Ruthenium Derivatives Research Articles

Rhodium or ruthenium units peripherally coordinated to carbosilane dendrimers functionalized with P-stereogenic monophosphines

Carbosilane dendrimers containing P-stereogenic monophosphines as terminal groups, Dend-{CH 2PPhR} n (R = 2-biphenylyl or 9-phenanthryl), were reacted with [RhCl(COD)] 2 or [RuCl 2( p-cymene)] 2 to afford the corresponding chiral metalladendrimers Dend-{CH 2PPhR(RhCl(COD))} n or Dend-{CH 2PPhR(RuCl 2( p-cymene))} n , respectively. Attempts to obtain the first generation Ru-dendrimer for R = 2-biphenylyl proved unsuccessful, probably due to the steric hindrance of R. Complete characterization of these species was achieved by multinuclear NMR spectra, including 2D experiments, mass spectrometry, and optical rotation determinations. The catalytic properties of the rhodium dendrimers were tested in the hydrogenation of dimethylitaconate and those of the ruthenium derivatives in the asymmetric hydrogen transfer of acetophenone. The following model chiral compounds, (CH 3) 3Si{CH 2PPhR(RhCl(COD))} and (CH 3) 3Si{CH 2PPhR(RuCl 2( p-cymene))}, were prepared in order to detect potential dendritic effects. All compounds were active in the catalytic conditions tested, but low or null e.e. were found.

Similarities and Contrasts between Silyl and Stannyl Derivatives of Ruthenium and Osmium

Silyl and stannyl complexes of ruthenium and osmium bearing halogen substituents on the silicon and tin atoms undergo many interesting reactions. While there are formal similarities, there are also marked differences between these silyl and stannyl derivatives. This review first surveys the synthetic approaches we have developed to the silyl and stannyl complexes that involve oxidative addition of halogenated silanes coupled with reductive elimination for the preparation of the silyl complexes LnM(SiRnX3-n) (M = Ru, Os) and reaction between LnMH and the vinylstannane R3SnCHCH2 to give first the triorganostannyl complexes LnM(SnR3) (M = Ru, Os), which are then functionalized by redistribution reactions to give LnM(SnRnX3-n) (M = Ru, Os). Among the unusual compounds derived from these halogenated silyl and stannyl complexes are derivatives with the following novel ligands: Si(OH)3, Sn(OH)3, silatranyl, stannatranyl, SnH3, and SnMe2SnPh3. A contrast between the osmasilanol LnOs(SiMe2OH) and the osmastannol LnOs(SnMe2OH) is that the former deprotonates to a silanolate anion, [LnOs(SiMe2O)]-, while the latter, when treated with base, ortho-stannylates a triphenylphosphine ligand. Another contrast is provided by the ease with which osmium trimethylstannyl complexes undergo α-methyl migration reactions.

Bimetallic complexes with ruthenium and tantalocene moieties: Synthesis and use in a catalytic cyclopropanation reaction

The reaction of the tantalocene dichloride monophosphines ( 1– 2) with the binuclear complex [( p-cymene)RuCl 2] 2 gives the heterobimetallic compounds ( p-cymene)[(η 5-C 5H 5)(μ-η 5:η 1-C 5H 4(CH 2) 2PR 2)TaCl 2]RuCl 2 ( 3– 4). The air oxidation of these bimetallic species 3– 4, leads to the cationic hydroxo tantalum ruthenium derivatives 5– 6. The last ones are easily deprotonated by a base to afford the oxo analogues 7– 8. A preliminary assessment in catalytic cyclopropanation of styrene with tantalum ruthenium bimetallic complexes 3– 8 as precatalysts revealed a cooperative effect with a subtle role of the early metal fragment.

Synthesis and Reactivity of [Ru(Cp*)(L)(MeCN)2][PF6] (L = Ph2POMe or Ph2P‐o‐tolyl) and {Ru(Cp*)[Ph2PCH2C(tBu)=O](MeCN)}[PF6] Complexes, Their Involvement as Catalyst Precursors for Regioselective Allylic Substitution Reactions and Related [Ru(Cp*)Cl(Ph2POMe)(RCHCHCH2)][PF6] η3‐Allyl Ruthenium(IV) Intermediates

AbstractThe synthesis of the new complexes [Ru(Cp*)(L)(MeCN)2][PF6] (L = Ph2POMe or Ph2P‐o‐tolyl) and {Ru(Cp*)[Ph2PCH2C(tBu)=O](MeCN)}[PF6] (2a–c) is achieved starting from [Ru(Cp*)(MeCN)3][PF6]. The acetonitrile ligands in complexes 2a–c are labile, as emphasised by the easy formation of {Ru(Cp*)(CO)2[Ph2PCH2C(=O)tBu]}[PF6] (3). The keto‐phosphane is used as a tool to convert 3 into {Ru(Cp*)(CO)[Ph2PCH2C(tBu)=O]}[PF6] (5). Complex 5 reacts with 1,1‐diphenyl‐2‐propyn‐1‐ol in methanol as solvent toafford the vinyl‐carbene complex {Ru(Cp*)(CO)[=C(OMe)CH=CPh2][Ph2PCH2C(=O)tBu]}[PF6]. The new η3‐allyl ruthenium(IV) derivatives [Ru(Cp*)Cl(Ph2POMe)(CH2CMeCH2)][PF6] and [Ru(Cp*)Cl(Ph2POMe)(RCHCHCH2)][PF6] (R = Me; nPr, 8d; or Ph, 8e) are obtained by reacting 2a with the appropriate allylic halide. The X‐ray crystal structure determination of the compounds 8d and 8e disclosed an endo‐trans‐RCHCHCH2 η3‐allyl ligand. The formation of branched allyl aryl ethers is regioselectively favoured when complexes 2a–c are involved as catalyst precursors for the etherification of cinnamyl chloride, chlorohexene and 3‐chloro‐4‐phenylbut‐1‐ene with phenol, p‐methoxyphenol, cresols and (o or p)‐chlorophenols, in the presence of K2CO3. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Solid-supported chemiluminescence and electrogenerated chemiluminescence based on a tris(2,2′-bipyridyl)ruthenium(ii) derivative

We report a simple and efficient technique for the covalent immobilisation of a tris(2,2'-bipyridyl)ruthenium(II) derivative suitable for both chemiluminescence and electrochemiluminescence detection.

Functional Microporous Materials of Metal Carboxylate: Gas‐Occlusion Properties and Catalytic Activities

AbstractFor Abstract see ChemInform Abstract in Full Text.

Oxygenation of a Ruthenium(II) Thiolate to a Ruthenium(II) Sulfinate Proceeds via Ruthenium(III)

Exposure of acetonitrile/methanol solutions of [PPN][Ru(DPPBT)3] [PPN = bis(triphenylphosphoranylidene); DPPBT = 2-diphenylphosphinobenzene thiolate] to oxygen initiates metal-centered oxidation, yielding the ruthenium(III) thiolate Ru(DPPBT)3. Ru(DPPBT)3 further reacts with oxygen, at sulfur, to give the ruthenium(III) sulfinate complex [Ru(DPPBT-O2)2(DPPBT)], which is reduced under ambient conditions to [PPN][Ru(DPPBT-O2)2(DPPBT)]. Ruthenium(II) sulfinate is the only product isolated from acetonitrile/methanol. Yellow crystals of [PPN][Ru(DPPBT-O2)2(DPPBT)] were obtained. Ruthenium(III) sulfinate was isolated as green prism-shaped crystals upon oxygenation of [PPN][Ru(DPPBT)3] in chlorobenzene/hexane. Electrochemical oxidation of ruthenium(II) sulfinate yields the ruthenium(III) derivative, which is rapidly reduced back to ruthenium(II) upon the addition of hydroxide.

Functional microporous materials of metal carboxylate: Gas-occlusion properties and catalytic activities

Copper(II) terephthalate is the first transition metal complex found capable of adsorbing gases. This complex has opened the new field of adsorbent complex chemistry. It is recognized as the lead complex in the construction of microporous complexes. This specific system has been expanded to a systematic series of derivatives of other isomorphous transition metals, molybdenum(II), ruthenium(II, III), and rhodium(II). These complexes with open frameworks are widely recognized as very useful materials for applications to catalysis, separation at molecular level, and gas storage.

A Mechanistic Study on Alcohol Oxidations with Oxygen Catalysed by TPAP‐Doped Ormosils in Supercritical Carbon Dioxide

AbstractThe heterogeneous oxidation of various alcohols with oxygen catalysed by TPAP‐doped ormosils in scCO2 at 75 °C and 22.0 MPa has been studied in detail. Sol‐gel segregation of TPAP into the inner porosity of an organically modified silica (ormosil) xerogel along with the use of a reaction medium which does not dissolve the catalyst, prevents aggregation of oxidation‐inactive ruthenium derivatives without the need of chemical tethering. Thus, at least 140 TONs may be obtained in the oxidation of primary alcohols with the formation of aldehydes as sole reaction products. Investigation of the oxidation mechanism shows that the catalytic process exhibits a first‐order dependence on the amount of catalyst, a fractional order on the alcohol concentration and a negative order for oxygen pressures higher than 0.2 bar. Evidence is presented for an associative oxidation mechanism simultaneously involving TPAP, organic substrate and oxygen.

Picosecond Dynamics of Nonthermalized Excited States in Tris(2,2-bipyridine)ruthenium(II) Derivatives Elucidated by High Energy Excitation

The picosecond excited-state dynamics of several derivatives have been investigated using high photon energy excitation combined with picosecond luminescence detection. Instrument response-limited fluorescence (tau(1) approximately equal to 3-5 ps) at 500 nm was observed for all of the complexes, while longer-lived emission (tau(2) > 50 ps), similar in energy, was observed for only some of the complexes. Interestingly, the presence of tau(2) required substitution at the 4,4-positions of the bipyridine ligands and D(3) symmetry for the complex; only the 4,4-substituted homoleptic complexes exhibited tau(2). On the basis of previous assignments of the ultrafast dynamics measured for Ru(bpy)(2+)3 and Ru(dmb)(2+)3, tau(2) has been tentatively ascribed to relaxation from higher electronic or vibrational levels in the triplet manifold having slightly more triplet character than the state responsible for tau(1). However, given that the kinetics for these transition metal complexes are highly dependent on both pump and probe wavelengths and that there is considerable interest in utilizing such complexes for electron transfer in the nonergodic limit, further characterization of the state giving rise to tau(2) is warranted.

Second-order optical effects in organometallic nanocomposites induced by an acoustic field

Acoustically stimulated second-order optical effects in Ru-derivative nanocomposites were discovered. The alkynyl ruthenium derivatives were embedded in a polymethyl methacrylate (PMMA) polymer matrix. As second-order optical effects we studied second-harmonic generation (SHG) and linear electro-optics (LEO) phenomena. The physical insight of the effect observed consists in a coexistence of nanocofined chromophore levels and localized $d$ states of ruthenium. A transverse acoustic field favors the occurrence of charge density noncentrosymmetry required for observation of the second-order optical effects, particularly SHG. We have found that acoustically induced SHG and LEO for fundamental YAB-${\mathrm{Gd}}^{3+}$ laser light $(\ensuremath{\lambda}=1.76\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m})$ increases and achieves a maximum value at acoustic power density of about $1.45\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$. The values of the SHG for several Ru chromophores were higher than those for well-known inorganic crystals. With decreasing temperature, the SHG signal strongly increases below 55 K and correlates well with occurrence of ``softlike'' low-frequency anharmonic quasiphonon modes responsible for the phase transitions. The SHG maxima were observed at acoustic frequencies of about 13 kHz. Increasing of acoustical frequencies up to the megahertz range suppresses the observed phenomena. Comparing the obtained results with the acoustically induced Raman spectra at different temperatures one can conclude that the observed effects are due to acoustically induced electron-vibration anharmonicity, and are observed at temperatures below 55 K. Varying the chromophore content within the embedded matrices we were able to use effective nanoparticle sizes within the range 5--60 nm. It is clearly shown that the enhancement of the effective nanosize effectively suppresses the observed second-order optical effects.

Crosslinking Photosensitized by a Ruthenium Chelate as a Tool for Labeling and Topographical Studies of G-Protein-Coupled Receptors

The purpose was to apply oxidative crosslinking reactions to the study of recognition and signaling mechanisms associated to G-protein-coupled receptors. Using a ruthenium chelate, Ru(bipy)(3)(2+), as photosensitizer and visible light irradiation, in the presence of ammonium persulfate, we performed fast and efficient covalent labeling of the B(2) bradykinin receptor by agonist or antagonist ligands possessing a radio-iodinated phenol moiety. The chemical and topographical specificities of these crosslinking experiments were investigated. The strategy could also be applied to the covalent labeling of the B(1) bradykinin receptor, the AT(1) angiotensin II receptor, the V(1a) vasopressin receptor and the oxytocin receptor. Interestingly, we demonstrated the possibility to covalently label the AT(1) and B(2) receptors with functionalized ligands. The potential applications of metal-chelate chemistry to receptor structural and signaling studies through intramolecular or intermolecular crosslinking are presented.

Synthesis of phthalocyanines with two carboxylic acid groups and their utilization in solar cells based on nano-structured TiO2

A way of anchoring unsymmetrical phthalocyaninato-metal complexes (metal ion: zinc and ruthenium) is described. The synthesis and characterization of these complexes are presented. In case of the zinc complex, the obtained product is an aggregate, while only the monomer is obtained in the case of the ruthenium derivative. Both complexes could be attached onto the TiO 2 surface by using the reported method. Both dyes are expected to form monolayers with dye molecules standing on the surface of nano-structured TiO 2, forming higher-order aggregates with the zinc but not with the ruthenium complex. A highest monochromatic incident photo-to-current conversion efficiency (IPCE) of 1.6% at 690 nm was obtained for a solar cell based on the Pc-Zn sensitized nano-structured TiO 2 electrode, while an IPCE of 23% at 630 nm was obtained for the Pc-Ru sensitized electrode. Overall conversion efficiencies (η) at a simulated AM 1.5 (100 W.m-2) of 0.03% and 0.40% for the zinc and ruthenium complexes were achieved, respectively. The difference in efficiencies could be due to the formation of face-to-face aggregation in the former case. This work shows that the ruthenium complex, with two axial methylpyridine ligands, does not form aggregates in solution nor on the surface of TiO 2, making it possible for further construction of supramolecular systems with such types of phthalocyanine.

Electrochemical sensors based on functionalized ormosil-modified electrodes—role of ruthenium and palladium on the electrocatalysis of NADH and ascorbic acid

We report here in the preparation of seven different types of functionalized ormosil-modified electrodes derived from 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane in acidic medium in the presence of: (1) tris(2,2′-bipyridyl)ruthenium chloride; (2) palladium chloride; (3) both tris(2,2′-bipyridyl)ruthenium chloride and palladium chloride; (4) ferrocene monocarboxylic acid; (5) tris(2,2′-bipyridyl)ruthenium chloride and ferrocene Monocarboxylic acid; (6) palladium chloride and ferrocene monocarboxylic acid; (7) tris(2,2′-bipyridyl)ruthenium chloride, palladium chloride and ferrocene monocarboxylic. The electrocatalytic oxidation of reduced nicotinamide adenine dinuleotide (NADH) and ascorbic acid is examined on the surface of these functionalized ormosil-modified electrodes. The results based on cyclic voltammetry and amperometric measurements are reported. The results suggest: (a) excellent reversible redox electrochemistry of ferrocene monocarboxylic acid, when ruthenium and palladium both are incorporated within ormosil, as compared to that of redox electrochemistry of ferrocene monocarboxylic acid observed in homogeneous solution; (b) the presence of ruthenium facilitate the electrocatalytic efficiency of ormosil-modified electrode; (c) relatively, better selective oxidation of NADH on the surface of functionalized ormosil-modified electrode made in the presence of both palladium and ruthenium derivatives. The performances of these modified electrodes are reported in this communication.

A new class of tethered-arene ruthenium(II) complexes with pendant P and C donor atoms: synthesis of eta6:eta1:eta1 phosphonio-azabutadienyl ruthenabicycles via allenylidene intermediates.

The activation of 1,1-diphenyl-2-propyn-1-ol by complexes [RuCl(eta(6)-p-cymene)[eta(2)-P,N-Ph(2)PCH(2)P([=NR)Ph(2)]](+) results in the formation of the unusual tethered (eta(6)-arene)-ruthenium(ii) derivatives, via an unprecedented iminophosphorane-allenylidene coupling process.

Ruthenium Derivatives of NiS2N2 Complexes as Analogues of Bioorganometallic Reaction Centers.

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionRuthenium Derivatives of NiS2N2 Complexes as Analogues of Bioorganometallic Reaction Centers.M. A. Reynolds, T. B. Rauchfuss, and S. R. WilsonCite this: Organometallics 2003, 22, 22, 4620Publication Date (Web):September 24, 2003Publication History Published online24 September 2003Published inissue 1 October 2003https://doi.org/10.1021/om0340544Copyright © 2003 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views231Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (8 KB) Get e-Alerts Get e-Alerts

Reduction of the NO + ligand in ‘half-sandwich’ ruthenium derivatives

The reduction of the tetrafluoroborate salts of the ruthenium nitrosyl dicationic [Ru(η 5-C 5R 5)(NO)(L) 2] 2+ (R=Me, L=PMe 3, 1a; PMe 2Ph, 1b; R=H, L=PPh 3, 2d) and monocationic complexes [Ru(Me)Cp*(NO)L] + (L=PMe 3, 3a; PMe 2Ph, 3b) (Cp*=η 5-C 5Me 5) has been studied by electrochemical and spectroscopic (IR, NMR, EPR) techniques. The nitrosyl complexes 1a, 1b and 2d exhibit two successive one-electron cathodic processes due to the sequential reduction of coordinated NO + to NO and NO −, respectively. Chemical reduction yields products of rearrangement of the intermediates which have been spectroscopically characterized. EPR studies and theoretical calculations show that in the first one-electron reduction product the electron interacts with the NO nitrogen atom and that the RuNO moiety presents significant distortion from linearity. The X-ray structure of the related [Ir(Me) 2Cp*(NO)]BF 4 has been determined.

Ruthenium Derivatives of NiS2N2Complexes as Analogues of Bioorganometallic Reaction Centers

Recent results from structural biology demonstrate the catalytic significance of Ni(SR)2L2 centers attached to a second metal that binds CO, in particular the NiFe hydrogenases and acetyl CoA synthase. In experiments aimed at developing bimetallic derivatives exhibiting an affinity for CO, we have studied Ru(II) derivatives of nickel diaminodithiolates and the reactivity of these complexes toward CO and other small molecules. The reaction of [Cp*Ru(NCMe)3]OTf and NiS2N2 (S2N2 = N,N‘-bis(2-mercaptoethyl)-N,N‘-dimethyl-1,3-diaminoethane) gives [Cp*Ru(NiS2N2)]2(OTf)2 ([1]2(OTf)2), which exists as a monomer−dimer equilibrium in MeCN solution. Crystallographic analysis of [1]2(OTf)2 reveals a centrosymmetric dication with the Ru being quasi-octahedral and the NiS2N2 coordination sphere being relatively planar, the metal centers being linked via pairs of μ2-SR and μ3-SR units. Complex [1]22+ oxygenates and sulfidizes with O2 and S8, respectively, to give [Cp*Ru(NiS2N2)(η2-E2)]+ (E = O, S), which were characteri...

Oxidation of dibenzothiophene by hydrogen peroxide or monopersulfate and metal–sulfophthalocyanine catalysts: an easy access to biphenylsultone or 2-(2′-hydroxybiphenyl)sulfonate under mild conditions

A catalytic system consisting of metal–sulfophthalocyanines (MPcS) and monopersulfate or hydrogen peroxide as oxidants was effective in the dibenzothiophene oxidative desulfurization with various yields and selectivities. Oxidations were conducted at room temperature in acetonitrile–water mixed solvent. The dibenzothiophene oxidation involved the step by step formation of dibenzothiophene dioxide and biphenylsultone (dibenzo-1,2-oxathiine 2,2-dioxide), followed by hydrolysis to 2(2′-hydroxybiphenyl)sulfonate and finally catalytic desulfurization to 2-hydroxybiphenyl (2-phenylphenol) and sulfuric acid; all the intermediate compounds were identified. Moreover, catalytic over-oxidation of 2-hydroxybiphenyl, with ring fission and formation of various oxidation products, among them carbon dioxide, oxalic and benzoic acid, was also observed. Among the various MPcS catalysts examined (M = Fe, Co and Ru), the ruthenium derivative exhibited the best performances with persulfate and iron derivative with hydrogen peroxide; in both cases the slow step of the process consisted in the oxidation of dibenzothiophene dioxide to biphenylsultone.

C−N and C−C Coupling Reactions: Preparation of New N-Heterocyclic Ruthenium Derivatives

Three novel types of complexes containing heterocyclic ligands are prepared by condensation of the allenylidene ligand of [Ru(η5-C5H5)(CCCPh2)(CO)(PiPr3)]BF4 (1) with propargylamines. Complex 1 reacts with propargylamine to give initially [Ru(η5-C5H5){C(CHCPh2)NHCH2C⋮CH}(CO)(PiPr3)]BF4 (2). Treatment of 2 with KOH in methanol affords the bicyclic derivative Ru(η5-C5H5){4-methylidene-6,6-diphenyl-2-azabicyclo[3.1.0]hex-2-en-1-yl}(CO)(PiPr3) (3). The formation of 3 takes place via the intermediate Ru(η5-C5H5){C(CHCPh2)NCH2C⋮CH}(CO)(PiPr3) (4), which is isolated when the deprotonation of 2 is carried out in tetrahydrofuran as solvent. In contrast to propargylamine, the addition of 1,1-diethylpropargylamine to 1 leads to the dihydropyridiniumyl derivative [Ru(η5-C5H5){2,2-diethyl-5-diphenylidene-2,5-dihydropyridinium-6-yl)(CO)(PiPr3)]BF4 (5) in a one-pot synthesis. Complex 1 also reacts with N-methylpropargylamine. The reaction affords [Ru(η5-C5H5){C(CHCPh2)N(CH3)CH2C⋮CH}(CO)(PiPr3)]BF4 (6). Treatment of 6 with sodium methoxide, at −78 °C, gives a 1:1 mixture of the dihydronaphthopyrrolyl diastereomers (RRuSC,SRuRC)-[Ru(η5-C5H5){9-phenyl-4,4a-dihydronaphtho[2,3-c]-1-pyrrolyl})(CO)(PiPr3) (7a) and (RRuRC,SRuSC)-[Ru(η5-C5H5){9-phenyl-4,4a-dihydronaphtho[2,3-c]-1-pyrrolyl})(CO)(PiPr3) (7b). Complexes 3 and 5 and the enantiomeric mixture 7a have been characterized by X-ray diffraction analysis.