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1.
We demonstrate that RuII(CO)2–protein complexes, formed by the reaction of the hydrolytic decomposition products of [fac‐RuCl(κ2‐H2NCH2CO2)(CO)3] (CORM‐3) with histidine residues exposed on the surface of proteins, spontaneously release CO in aqueous solution, cells, and mice. CO release was detected by mass spectrometry (MS) and confocal microscopy using a CO‐responsive turn‐on fluorescent probe. These findings support our hypothesis that plasma proteins act as CO carriers after in vivo administration of CORM‐3. CO released from a synthetic bovine serum albumin (BSA)–RuII(CO)2 complex leads to downregulation of the cytokines interleukin (IL)‐6, IL‐10, and tumor necrosis factor (TNF)‐α in cancer cells. Finally, administration of BSA–RuII(CO)2 in mice bearing a colon carcinoma tumor results in enhanced CO accumulation at the tumor. Our data suggest the use of RuII(CO)2–protein complexes as viable alternatives for the safe and spatially controlled delivery of therapeutic CO in vivo.  相似文献   

2.
The complete sequence of reactions in the base‐promoted reduction of [{RuII(CO)3Cl2}2] to [RuI2(CO)4]2+ has been unraveled. Several μ‐OH, μ:κ2‐CO2H‐bridged diruthenium(II) complexes have been synthesized; they are the direct results of the nucleophilic activation of metal‐coordinated carbonyls by hydroxides. The isolated compounds are [Ru2(CO)4(μ:κ2C,O‐CO2H)2(μ‐OH)(NPF‐Am)2][PF6] ( 1 ; NPF‐Am=2‐amino‐5,7‐trifluoromethyl‐1,8‐naphthyridine) and [Ru2(CO)4(μ:κ2C,O‐CO2H)(μ‐OH)(NP‐Me2)2][BF4]2 ( 2 ), secured by the applications of naphthyridine derivatives. In the absence of any capping ligand, a tetranuclear complex [Ru4(CO)8(H2O)23‐OH)2(μ:κ2C,O‐CO2H)4][CF3SO3]2 ( 3 ) is isolated. The bridging hydroxido ligand in 1 is readily replaced by a π‐donor chlorido ligand, which results in [Ru2(CO)4(μ:κ2C,O‐CO2H)2(μ‐Cl)(NP‐PhOMe)2][BF4] ( 4 ). The production of [Ru2(CO)4]2+ has been attributed to the thermally induced decarboxylation of a bis(hydroxycarbonyl)–diruthenium(II) complex to a dihydrido–diruthenium(II) species, followed by dinuclear reductive elimination of molecular hydrogen with the concomitant formation of the RuI? RuI single bond. This work was originally instituted to find a reliable synthetic protocol for the [Ru2(CO)4(CH3CN)6]2+ precursor. It is herein prescribed that at least four equivalents of base, complete removal of chlorido ligands by TlI salts, and heating at reflux in acetonitrile for a period of four hours are the conditions for the optimal conversion. Premature quenching of the reaction resulted in the isolation of a trinuclear RuI2RuII complex [{Ru(NP‐Am)2(CO)}{Ru2(NP‐Am)2(CO)2(μ‐CO)2}(μ33C,O,O′‐CO2)][BF4]2 ( 6 ). These unprecedented diruthenium compounds are the dinuclear congeners of the water–gas shift (WGS) intermediates. The possibility of a dinuclear pathway eliminates the inherent contradiction of pH demands in the WGS catalytic cycle in an alkaline medium. A cooperative binuclear elimination could be a viable route for hydrogen production in WGS chemistry.  相似文献   

3.
A series of RuII polypyridyl complexes of the structural design [RuII(R?tpy)(NN)(CH3CN)]2+ (R?tpy=2,2′:6′,2′′‐terpyridine (R=H) or 4,4′,4′′‐tri‐tert‐butyl‐2,2′:6′,2′′‐terpyridine (R=tBu); NN=2,2′‐bipyridine with methyl substituents in various positions) have been synthesized and analyzed for their ability to function as electrocatalysts for the reduction of CO2 to CO. Detailed electrochemical analyses establish how substitutions at different ring positions of the bipyridine and terpyridine ligands can have profound electronic and, even more importantly, steric effects that determine the complexes’ reactivities. Whereas electron‐donating groups para to the heteroatoms exhibit the expected electronic effect, with an increase in turnover frequencies at increased overpotential, the introduction of a methyl group at the ortho position of NN imposes drastic steric effects. Two complexes, [RuII(tpy)(6‐mbpy)(CH3CN)]2+ (trans‐[ 3 ]2+; 6‐mbpy=6‐methyl‐2,2′‐bipyridine) and [RuII(tBu?tpy)(6‐mbpy)(CH3CN)]2+ (trans‐[ 4 ]2+), in which the methyl group of the 6‐mbpy ligand is trans to the CH3CN ligand, show electrocatalytic CO2 reduction at a previously unreactive oxidation state of the complex. This low overpotential pathway follows an ECE mechanism (electron transfer–chemical reaction–electron transfer), and is a direct result of steric interactions that facilitate CH3CN ligand dissociation, CO2 coordination, and ultimately catalytic turnover at the first reduction potential of the complexes. All experimental observations are rigorously corroborated by DFT calculations.  相似文献   

4.
The clectrochemical behaviour of the complexes [RuII(L)(CO)2Cl2], [RuII(L)(CO)Cl3][Me4N] and [RuII(L)(CO)2(CH3CN)2][CF3SO3]2 (L = 2,2′-bipyridine or 4,4′-isopropoxycarbonyl-2,2′-bipyridine) has been investigated in CH3CN. The oxidation of [Ru(L)(CO)2Cl2] produces new complexes [RuIII(L)(CO)(CH3CN)2Cl]2+ as a consequence of the instability of the electrogenerated transient RuIII species [RuIII(L)(CO)2Cl2]+. In contrast, the oxidation of [RuII(L)(CO)Cl3][Me4N] produces the stable [RuIII(L)(CO)Cl3] complex. In contrast [RuII(L)(CO)2(CH3CN)2][CF3SO3]2 is not oxidized in the range up to the most positive potentials achievable. The reduction of [RuII(L)(CO)2Cl2] and [RuII(L)(CO)2(CH3CN)2][CF3SO3]2 results in the formation of identical dark blue strongly adherent electroactive films. These films exhibit the characteristics of a metal-metal bond dimer structure. No films are obtained on reduction of [RuII(L)(CO)Cl3][Me4N]. The effect of the substitution of the bipyridine ligand by electron-withdrawing carboxy ester groups on the electrochemical behaviour of all these complexes has also been investigated.  相似文献   

5.
We have designed and synthesised a [Ru(CO)3Cl2(NAC)] pro‐drug that features an N‐acetyl cysteine (NAC) ligand. This NAC carbon monoxide releasing molecule (CORM) conjugate is able to simultaneously release biologically active CO and to ablate the concurrent formation of reactive oxygen species (ROS). Complexes of the general formulae [Ru(CO)3(L)3]2+, including [Ru(CO)3Cl(glycinate)] (CORM‐3), have been shown to produce ROS through a water–gas shift reaction, which contributes significantly, for example, to their antibacterial activity. In contrast, NAC‐CORM conjugates do not produce ROS or possess antibacterial activity. In addition, we demonstrate the synergistic effect of CO and NAC both for the inhibition of nitric oxide (formation) and in the expression of tumour‐necrosis factor (TNF)‐α. This work highlights the advantages of combining a CO‐releasing scaffold with the anti‐oxidant and anti‐inflammatory drug NAC in a unique pro‐drug.  相似文献   

6.
Abstract

The triply halide-bridged binuclear complexes [Ru2Cl5(CO)(AsPh3)3] (AsPh3 = triphenylarsine), [Ru2Cl5(CO)(PPh3)2(AsPh3)] (PPh3 = triphenylphosphine), [Ru2Cl5(CO)(AsPh3)2(PPh3)], [Ru2 Br5(CO)(PPh3)3], [Ru2Cl5(CO)(P{p-tol}3)2(PPh3)] (P{p-tol}3 = tri-p-tolylphosphine) and [Ru2 Br2Cl3(PPh3)2(AsPh3)] were prepared from the precursor compounds ttt-[RuX2(CO)2(P)2] (X = Cl or Br) and [RuY3(P')2S]·S (Y = Cl or Br; P=PPh3, AsPh3 or P{p- tol}3 and P' = AsPh3 or PPh3; S=DMA or MeOH, where DMA = N,N'-dimethylacetamide). The molecular structures of the binuclear complexes [Ru2Cl5(CO)(AsPh3)3] (P21/c), [Ru2Br5(CO)(PPh3)3] (P21/c) and ttt-[RuCl2(CO)2(PPh3)2] (P1) were determined by X-ray diffraction methods. The complexes are always formed by two Ru atoms bridged through three halide anions, two of which are × type (from the RuII precursor) and the other is Y type (from the rutheniumIII precursor) confirming our previously suggested mechanism for obtaining this class of complexes. The RuII atom is also coordinated to a carbon monoxide molecule and two P ligands from the ttt-starting isomer whereas the RuIII atom is bonded to two non-bridging Y halides and one P' molecule. The presence of RuIII was confirmed by EPR data, a technique that was also useful to suggest the symmetry of the complexes. The absence of intervalence charge-transfer transitions (IT) in the near infrared spectrum confirms that the binuclear complexes have localized valence. The IR spectra of the complexes show; (CO) bands close to 1970 cm?1 and ν(Ru-Cl) or(Ru-Br) bands at about 230–380 cm?1 corresponding to halides at terminal or bridged positions. Two widely separated redox processes, RuII/RuII←RuII/RuIII→RuIII/RuIII, were observed by cyclic voltammetry and differential pulse voltammetry.  相似文献   

7.
The basic aqueous coordination chemistry of RuII has been studied using the catalytically important TPPTS phosphine (TPPTS=trisodium salt of 3,3′,3″‐phosphinetriylbenzenesulfonic acid) and small gas molecules (H2, CO, N2) as ligands. As a result, new water‐soluble ruthenium mixed hydride complexes, presumably key species in many industrial catalytic processes, have been formed and identified. The RuII mixed hydrides were synthesized, and their formation was followed in situ by multinuclear NMR spectroscopy, pressurizing aqueous RuII? TPPTS systems with H2 and CO gas in sapphire NMR tubes. The formation equilibrium of these complexes is highly dependant on the temperature and the gas pressures. Under 50 atm of N2, the unique [RuH(CO)(N2)(TPPTS)2(H2O)]+ complex has been identified, which could be the first step toward dinitrogen activation.  相似文献   

8.
We used density functional theory to investigate the capacity for carbon monoxide (CO) release of five newly synthesized manganese‐containing CO‐releasing molecules (CO‐RMs), namely CORM‐368 ( 1 ), CORM‐401 ( 2 ), CORM‐371 ( 3 ), CORM‐409 ( 4 ), and CORM‐313 ( 5 ). The results correctly discriminated good CO releasers ( 1 and 2 ) from a compound unable to release CO ( 5 ). The predicted Mn? CO bond dissociation energies were well correlated (R2≈0.9) with myoglobin (Mb) assay experiments, which quantified the formation of MbCO, and thus the amount of CO released by the CO‐RMs. The nature of the Mn? CO bond was characterized by natural bond orbital (NBO) analysis. This allowed us to identify the key donor–acceptor interactions in the CO‐RMs, and to evaluate the Mn? CO bond stabilization energies. According to the NBO calculations, the charge transfer is the major source of Mn? CO bond stabilization for this series. On the basis of the nature of the experimental buffers, we then analyzed the nucleophilic attack of putative ligands (L′=HPO42?, H2PO4?, H2O, and Cl?) at the metal vacant site through the ligand‐exchange reaction energies. The analysis revealed that different L′‐exchange reactions were spontaneous in all the CO‐RMs. Finally, the calculated second dissociation energies could explain the stoichiometry obtained with the Mb assay experiments.  相似文献   

9.
Hereby we present the synthesis of several ruthenium(II) and ruthenium(III) dithiocarbamato complexes. Proceeding from the Na[trans‐RuIII(dmso)2Cl4] ( 2 ) and cis‐[RuII(dmso)4Cl2] ( 3 ) precursors, the diamagnetic, mixed‐ligand [RuIIL2(dmso)2] complexes 4 and 5 , the paramagnetic, neutral [RuIIIL3] monomers 6 and 7 , the antiferromagnetically coupled ionic α‐[RuIII2L5]Cl complexes 8 and 9 as well as the β‐[RuIII2L5]Cl dinuclear species 10 and 11 (L=dimethyl‐ (DMDT) and pyrrolidinedithiocarbamate (PDT)) were obtained. All the compounds were fully characterised by elemental analysis as well as 1H NMR and FTIR spectroscopy. Moreover, for the first time the crystal structures of the dinuclear β‐[RuIII2(dmdt)5]BF4 ? CHCl3 ? CH3CN and of the novel [RuIIL2(dmso)2] complexes were also determined and discussed. For both the mono‐ and dinuclear RuII and RuIII complexes the central metal atoms assume a distorted octahedral geometry. Furthermore, in vitro cytotoxicity of the complexes has been evaluated on non‐small‐cell lung cancer (NSCLC) NCI‐H1975 cells. All the mono‐ and dinuclear RuIII dithiocarbamato compounds (i.e., complexes 6 – 10 ) show interesting cytotoxic activity, up to one order of magnitude higher with respect to cisplatin. Otherwise, no significant antiproliferative effect for either the precursors 2 and 3 or the RuII complexes 4 and 5 has been observed.  相似文献   

10.
The complex cis‐[RuIII(dmbpy)2Cl2](PF6) ( 2 ) (dmbpy = 4, 4′‐dimethyl‐2, 2′‐bipyridine) was obtained from the reaction of cis‐[RuII(dmbpy)2Cl2] ( 1 ) with ammonium cerium(IV) nitrate followed by precipitation with saturated ammonium hexafluoridophosphate. The 1H NMR spectrum of the RuIII complex confirms the presence of paramagnetic metal atoms, whereas that of the RuII complex displays diamagnetism. The 31P NMR spectrum of the RuIII complex shows one signal for the phosphorus atom of the PF6 ion. The perspective view of each [RuII/III(dmbpy)2Cl2]0/+ unit manifests that the ruthenium atom is in hexacoordinate arrangement with two dmbpy ligands and two chlorido ligands in cis position. As the oxidation state of the central ruthenium metal atom becomes higher, the average Ru–Cl bond length decreases whereas the Ru–N (dmbpy) bond length increases. The cis‐positioned dichloro angle in RuIII is 1.3° wider than that in the RuII. The dihedral angles between pair of planar six‐membered pyridyl ring in the dmbpy ligand for the RuII are 4.7(5)° and 5.7(4)°. The observed inter‐planar angle between two dmbpy ligands in the RuII is 89.08(15)°, whereas the value for the RuIII is 85.46(20)°.  相似文献   

11.
Presented herein is a set of bimetallic and trimetallic “coordination booster‐catalyst” assemblies in which the coordination complexes [RuII(terpy)2] and [OsII(terpy)2] acted as boosters for enhancement of the catalytic activity of [RuII(NHC)(para‐cymene)]‐based catalytic site. The boosters accelerated the oxidative loss of para‐cymene from the catalytic site to generate the active catalyst during the oxidation of alkenes and alkynes into corresponding aldehydes, ketones and diketones. It was found that the boosting efficiency of the [OsII(terpy)2] units was considerably higher than its congener [RuII(terpy)2] unit in these assemblies. Mechanistic studies were conducted to understand this unique improvement.  相似文献   

12.
Alcohols are oxidized by N‐methylmorpholine‐N‐oxide (NMO), ButOOH and H2O2 to the corresponding aldehydes or ketones in the presence of catalyst, [RuH(CO)(PPh3)2(SRaaiNR′)]PF6 ( 2 ) and [RuCl(CO)(PPh3)(SκRaaiNR′)]PF6 ( 3 ) (SRaaiNR′ ( 1 ) = 1‐alkyl‐2‐{(o‐thioalkyl)phenylazo}imidazole, a bidentate N(imidazolyl) (N), N(azo) (N′) chelator and SκRaaiNR′ is a tridentate N(imidazolyl) (N), N(azo) (N′), Sκ‐R is tridentate chelator; R and R′ are Me and Et). The single‐crystal X‐ray structures of [RuH(CO)(PPh3)2(SMeaaiNMe)]PF6 ( 2a ) (SMeaaiNMe = 1‐methyl‐2‐{(o‐thioethyl)phenylazo}imidazole) and [RuH(CO)(PPh3)2(SEtaaiNEt)]PF6 ( 2b ) (SEtaaiNEt = 1‐ethyl‐2‐{(o‐thioethyl)phenylazo}imidazole) show bidentate N,N′ chelation, while in [RuCl(CO)(PPh3)(SκEtaaiNEt)]PF6 ( 3b ) the ligand SκEtaaiNEt serves as tridentate N,N′,S chelator. The cyclic voltammogram shows RuIII/RuII (~1.1 V) and RuIV/RuIII (~1.7 V) couples of the complexes 2 while RuIII/RuII (1.26 V) couple is observed only in 3 along with azo reductions in the potential window +2.0 to ?2.0 V. DFT computation has been used to explain the spectra and redox properties of the complexes. In the oxidation reaction NMO acts as best oxidant and [RuCl(CO)(PPh3)(SκRaaiNR′)](PF6) ( 3 ) is the best catalyst. The formation of high‐valent RuIV=O species as a catalytic intermediate is proposed for the oxidation process. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

13.
Direct use of low pressures of CO2 as a C1 source without concentration from gas mixtures is of great interest from an energy‐saving viewpoint. Porous heterogeneous catalysts containing both adsorption and catalytically active sites are promising candidates for such applications. Here, we report a porous coordination polymer (PCP)‐based catalyst, PCP‐RuII composite, bearing a RuII‐CO complex active for CO2 reduction. The PCP‐RuII composite showed improved CO2 adsorption behavior at ambient temperature. In the photochemical reduction of CO2 the PCP‐RuII composite produced CO, HCOOH, and H2. Catalytic activity was comparable with the corresponding homogeneous RuII catalyst and ranks among the highest of known PCP‐based catalysts. Furthermore, catalytic activity was maintained even under a 5 % CO2/Ar gas mixture, revealing a synergistic effect between the adsorption and catalytically active sites within the PCP‐RuII composite.  相似文献   

14.
Subtle ligand modifications on RuII-polypyridyl complexes may result in different excited-state characteristics, which provides the opportunity to tune their photo-physicochemical properties and subsequently change their biological functions. Here, a DNA-targeting RuII-polypyridyl complex (named Ru1 ) with highly photosensitizing 3IL (intraligand) excited state was designed based on a classical DNA-intercalator [Ru(bpy)2(dppz)] ⋅ 2 PF6 by incorporation of the dppz (dipyrido[3,2-a:2′,3′-c]phenazine) ligand tethered with a pyrenyl group, which has four orders of magnitude higher potency than the model complex [Ru(bpy)2(dppz)] ⋅ 2 PF6 upon light irradiation. This study provides a facile strategy for the design of organelle-targeting RuII-polypyridyl complexes with dramatically improved photobiological activity.  相似文献   

15.
A “metal–ketimine+ArI(OR)2” approach has been developed for preparing metal–ketimido complexes, and ketimido ligands are found to stabilize high‐valent metallophthalocyanine (M? Pc) complexes such as ruthenium(IV) phthalocyanines. Treatment of bis(ketimine) ruthenium(II) phthalocyanines [RuII(Pc)(HN?CPh2)2] ( 1a ) and [RuII(Pc)(HNQu)2] ( 1b ; HNQu=N‐phenyl‐1,4‐benzoquinonediimine) with PhI(OAc)2 affords bis(ketimido) ruthenium(IV) phthalocyanines [RuIV(Pc)(N?CPh2)2] ( 2a ) and [RuIV(Pc)(NQu)2] ( 2b ), respectively. X‐ray crystal structures of 1b and [RuII(Pc)(PhN?CHPh)2] ( 1c ) show Ru? N(ketimine) distances of 2.075(4) and 2.115(3) Å, respectively. Complexes 2a , 2b readily revert to 1a , 1b upon treatment with phenols. 1H NMR spectroscopy reveals that 2a , 2b are diamagnetic and 2b exists as two isomers, consistent with a proposed eclipsed orientation of the ketimido ligands in these ruthenium(IV) complexes. The reaction of 1a , 1b with PhI(OAc)2 to afford 2a , 2b suggests the utility of ArI(OR)2 as an oxidative deprotonation agent for the generation of high‐valent metal complexes featuring M? N bonds with multiple bonding characters. DFT and time‐dependent (TD)‐DFT calculations have been performed on the electronic structures and the UV/Vis absorption spectra of 1b and 2b , which provide support for the diamagnetic nature of 2b and reveal a significant barrier for rotation of the ketimido group about the Ru? N(ketimido) bond.  相似文献   

16.
CuII/RuII and CdII/RuII hybrid complexes [Cu(L1–3)(NC5H4C≡CRu(dppe)2Cl)] (1a-3a) and [Cd(L1-3)(NC5H4C≡CRu(dppe)2Cl)] (1b–3b) have been prepared by reaction of trans-[RuCl(dppe)2(C≡C-py-3)] (1) with copper or cadmium acetate in the presence of Schiff base ligands LH1–3 (where LH = 2-(pyrrole-2-yl-methylidine)aminophenol (LH1), 5-bromo-2-(pyrrole-2-yl-methylidine)aminophenol (LH2) and 5-nitro-2-(pyrrole-2-yl-methylidine)aminophenol (LH3)). The hybrid materials were characterized on the basis of elemental analyses, TEM, IR, UV–visible, 1H NMR, and 31P NMR spectral studies. TEM overview observations revealed well-dispersed spherical nanoparticles of ~60 nm are formed. Quasireversible redox behavior is observed for CuII/RuII complexes corresponding to CuI/CuII and RuII/RuIII couples. All the complexes exhibit blue-green emission as a result of fluorescence from the intraligand (π → π*) emission excited state with good quantum yield. The second-order nonlinear optical (NLO) properties of CuII/RuII and CdII/RuII complexes have been investigated by the Kurtz-powder method. The second harmonic generation efficiency of these complexes show that these complexes are NLO active and display good second-order nonlinear optical activity.  相似文献   

17.
RuII–bis‐pyridine complexes typically absorb below 450 nm in the UV spectrum and their molar extinction coefficients are only moderate (ε<16 000 M ?1 cm?1). Thus, RuII–polyimine complexes that show intense visible‐light absorptions are of great interest. However, no effective light‐harvesting ruthenium(II)/organic chromophore arrays have been reported. Herein, we report the first visible‐light‐harvesting RuII–coumarin arrays, which absorb at 475 nm (ε up to 63 300 M ?1 cm?1, 4‐fold higher than typical RuII–polyimine complexes). The donor excited state in these arrays is efficiently converted into an acceptor excited state (i.e., efficient energy‐transfer) without losses in the phosphorescence quantum yield of the acceptor. Based on steady‐state and time‐resolved spectroscopy and DFT calculations, we proposed a general rule for the design of RuII–polypyridine–chromophore light‐harvesting arrays, which states that the 1IL energy level of the ligand must be close to the respective energy level of the metal‐to‐ligand charge‐transfer (M LCT) states. Lower energy levels of 1IL/3IL than the corresponding 1M LCT/3M LCT states frustrate the cascade energy‐transfer process and, as a result, the harvested light energy cannot be efficiently transferred to the acceptor. We have also demonstrated that the light‐harvesting effect can be used to improve the upconversion quantum yield to 15.2 % (with 9,10‐diphenylanthracene as a triplet‐acceptor/annihilator), compared to the parent complex without the coumarin subunit, which showed an upconversion quantum yield of only 0.95 %.  相似文献   

18.
The ligand containing the 4‐amino‐1‐benzyl piperidine group, N, N′‐(4‐amino‐1‐benzyl piperidine)‐glyoxime, (LH2) (1) was prepared from 4‐amino‐1‐benzyl piperidine with anti‐dichloroglyoxime at ? 15 °C in absolute Tetrahydrofuran (THF). In the trinuclear [Pd(L)2Ru2(phen)4](ClO4)2 (4) and [Pd(L)2Ru2(bpy)4](ClO4)2 (5) metal complexes, the PdII ion centered into the main oxime core by the coordination of the imino groups while the two RuII ions coordinated dianionic oxygen donors of the oxime groups and linked to the ligands of 1,10‐phenanthroline and 2,2′‐bipyridine. The mono and trinuclear metal complexes were characterized by elemental analyses, FT‐IR, UV–vis, 1H and 13C‐NMR spectra, magnetic susceptibility measurements, molar conductivity, cyclic voltammetry, mass spectra, X‐ray powder techniques and their morphology by SEM measurements. The cyclic voltammetric results show that the cathodic peak (Epc) potential of (3) shifts towards more positive values compared with that of (2) as a result of the BPh2+‐bridged complex formation. The Suzuki–Miyaura reaction was used to investigate their activity as catalyst either prepared in‐situ or from well‐defined complexes. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

19.
Carbon monoxide (CO) has recently been shown to impart beneficial effects in mammalian physiology and considerable research attention is now being directed toward metal–carbonyl complexes as a means of delivering CO to biological targets. Two ruthenium carbonyl complexes, namely trans‐dicarbonyldichlorido(4,5‐diazafluoren‐9‐one‐κ2N,N′)ruthenium(II), [RuCl2(C11H6N2O)(CO)2], (1), and fac‐tricarbonyldichlorido(4,5‐diazafluoren‐9‐one‐κN)ruthenium(II), [RuCl2(C11H6N2O)(CO)3], (2), have been isolated and structurally characterized. In the case of complex (1), the trans‐directing effect of the CO ligands allows bidentate coordination of the 4,5‐diazafluoren‐9‐one (dafo) ligand despite a larger bite distance between the N‐donor atoms. In complex (2), the cis disposition of two chloride ligands restricts the ability of the dafo molecule to bind ruthenium in a bidentate fashion. Both complexes exhibit well defined 1H NMR spectra confirming the diamagnetic ground state of RuII and display a strong absorption band around 300 nm in the UV.  相似文献   

20.
Treatment of Ru3(CO)12 with an equivalent of (2‐phenyl‐1H ‐inden‐3‐yl)dicyclohexylphosphine ( 1 ) and (2‐pyridyl‐1H ‐inden‐1‐yl)dicyclohexylphosphine ( 4 ) in refluxing heptane gave the novel trinuclear ruthenium clusters (μ3‐η125–2‐phenyl‐3‐Cy2PC9H4)Ru3(CO)8 ( 1c ) and [μ2‐η1–2‐(pyridin‐2‐yl)‐3‐Cy2PC9H6]Ru3(CO)9 ( 4a ), respectively, via C ─ H bond cleavage. (2‐Mesityl‐1H ‐inden‐3‐yl)dicyclohexylphosphine ( 2 ) reacted with Ru3(CO)12 in refluxing heptane to give the trinuclear ruthenium cluster [μ‐2‐mesityl‐(3‐Cy2PC9H5)](μ2‐CO)Ru3(CO)9 ( 2c ) via C ─ H bond cleavage and carbonyl insertion. 2‐(Anthracen‐9‐yl)‐1H –inden‐3‐yldicyclohexylphosphine ( 3 ) reacted with Ru3(CO)12 in refluxing heptane to give the dinuclear ruthenium cluster [μ2‐η33–2‐(anthracen‐9‐yl)‐3‐Cy2PC9H6]Ru2(CO)5 ( 3a ). The structures of 1c , 2c , 3a and 4a were fully characterized using IR and NMR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. These results suggest that the 2‐aryl substituent on the indenyl ring has a pronounced effect on the reaction and coordination modes of Ru3(CO)12.  相似文献   

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