Volatility of ruthenium during heating of a residue containing calcium phosphate

By heating a residue attained by the evaporation of a solution containing calcium phosphate, ruthenium and nitric acid, ruthenium volatilizes. The amount of ruthenium volatilized /both carrier-free¹⁰⁶Ru and milligram amounts of ruthenium/ depends on the composition of the solution before evaporation, on the temperature and time of residue heating. At 500 °C up to 90% of ruthenium can volatilize within six min.     

On the volatility of ruthenium

When annealing the evaporation residue formed by evaporating a solution containing ruthenium, phosphates and nitrates, ruthenium volatilizes. The amount of volatilized ruthenium (both¹⁰⁶Ru traces and milligram amuonts of Ru) depends on the solution composition before evaporation and on the temperature and time of annealing. Volatility occurs at a temperature as low as 300°C. We suppose that the volatility is due to thermal decomposition of the ruthenium compounds with phosphates. The released atoms of ruthenium are oxidized by the decomposition products of the nitrate. The formation of complex compounds of ruthenium with phosphates during the evaporation of the solution follows from the data of elemental and spectral analysis and ion exchange chromatography.     

钌宝宝的自荐信——我是抗癌小战士

Using the anthropomorphic approach, this article introduces the discovery history of ruthenium elements in the first person role, and focuses on the ruthenium complexes as important therapeutic agents for cancer treatment. We have focused our attention on KP1019 incorporating ruthenium ions complexes which have been already used in clinical or have been advanced to clinical trials as anticancer agents. Moreover, the half-sandwich ruthenium and ruthenium polypyridine complexes drugs are also reviewed.     

Ruthenium-catalyzed Heck-type olefination and Suzuki coupling reactions: studies on the nature of catalytic species

Ruthenium-catalyzed Heck olefination and Suzuki cross coupling reactions have been developed. When starting with a ruthenium complex [RuCl(2)(p-cymene)](2) as a homogeneous catalyst precursor, induction periods were observed and ruthenium colloids of zero oxidation state were generated under catalytic conditions. Isolated ruthenium colloids carried out the olefination, implying that active catalytic species are ruthenium nanoclusters. To support this hypothesis, ruthenium nanoparticles stabilized with dodecylamine were independently prepared via a hydride reduction procedure, and their catalytic activity was subsequently examined. Olefination of iodobenzene with ethyl acrylate was efficiently catalyzed by the ruthenium nanoparticles under the same conditions, which could be also reused for the next runs. In poisoning experiments, the conversion of the olefination was completely inhibited in the presence of mercury, thus supporting our assumption on the nature of catalytic species. No residual ruthenium was detected from the filtrate at the end of the reaction. On the basis of the postulation, a heterogeneous catalyst system of ruthenium supported on alumina was consequently developed for the Heck olefination and Suzuki cross coupling reactions for the first time. It turned out that substrate scope and selectivity were significantly improved with the external ligand-free catalyst even under milder reaction conditions when compared to results with the homogeneous precatalyst. It was also observed that the immobilized ruthenium catalyst was recovered and reused up to several runs with consistent efficiency. Especially in the Suzuki couplings, the reactions could be efficiently carried out with as low as 1 mol % of the supported catalyst over a wide range of substrates and were scaled up to a few grams without any practical problems, giving coupled products with high purity by a simple workup procedure.     

金属钌配合物的抗肿瘤活性及其作用机理

金属配合物在医药领域起着重要的作用,金属钌配合物在抗肿瘤活性研究方面取得了重要的进展.结合本组的研究工作,本文对金属钌配合物在抗肿瘤活性以及抗肿瘤作用机制方面的研究进展进行了综述.     

活性炭负载钌系氨合成催化剂中钌含量的分析

采用分光光度法测定活性炭负载钌系氨合成催化剂中的钌含量．在强酸和乙醇体系中,Ru（Ⅲ）与硫脲生成蓝色物,于最大吸收波长λ=620am处测定催化剂中的钌含量．测试结果表明,该方法操作简单、干扰小,相对标准偏差为1％～3％,加标回收率在97．5％～102．0％之间,适用于活性炭负载钌系氨合成催化剂中钌含量的准确测定．     

Conversion of oxido-bridged dinuclear ruthenium complex to dicationic dinitrosyl ruthenium complex using proton and nitric oxide: completion of NO reduction cycle

The hydroxido-bridged dinuclear ruthenium complex 4, which is supported by Tp ligands, has been prepared from protonation of the oxido-bridged dinuclear ruthenium complex 3. Additional protonation of 4, affording the aqua-bridged dinuclear ruthenium complex 5 in situ, and subsequent treatment with NO gave rise to the dicationic dinitrosyl complex 2. These indicate completion of the NO reduction cycle on the dinuclear ruthenium complex.     

Targeted and multifunctional arene ruthenium chemotherapeutics

The introduction of multifunctionalities for tumour targeting is becoming a popular strategy toward the development of new therapeutic agents. In particular, the multifaceted potential of ruthenium(II)-arene complexes show great promise as chemotherapeutics. An ever-increasing number of papers dealing with the integration of ruthenium complexes with biologically active molecules to derive bioorganometallic molecules of chemotherapeutic significance have been published in recent years. This perspective review presents a short overview of multifunctional ruthenium-based drugs, especially those containing arene ruthenium complexes, with the emphasis on the combination of photosensitizers with ruthenium complexes for the preparation of novel multifunctional photodynamic therapy agents.     

Determination of ruthenium and iridium in anode coatings by atomic-absorption spectroscopy

A method is described for the determination of ruthenium and iridium coated on an electrode surface. The coating is chemically removed from the electrode by fusion with alkali, and the resulting solution prepared for analysis. Interelement interferences are eliminated by using a titanium-potassium matrix solution as a releasing agent. Recovery and precision data are given for ruthenium and iridium. The AAS determination of ruthenium compares favourably with a standard colorimetric method.     

Ruthenium complexes bearing bidentate Schiff base ligands as efficient catalysts for organic and polymer syntheses

A concise overview is given on mononuclear and dinuclear, bidentate Schiff base ruthenium complexes with different additional ligands and on their applications in various chemical transformations such as Kharasch addition, enol-ester synthesis, alkyne dimerization, olefin metathesis and atom transfer radical polymerization. These new ruthenium complexes, conveniently prepared from commonly available ruthenium compounds, are very stable, exhibit a good tolerance towards organic functionalities, air and moisture and display high activity and chemoselectivity in chemical transformations. Relevant features of coordination chemistry connected with the reaction mechanism and chemoselectivity are also fully described. Since the nature of Schiff bases can be changed in a variety of ways, appealing routes for designing and preparing novel ruthenium complexes can be foreseen in the future.     

Ruthenium‐catalyzed cyclizations of enynes via a ruthenacyclopentene intermediate: Development of three novel cyclizations controlled by a substituent on alkyne of enyne

Three novel ruthenium‐catalyzed cyclizations of enynes were developed. In each cyclization, a ruthenacyclopentene derived from enyne and Cp*RuCl(cod) is a common intermediate. When an enyne having an alkyl, an ester, or a formyl group on an alkyne was reacted with Cp*RuCl(cod) under ethylene gas, ethylene was inserted into the ruthenium‐sp² carbon bond of ruthenacyclopentene to afford ruthenacycloheptene, and β‐hydrogen elimination followed by reductive elimination occurred to give a cyclic compound having a 1,3‐diene moiety. When an acyl group was placed on the alkyne, the carbonyl oxygen coordinated to the ruthenium metal of ruthenacyclopentene to produce a ruthenium carbene complex, which reacted with ethylene to give a cyclic compound having a cyclopropane ring on the substituent. On the other hand, when the substituent on the alkyne was pent‐4‐enyl, insertion of an alkene part into ruthenacyclopentene followed by reductive elimination gave a tricyclic compound by a ruthenium‐catalyzed [2 + 2 + 2] cyclization of diene and an alkyne. DOI 10.1002/tcr.201100003     

Functionalization of Alkynes by a (Salen)ruthenium(VI) Nitrido Complex

Exploring new reactivity of metal nitrides is of great interest because it can give insights to N₂ fixation chemistry and provide new methods for nitrogenation of organic substrates. In this work, reaction of a (salen)ruthenium(VI) nitrido complex with various alkynes results in the formation of novel (salen)ruthenium(III) imine complexes. Kinetic and computational studies suggest that the reactions go through an initial ruthenium(IV) aziro intermediate, followed by addition of nucleophiles to give the (salen)ruthenium(III) imine complexes. These unprecedented reactions provide a new pathway for nitrogenation of alkynes based on a metal nitride.     

Extraction of ruthenium thiocyanate and its separation from rhodium by polyurethane foam

Conditions for the formation and extraction of the thiocyanate complex of ruthenium are reported. Distribution coefficients of more than 10(4) and a capacity of about 0.24 mole per kg of foam were obtained. The effect of the chloride salts of various univalent cations on the extraction of Ru(SCN)(6)(3-) indicated that the efficiency of ruthenium extraction depends on how well the cation fits into the polyether segment of the polyurethane foam, which agrees with the "cation-chelation" mechanism. The separation of ruthenium and rhodium indicated that more than 95% of the rhodium remained in the aqueous phase and about 95% of the ruthenium was retained by the polyurethane foam and could be easily recovered.     

A DFT Study on the Reaction Pathways for Carbon?Carbon Bond‐Forming Reactions between Propargylic Alcohols and Alkenes or Ketones Catalyzed by Thiolate‐Bridged Diruthenium Complexes

The reaction pathways of two types of the carbon? carbon bond‐forming reactions catalyzed by thiolate‐bridged diruthenium complexes have been investigated by density‐functional‐theory calculations. It is clarified that both carbon? carbon bond‐forming reactions proceed through a ruthenium–allenylidene complex as a common reactive intermediate. The attack of π electrons on propene or the vinyl alcohol on the ruthenium–allenylidene complex is the first step of the reaction pathways. The reaction pathways are different after the attack of nucleophiles on the ruthenium–alkynyl complex. In the reaction with propene, the carbon? carbon bond‐forming reaction proceeds through a stepwise process, whereas in the reaction with vinyl alcohol, it proceeds through a concerted process. The interactions between the ruthenium–allenylidene complex and propene or vinyl alcohol have been investigated by applying a simple way of looking at orbital interactions.     

The formation and reduction of anodic films on electrodeposited ruthenium

The formation and reduction of anodic films on bright ruthenium was investigated using substrates prepared by electrodeposition onto gold-plated platinum from a commercial ruthenium bath operated at 70°C. Anodic films formed on the ruthenium may be reduced by maintaining the electrode at potentials below 0.2 V. The reduction behaviour was markedly affected by the anodization potential and, at short times, by the period of anodization. The bell-shaped cathodic current-time curves observed with films produced at potentials in the region of 1.2 V, suggest that the process in this case involves nucleation of reduction centres on a relatively stable surface layer. The influence of potential, time, and both the concentration and nature of the electrolyte on the extent of anodic film formation was investigated. The results are discussed in terms of the formation of stable phase oxides in the relatively thick anodic film produced on the ruthenium surface.     

New method for facile synthesis of amphiphilic thiol-stabilized ruthenium nanoparticles and their redox-active ruthenium nanocomposite

The one-phase reduction of RuCl3 with lithium triethylborohydride as a reductant in tetrahydrofuran in the presence of 1-octanethiol, 1-octadecanethiol, 1,1'-binaphthalene-2,2'-dithiol, or oligoethyleneoxythiol gave organic solvent- and water-soluble thiol-stabilized ruthenium nanoparticles. The oligoethyleneoxythiol-stabilized ruthenium nanoparticles were soluble in both water and organic solvents. The ruthenium nanoparticles were stable in the solid state and did not aggregate in solution. Transmission electron microscope images of the ruthenium nanoparticles reveal small dispersed particles with a narrow size distribution. The ligand-exchange reaction of octadecanethiol-stabilized ruthenium nanoparticles (2.0 nm) with phenothiazine-linked decanethiol afforded redox-active phenothiazine-functionalized ruthenium nanoparticles (1.9 nm) that showed a reversible redox peak at +0.51 V (vs Ag/0.1 M AgNO3) in the cyclic voltammogram.     

Synergy between the metal nanoparticles and the support for the hydrogenation of functionalized carboxylic acids to diols on Ru/TiO2

Ruthenium nanoparticles supported on titania are over three times more active than conventional ruthenium on carbon for the hydrogenation of lactic acid. This superior catalytic activity can be due to a combined action of small ruthenium nanoparticles and the titania support.     

Catalytic effects of ruthenium and osmium spontaneous deposition on platinum surfaces toward methanol oxidation

The influence of ruthenium and osmium spontaneous deposition on polycrystalline platinum in sulfuric acid was studied by conventional electrochemical techniques. The inhibition of the hydrogen adatom voltammetric profile by the foreign adatoms was used to calculate the degree of surface coverage of ruthenium, osmium, and a mixture of both metal ions from solutions of different composition. Methanol adsorption and oxidation were compared on bare platinum, platinum/ruthenium, platinum/osmium, and ternary compounds, considering the efficiency of methanol oxidation per hydrogen adatom displaced by the foreign metal on platinum.     

Synthesis and optical properties of bifunctional thiophene molecules coordinated to ruthenium

A series of unsymmetrical bi- and tetrathiophenes have been synthesized with bipyridine and phosphonic acid functional groups. To do this, phosphonic esters were bonded to thiophenes and the thiophenes coupled to bipyridine. After synthesis of the thienylbipyridines, bis(bipyridine) ruthenium was coordinated to them through the bipyridines. The thienylbipyridines absorb visible light and fluoresce; however, on attachment to ruthenium, both their fluorescence and that of ruthenium are quenched. An additional effect of coordinating ruthenium to the thiophenes is a new absorption band around 470 nm. Variation in oligothiophene length and bipyridine substitution position allowed comparison of the effect of these variables on electronic properties. The longer oligothiophenes display lower-energy absorptions and emissions than that of the shorter thiophenes. In contrast, the position of the bipyridine attachment does not have a large effect on the absorbance or emission wavelength, or on the fluorescence quantum yield.     

Two-dimensional ruthenium nanoparticles between graphite layers: The effect of reduction temperature

A mixture of graphite powder and ruthenium chloride (III) anhydrous was treated at 723 K under 0.3 MPa chlorine for 3 days, followed by reduction under 40 kPa of hydrogen for 1 h to produce ruthenium metal particles intercalated between graphite layers (Ru-GIC). The structures of ruthenium particles depended on the reduction temperatures. Sheet-like ruthenium particles with 1–3 nm thickness and 10 to several hundred nm width containing numerous irregularly shaped holes with round edge, were formed by reduction at 573 K. A Ru-GIC sample treated at 653 K possessed two-dimensional ruthenium nanosheets with hexagonal holes (straight lines intersect at an angle of 120°) in a similar range of thickness and width. On the other hand, Ru-GIC samples reduced at 773 and 823 K showed two-dimensional plate morphology with a thickness of 1–4 nm. In addition, ruthenium nanoparticles supported on the graphite surface (Ru/Gmix) were also prepared from a slurry of ruthenium chloride (III) hydrate and graphite powder by impregnation and hydrogen reduction. The ruthenium particles in Ru/Gmix were spherical at about 3.6 nm, and the reduction temperature did not affect their particles size. Both Ru-GIC and Ru/Gmix samples were evaluated for cinnamaldehyde (CAL) hydrogenation in supercritical carbon dioxide solvent at 323 K, and they were active to produce cinnamyl alcohol (COL) and hydrocinnamaldehyde (HAL). However, Ru-GIC samples showed higher COL selectivity than Ru/Gmix prepared at the same reduction temperature, and COL selectivity over Ru-GIC increased with the reduction treatments at 773 and 823 K.