Vis/NIR spectroelectrochemical properties. We further show that the resulting metal complexes are potent electrocatalysts for CO2reduction in which CO is exclusively formed with a faradaic efficiency of 92 %. A preliminary mechanistic study, including the isolation and characterization of a key intermediate is also reported.

Rationally modulating the catalytic microenvironment is important for targeted induction of specific molecular behaviors to fulfill complicated catalytic purposes. Herein, a metal pre-chelating assisted assembly strategy is developed to facilely synthesize the hollow carbon spheres with ultrafine ruthenium clusters embedded in pore channels of the carbon shell (Ru@Shell-HCSs), which can be employed as nanoreactors with preferred electronic and geometric catalytic microenvironments for the efficient tandem hydrogenation of biomass-derived furfural toward 2-methylfuran. The channel-embedding structure is proved to confer the ultrafine ruthenium clusters with an electron-deficient property via a reinforced interfacial charge transfer mechanism, which prompts the hydrogenolysis of intermediate furfuryl alcohol during the tandem reaction, thus resulting in an enhanced 2-methylfuran generation. Meanwhile, lengthening the shell pore channel can offer reactant molecules with a prolonged diffusion path, and correspondingly a longer retention time in the channel, thereafter delivering an accelerated tandem hydrogenation progression. This paper aims to present a classic case that emphasizes the critical role of precisely controlling the catalytic microenvironment of the metal-loaded hollow nanoreactors in coping with the arduous challenges from multifunctional catalyst-driven complex tandem reactions.

A pair of ruthenium(II) complex enantiomers

A novel electrochemiluminescence (ECL) biosensor for hyaluronidase (HAase) based on the adjustable electrostatic interaction between the surface-charge-controllable nanoparticles and negatively charged electrode has been devised. Hyaluronic acid (HA)-coated amino-modified ruthenium bipyridine-doped silica nanoparticles (Ru@SiO

The interaction of four arene ruthenium complexes [(η6-p-cymene)Ru(Me2dppz)Cl]PF6 (1) with Me2dppz = 11,12-dimethyldipyrido[3,2-a:2′,3′-c] phenazine, [(η6-p-cymene)Ru(aip)Cl]PF6 (2) with aip = 2-(9-anthryl)-1H-imidazo[4,5-f][1,10] phenanthroline), ([(ƞ6-toluene)Ru(ppf)Cl]PF6) (3) and ([(ƞ6-pcymene) Ru(ppf)Cl]PF6) (4) with ppf = pyrido[2′,3′:5,6] pyrazino[2,3-f][1,10]phenanthroline with calf thymus DNA were investigated. All of four complexes exhibit DNA-binding activity. UV–Vis spectroscopic studies revealed the intrinsic binding constants of the order 104 M− 1 of magnitude, indicating non-intercalative mode. Fluorescence quenching analysis showed that all complexes interfere with intercalator ethidium bromide and minor groove binder Hoechst 33258 by a singular non-intercalative mode with extent that differs by two orders of magnitude. Gel electrophoresis results on DNA cleavage assay demonstrated that all complexes produced conformational changes of supercoiled circular plasmid pUC19 in concentration dependent way. The results of fluorescence titration bovine serum albumin by 1, 2, 3 and 4 showed that all complexes significantly quench tryptophan residues fluorescence through a static quenching mechanism. The antimicrobial activity against both Gram-positive and Gram-negative bacteria analyzed. Complex 1 was most active, even on Escherichia coli was more active than positive control compound.

Infection by the human immunodeficiency virus, which gives rise to acquired immunodeficiency syndrome, is still a major global health challenge, with millions of people being affected. The use of combination antiretroviral therapy has been a great success, leading to reduced mortality rates over the years. Although successful, these drugs are associated with various side effects, necessitating the development of new treatment strategies. This study investigated three metal-based complexes that were previously shown to possess some anticancer activity. The complexes were investigated against three pseudoviruses, which consisted of HIV-1 subtype C (CAP 210 and Du 156) and subtype A (Q 23). These complexes inhibited viral entry at low micromolar concentrations, with IC

Metal-catalyzed C

International audience; We describe an efficient catalytic strategy for enantio- and diastereoselective synthesis of homochiral β-CF3, β-SCF3, and β-OCF3 benzylic alcohols. The approach is based on dynamic kinetic resolution (DKR) with Noyori–Ikariya asymmetric transfer hydrogenation leading to simultaneous construction of two contiguous stereogenic centers with up to 99.9% ee, up to 99.9:0.1 dr, and up to 99% isolated yield. The origin of the stereoselectivity and racemization mechanism of DKR is rationalized by density functional theory calculations. Applicability of the previously inaccessible chiral fluorinated alcohols obtained by this method in two directions is further demonstrated: As building blocks for pharmaceuticals, illustrated by the synthesis of heat shock protein 90 inhibitor with in vitro anticancer activity, and in particular, needle-shaped crystals of representative stereopure products that exhibit either elastic or plastic flexibility, which opens the door to functional materials based on mechanically responsive chiral molecular crystals.

Herein, we report the development of a photoredox-initiated frontal ring-opening metathesis polymerization (FROMP) chemical system. We found that a ruthenium-based, bis

New mononuclear and dinuclear Ru(II) coordination compounds with the 2,7-bisbenzoimidazolyl-naphthyridine ligand have been synthesized and characterized by UV-vis, NMR, and MALDI-TOF. The molecular structures for Ru(II) compounds were determined by single-crystal X-ray diffraction. With the expansion of ligand π-conjugation and the increase in the complexed Ru number, the maximum emission wavelength red-shifted from 696 to 786 nm. The binding mode between complexes and DNA was predicted by molecular docking, which is intercalations and π-π stacking interactions with the surrounding bases. The intercalation mode of DNA binding was then determined by DNA titration and ethidium bromide (EB) displacement experiments. The antigrowth effects of complexes

Mobile phones have been used in combination with point of care (PoC) devices for over a decade now. However, their use seems restricted to the detection of sensing events using the video and camera functions. In contrast, the complementary ability to use mobile phones to power such PoC devices has been largely unexplored. This work demonstrates the proof-of-principle that a smartphone can be used to both power and analyze an electrochemiluminescence (ECL) detection system. A printed device is presented featuring an electrochemical cell connected in series to a rectenna that is able to use the Near Field Communication (NFC, 13.56 MHz) signal to provide the energy needed to generate ECL from Ru(bpy)

Phototherapy, such as photodynamic therapy (PDT) and photothermal therapy (PTT), refers to the therapeutic strategy using a visible or near-infrared (NIR) laser to generate free radicals or heat for noninvasive and localized tumor treatment. However, limited by the low photoconversion efficiency of therapeutic agents, a single treatment method can hardly lead to complete tumor ablation, even when enhancing the power density of the laser and/or prolonging the irradiation duration. In this work, copper ion and ruthenium complex codoped polydopamine nanoparticles (Cu(II)/LRu/PDA NPs) are designed for PDT/PTT dual-mode therapy. The doped LRu in the NPs can generate reactive oxygen species under visible laser irradiation and enable PDT. Because of the strong absorption in the NIR region, PDA can not only generate heat for PTT under irradiation but also be used for photoacoustic tomography (PAT) imaging. Meanwhile, the doping of Cu(II) in the NPs through the coordination with PDA facilitates T

Electron transport through biomolecules and in biological transport networks is of great importance to bioenergetics and biocatalysis. More generally, it is of crucial importance to understand how the pathways that connect buried metallocofactors to other cofactors, and to protein surfaces, affect the biological chemistry of metalloproteins. In terms of electron transfer (ET), the strongest coupling pathways usually comprise covalent and hydrogen bonded networks, with a limited number of through-space contacts. Herein, we set out to determine the relative roles of hydrogen bonds involved in ET via an established heme-to-surface tunneling pathway in cytochrome (cyt) c (i.e., heme-W59-D60-E61-N62). A series of cyt c variants were produced where a ruthenium tris(diimine) photooxidant was placed at position 62 via covalent modification of the N62C residue. Surprisingly, variants where the H-bonding residues W59 and D60 were replaced (i.e., W59F and D60A), showed no change in ET rate from the ferrous heme to Ru(III). In contrast, changing the composition of an alternate tunneling pathway (i.e., heme-M64-N63-C62) with the M64L substitution shows a factor of two decrease in the rate of heme-to-Ru ET. This pathway involves a through-space tunneling step between the heme and M64 residue, and such steps are usually disfavored. To rationalize why the heme-M64-N63-C62 is preferred, molecular dynamics (MD) simulations and Pathways analysis were employed. These simulations show that the change in heme-Ru ET rates is attributed to different conformations with compressed donor-acceptor distances, by ca. 2 Å in pathway distance, in the M64-containing protein as compared to the M64L protein. The change in distance is correlated with changes in the electronic coupling that are in accord with the experimentally observed heme-Ru ET rates. Remarkably, the M64L variation at the core of the protein translates to changes in cofactor dynamics at the protein surface. The surface changes identified by MD simulations include dynamic anion-π and dipole-dipole interactions. These interactions influence the strength of tunneling pathways and ET rates by facilitating decreases in through-space tunneling distances in key coupling pathways.

The first enantioselective ruthenium-catalyzed carbonyl vinylations via hydrogen auto-transfer are described. Using a ruthenium-JOSIPHOS catalyst, primary alcohols 2a-2m and 2-butyne 1a are converted to chiral allylic alcohols 3a-3m with excellent levels of absolute stereocontrol. Notably, 1°,2°-1,3-diols participate in site-selective C-C coupling occurs, enabling asymmetric carbonyl vinylation beyond premetalated reagents, exogenous reductants or hydroxyl protecting groups. Using 2-propanol as reductant, aldehydes dehydro-2a, 2l participate in highly enantioselective 2-butyne-mediated vinylation under otherwise identical reaction conditions. Regio-, stereo- and site-selective vinylations mediated by 2-pentyne 1b to form adducts 3n, 3o and epi-3o also are described. The tiglyl alcohol motif obtained upon butyne-mediated vinylation, which is itself found in diverse secondary metabolites, may be converted to commonly encountered polyketide stereodiads, -triads and -tetrads, as demonstrated by the formation of adducts 4a-4d. The collective mechanistic studies, including deuterium labelling experiments, corroborate a mechanism involving alcohol dehydrogenation to form a transient aldehyde and a ruthenium hydride, which engages in alkyne hydrometallation to form a nucleophilic vinylruthenium species that enacts carbonyl addition. A stereochemical model for carbonyl addition invoking formyl CH···I[Ru] and CH···O≡C[Ru] hydrogen bonds are proposed based on prior calculations and crystallographic data.

Ruthenium alkoxymethylidene complexes have recently come into view as competent species for metathesis copolymerization reactions when coupled with appropriate comonomer targets. Here, we explore the ability of Fischer-type carbenes to participate in cascade alternating metathesis cyclopolymerization (CAMC) through facile terminal alkyne addition. The combination of diyne monomers and an equal feed ratio of low-strain dihydrofuran leads to a controlled chain-growth copolymerization with high degrees of alternation (>97% alternating diads) and produces degradable polymer materials with low dispersities and targetable molecular weights. When combined with enyne monomers, this method is amenable to the synthesis of alternating diblock copolymers that can be fully degraded to short oligomer fragments under aqueous acidic conditions. This work furthers the potential for the generation of functional metathesis materials via Fischer-type ruthenium alkylidenes.

The examination of cross metathesis reactions leading to the desired product has been conducted to uncover computationally the origin of the chemo-, regio- and stereoselectivity. The comparison between the relative stabilities of all involved intermediates and products, together with the transition states, links to the probability for the respective pathway. Particularly, the respective transition states for each reaction tune the regio- and stereoselectivity because they define the energy barriers needed to be overcome to form the new olefin as final product. The broad range of studied reactions with the 2nd generation Grubbs catalysts allows concluding in detail the points to pay attention and thus helps to understand the chemo-, regio- and stereoselectivity in new olefin metathesis reactions. Here, a web-server joins all these mechanistic insights which is intended to support future predictive olefin metathesis catalysis.

Nanoscale ruthenium (Ru)-based materials are promising replacements for existing multilayered Cu interconnects in integrated circuits. However, it is not easy to apply the results of previously reported studies directly to the electrochemical damascene process because the previous studies have mainly focused on thin films by dry deposition. Here, we report the electrical resistivity and microstructure of electrodeposited Ru nanowires. We estimate that the resistivity value of a 10 nm diameter Ru nanowire to be 71.6 μΩ cm after analyzing the resistivity values of individual nanowires with various diameters. Furthermore, we investigate the electrical properties of RuxCo1-x nanowires where x is 0.04–0.99 at.% as possible replacements of the current TaN barrier structures. Over the entire composition range, the resistivity values of alloys are much lower than that of the conventional TaN. Additionally, Ru and Ru-alloy nanowires surrounded by dielectric silica are thermally stable after 450 °C heat treatment. Therefore, the nanoscale Ru and Ru-Co alloys possessing low resistivity values can be candidates for the interconnect and barrier materials, respectively.

Chlorate (ClO3-) is a common water pollutant due to its gigantic scale of production, wide applications in agriculture and industry, and formation as a toxic byproduct in various water treatment processes. This work reports on the facile preparation, mechanistic elucidation, and kinetic evaluation of a bimetallic catalyst for highly active ClO3- reduction into Cl-. Under 1 atm H2 and 20 °C, PdII and RuIII were sequentially adsorbed and reduced on a powdered activated carbon support, affording Ru0-Pd0/C from scratch within only 20 min. The Pd0 particles significantly accelerated the reductive immobilization of RuIII as >55% dispersed Ru0 outside Pd0. At pH 7, Ru-Pd/C shows a substantially higher activity of ClO3- reduction (initial turnover frequency >13.9 min-1 on Ru0; rate constant at 4050 L h-1 gmetal-1) than reported catalysts (e.g., Rh/C, Ir/C, Mo-Pd/C) and the monometallic Ru/C. In particular, Ru-Pd/C accomplished the reduction of concentrated 100 mM ClO3- (turnover number > 11,970), whereas Ru/C was quickly deactivated. In the bimetallic synergy, Ru0 rapidly reduces ClO3- while Pd0 scavenges the Ru-passivating ClO2- and restores Ru0. This work demonstrates a simple and effective design for heterogeneous catalysts tailored for emerging water treatment needs.

International audience; The trans-mer-[(kappa(2)-N,S-NS2C7H4)PR3Ru{kappa(3)-H,S,S '-H2B (NS2C7H4)(2)}], (trans-mer-1 a: R=Cy; trans-mer-1 b: R=Ph) complexes are kinetically controlled products that upon thermolysis led to the formation of cis-mer-[(kappa(2)-N,S-NS2C7H4)PR3Ru{kappa(3)-H,S,S '-H2B(NS2C7H4)(2)}], (cis-mer-2 a: R=Cy; cis-mer-2 b: R=Ph) and cis-fac-[(kappa(2)-N,S-NS2C7H4)PR3Ru{kappa(3)-H,S,S '-H2B(NS2C7H4)(2)}], (cis-fac-3 a: R=Cy; cis-fac-3 b: R=Ph) along with complex cis-[(kappa(2)-N,S-NS2C7H4)(2)Ru(PPh3)(2)], (cis-4). One of the main intentions of this study was to examine the flexibility of the borate and hemilabile N,S-chelating mercapto-benzothiazole ligands in adapting different spatial arrangements around metal center. Multinuclear spectroscopic analyses have been done to characterize all new complexes and the structures were further confirmed by single-crystal X-ray diffraction analysis. Further, Density Functional Theory (DFT) calculations were performed to provide an insight into the bonding of the complexes.

Ruthenium (Ru) complexes are developed as latent emissive photosensitizers for cancer and pathogen photodiagnosis and therapy. Nevertheless, most existing Ru complexes are limited as photosensitizers in terms of short excitation and emission wavelengths. Herein, we present an emissive Ru(II) metallacycle (herein referred to as 1) that is excited by 808-nm laser and emits at a wavelength of ∼1,000 nm via coordination-driven self-assembly. Metallacycle 1 exhibits good optical penetration (∼7 mm) and satisfactory reactive oxygen species production properties. Furthermore, 1 shows broad-spectrum antibacterial activity (including against drug-resistant Escherichia coli ) as well as low cytotoxicity to normal mammalian cells. In vivo studies reveal that 1 is employed in precise, second near-infrared biomedical window fluorescent imaging–guided, photo-triggered treatments in Staphylococcus aureus –infected mice models, with negligible side effects. This work thus broads the applications of supramolecular photosensitizers through the strategy of lengthening their wavelengths.

Alkyne containing natural products have been identified from plants, insects, algae, fungi, and bacteria. This class of natural products have been characterized as having a variety of biological activities. Polyynes are a sub-class of acetylenic natural products that contain conjugated alkynes and are underrepresented in natural product databases due to the fact that they decompose during purification. Here we report a workflow that utilizes alkyne azide cycloaddition (AAC) reactions followed by LC-MS/MS analysis to identify acetylenic natural products. In this report, we demonstrate that alkyne azide cycloaddition reactions with p-bromobenzyl azide result in p-bromobenzyl substituted triazole products that fragment to a common brominated tropylium ion. We were able to identify a synthetic alkyne spiked into the extract of Anabaena sp. PCC 7120 at a concentration of 10 μg/ml after optimization of MS/MS conditions. We then successfully identified the known natural product fischerellin A in the extract of Fischerella muscicola PCC 9339. Lastly, we identified the recently identified natural products protegenins A and C from Pseudomonas protegens Pf-5 through a combination of genome mining and RuAAC reactions. This is the first report of RuAAC reactions to detect acetylenic natural products. We also compare CuAAC and RuAAC reactions and find that CuAAC reactions produce less by-products compared to RuAAC but is limited to terminal alkyne containing compounds. In contrast, RuAAC is capable of identification of both terminal and internal acetylenic natural products, but by-products need to be eliminated from analysis by creation of an exclusion list. We believe that both CuAAC and RuAAC reactions coupled to LC-MS/MS represent a method for the untargeted identification of acetylenic natural products, but each method has strengths and weaknesses.

Preliminary explorations of the annihilation electrogenerated chemiluminescence (ECL) of mixed metal complexes have revealed opportunities to enhance emission intensities and control the relative intensities from multiple luminophores through the applied potentials. However, the mechanisms of these systems are only poorly understood. Herein, we present a comprehensive characterisation of the annihilation ECL of mixtures of tris(2,2'-bipyridine) ruthenium(II) hexafluorophosphate ([Ru(bpy)(3)](PF6)(2)) and fac-tris(2-phenylpyridine)iridium(III) ([Ir(ppy)(3)]). This includes a detailed investigation of the change in emission intensity from each luminophore as a function of both the applied electrochemical potentials and the relative concentrations of the two complexes, and a direct comparison with two mixed (Ru/Ir) ECL systems for which emission from only the ruthenium-complex was previously reported. Concomitant emission from both luminophores was observed in all three systems, but only when: (1) the applied potentials were sufficient to generate the intermediates required to form the electronically excited state of both complexes; and (2) the concentration of the iridium complex (relative to the ruthenium complex) was sufficient to overcome quenching processes. Both enhancement and quenching of the ECL of the ruthenium complex was observed, depending on the experimental conditions. The observations were rationalised through several complementary mechanisms, including resonance energy transfer and various energetically favourable electron-transfer pathways. Refereed/Peer-reviewed

A new tetrapyridine ligand, 5,5′-(3-pyridyl)-2,2′-bipyridine (2) was prepared from 5,5′-dibromo-2,2′-bipyridine (1) via Pd(0)-mediated Suzuki coupling. The reaction was performed either directly upon the free ligand, or upon its Ru(II) complex. The structures of [Ru(1)3](PF6)2 and [Ru(2)3](PF6)2 were studied in solution by NMR, and in the solid state by single crystal X-ray diffraction. Solution NMR data suggests distorted structures, consistent with the observed slow reactivity of the ligands towards Ru(II) ions, and their reluctance to coordinate to Fe(II) ions. However, solid-state X-ray data indicated little distortion from ideal geometries, suggesting the effect may be more electronic than steric in nature.

This thesis discusses the binding of alkanes (saturated hydrocarbons) to transition metal complexes. The thesis describes: (i) the first direct Nuclear Magnetic Resonance (NMR) spectroscopic observation of alkane coordination to group 8 transition metal centres; (ii) the only complete group of analogous transition metal alkane σ-complexes (Fe, Ru and Os); and (iii) the first set of methane σ-complexes, formed from molecular methane, that are sufficiently stable to analyse using NMR spectroscopy. Chapter 1 is a general introduction for the non-specialist, introducing the concepts of coordination chemistry and in particular the formation of σ-complexes including complexes of molecular hydrogen and alkanes. Chapter 2 contains an introduction to methane in organometallic chemistry and describes results from low temperature NMR spectroscopic and computational investigations into the methane σ-complexes [η5-CpM(CO)2(CH4)][Al(OC(CF3)3)4] (M = Os (5), Ru (13), Fe (17)) that were produced using an improved in situ NMR sample photolysis apparatus. The bound methane fragments in 5, 13 and 17 have 1H resonances at δ −2.16, δ −2.10 and δ −4.27; 13C resonances at δ −56.3, δ −48.8, and δ −53.0; and 1J C-H couplings of 127 Hz, 126 Hz, and 126 Hz respectively. Of these three species, 13 is the least stable and 5 is the most stable. DFT and ab initio calculations provide further insight into the structures of the [η5-CpM(CO)2(CH4)]+ (M = Os (5), Ru (13) and Fe (17)) complexes and find that the binding free energies of 5, 13 and 17 are -13.6 kcal mol- 1, -10.5 kcal mol-1 and -11.7 kcal mol-1 respectively. Chapter 3 describes results from the low temperature NMR spectroscopic and computational investigations into the ethane σ-complex [η5-CpOs(CO)2(C2H6)][Al(OC(CF3)3)4] (19). The proton resonances, at δ −2.39 (for the osmium-bound CH3) and δ 1.32 (for and the non-bound CH3) were correlated to 13C resonances at δ −30.7 and δ 11.1 respectively. DFT calculations support the observation that there is no exchange observed between the bound and non-bound methyl groups at temperatures as high as -75 ℃, with calculations predicting the barrier to exchange to be a relatively high value of 13.7 kcal mol-1. NMR data show that 19 is more stable than the methane analogue 5, discussed in Chapter 2, consistent with the free energy of binding being calculated to be higher in the case of the ethane complex (-16.6 kcal mol-1). Chapter 4 describes results from the low temperature NMR spectroscopic investigations into the cyclopentane σ-complexes [η5-CpM(CO)2(c-C5H10)][Al(OC(CF3)3)4] (M = Os (20), Ru (22), Fe (23)). The cyclopentane σ-complexes show the same trend in stability as was reported for the methane complexes (20 > 23 > 22). The osmium centred cyclopentane σ-complex (20) is the most stable of the cyclopentane σ-complexes studied here and is sufficiently stable to be observed in solution for a short period (t1/2 = 7.8 mins) at temperatures as high as -50 ℃, making it one of the most stable alkane σ-complexes to be studied in the solution state. Chapter 5 describes preliminary results from the low temperature NMR spectroscopic investigation into the n -pentane σ- complexes [η5-CpM(CO)2(n -C5H12)][Al(OC(CF3)3)4] (M = Os (24) and Ru (25)). NMR data show that the osmium complex preferentially binds methyl groups during UV irradiation, but in the dark the methyl-bound species isomerises to preferentially bind the methylene groups. The ruthenium complex (25) shows a preference to bind via methylene groups under all conditions examined. Chapter 6 draws some overarching conclusions from the investigations presented in this thesis and gives some suggestions to direct future studies in this field. Chapter 7 describes the design and production of an improved experimental apparatus for conducting in situ photolysis of NMR samples with added gaseous reagents and describes the experimental procedures and synthesis of precursor compounds.

The role of metal complexes on facing DNA has been a topic of major interest. However, metallonitrosyl compounds have been poorly investigated regarding their reactivities and interaction with DNA. A nitrosyl compound, cis-[Ru(bpy)

Mononuclear Ru(II)Polypyridyl complexes of type [Ru(A)