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1.
Reaction of [(η5-Cp)Ru(PPh3)2Cl] (1) with excess para-amino-N-(pyrid-2-ylmethylene)-phenylamine ligand (app) in methanol in the presence of NH4BF4 leads to the formation of [η5-CpRu(PPh3)(aap)]BF4 (6BF4). Similarly, [(η5-ind)Ru(PPh3)2(CH3CN)]BF4 (4BF4) and [(η5-Cp*)Ru(PPh3)2(CH3CN)]BF4 (5BF4) react with app to yield the cationic complexes [(η5-ind)Ru(PPh3)(app)]BF4 (7BF4) and [(η5-Cp*)Ru(PPh3)(app)]BF4 (8BF4), respectively. The complexes were characterized by analysis and spectroscopic data. The structure of a representative complex (6BF4) was established by single-crystal X-ray methods.  相似文献   

2.
A series of dinuclear half-sandwich Ru(II), Os(II) and Ir(III) complexes [Ru2(μ-Ln)(η6-pcym)2Cl2](PF6)2 ( 1 , 4 ), [Os2(μ-Ln)(η6-pcym)2Cl2](PF6)2 ( 2 , 5 ) and [Ir2(μ-Ln)(η5-Cp*)2Cl2](PF6)2 ( 3 , 6 ), based on 4,4′-biphenyl-based bridging Schiff base ligands N,N′-(biphenyl-4,4′-diyldimethylidyne)bis-2-(pyridin-2-yl)methanamine (L1; for 1 – 3 ) and N,N′-(biphenyl-4,4′-diyldimethylidyne)bis-2-(pyridin-2-yl)ethanamine (L2; for 4 – 6 ) is reported; pcym = 1-methyl-4-(propan-2-yl)benzene, Cp* = pentamethylcyclopentadienyl. The complexes were characterized by relevant analytical techniques (i.e. elemental analysis, FT-IR, NMR, ESI-MS), and their in vitro cytotoxicity was assessed at six cancerous and two non-cancerous (healthy) human cell lines. Overall, complexes 4 – 6 , containing the L2 bridging ligand, revealed higher cytotoxicity as compared with 1 – 3 and, thus, they were studied in greater detail. The best-performing complex 6 exceeded at least twice the in vitro cytotoxicity of cisplatin and showed high selectivity towards the cancer cells over the normal ones, including the primary culture of human hepatocytes. In contrast to cisplatin, complexes 4 – 6 did not induce the cell cycle modification of the treated A2780 human ovarian carcinoma cells (studied by flow cytometry and Western blot analysis). High levels of superoxide anion were induced by complexes 4 – 6 at the A2780 cells. The levels of activated forms of Caspase-3 and Caspase-8 at the A2780 cells treated by Ru(II) complex 4 were comparable with cisplatin, while complexes 5 and 6 had only a minor effect on activation of these caspases.  相似文献   

3.
Phosphine-pyrazolyl based tripod ligands ROCH2C(CH2Pz)2(CH2PPh2) (R = H, Me, allyl; Pz = pyrazol-1-yl) were efficiently synthesized and characterized. Reactions of these ligands with [Ru(η6-p-cymene)Cl2]2 afforded complexes of the type [Ru(η6-p-cymene)Cl2](L) (6-8) in which the ligands exhibit κ1-P-coordination to the metal center. Complex [Ru(η6-p-cymene)Cl2{Ph2PCH2C(CH2OH)(CH2Pz)2}] (6) underwent chloride-dissociation in CH2Cl2/MeCN to give complex [RuCl(η6-p-cymene){κ2(P,N)-Ph2PCH2C(CH2OH)(CH2Pz)2}][Cl] (9). Complexes 6-9 demonstrated poor to moderate catalytic activity in the transfer hydrogenation of acetophenone. All these complexes were fully characterized by analytical and spectroscopic methods and their molecular structures were determined by X-ray crystallographic study.  相似文献   

4.
A series of arene-ruthenium complexes of the general formula [RuCl26-C6H5(CH2)2R}L] with R=OH, CH2OH, OC(O)Fc, CH2OC(O)Fc (Fc=ferrocenyl) and L=PPh3, (diphenylphosphino)ferrocene, or bridging 1,1-bis(diphenylphosphino)ferrocene, have been synthesized. Two synthetic pathways have been used for these ferrocene-modified arene-ruthenium complexes: (a) esterification of ferrocene carboxylic acid with 2-(cyclohexa-1,4-dienyl)ethanol, followed by condensation with RuCl3 · nH2O to afford [RuCl26-C6H5(CH2)2OC(O)Fc}]2, and (b) esterification between ferrocene carboxylic acid and [RuCl26-C6H5(CH2)3OH}L] to give [RuCl26-C6H5(CH2)3OC(O)Fc}L]. All new compounds have been characterized by NMR and IR spectroscopy as well as by mass spectrometry. The single-crystal X-ray structure analysis of [RuCl26-C6H5(CH2)3OH}(PPh3)] shows that the presence of a CH2CH2CH2OH side-arm allows [RuCl26-C6H5(CH2)3OH}(PPh3)] to form an intramolecular hydrogen bond with a chlorine atom. The electrochemical behavior of selected representative compounds has been studied. Complexes with ferrocenylated side arms display the expected cyclic voltammograms, two independent reversible one-electron waves of the Ru(II)/Ru(III) and Fe(II)/Fe(III) redox couples. Introduction of a ferrocenylphosphine onto the ruthenium is reflected by an additonal reversible, one-electron wave due to ferrocene/ferrocenium system which is, however, coupled with the Ru(II)/Ru(III) redox system.  相似文献   

5.
The reactions of [(ind)Ru(PPh3)2CN] (ind = η5-C9H7) (1) and [CpRu(PPh3)2CN] (Cp = η5-C5H5) (2) with [(η6-p-cymene)Ru(bipy)Cl]Cl (bipy = 2,2′-bipyridine) (3) in the presence of AgNO3/NH4BF4 in methanol, respectively, yielded dicationic cyano-bridged complexes of the type [(ind)(PPh3)2Ru(μ-CN)Ru(bipy)(η6-p-cymene)](BF4)2 (4) and [Cp(PPh3)2Ru(μ-CN)Ru(bipy)(η6-p-cymene)](BF4)2 (5). The reaction of [CpRu(PPh3)2CN] (2), [CpOs(PPh3)2CN] (6) and [CpRu(dppe)CN] (7) with the corresponding halide complexes and [(η6-p-cymene)RuCl2]2 formed the monocationic cyano-bridge complexes [Cp(PPh3)2Ru(μ-CN)Os(PPh3)2Cp](BF4) (8), [Cp(PPh3)2Os(μ- CN)Ru(PPh3)2Cp](BF4) (9) and [Cp(dppe)Ru(μ-CN)Os(PPh3)2Cp](BF4) (10) along with the neutral complexes [Cp(PPh3)2Ru(μ-CN)Ru (η6-p-cymene)Cl2] (11), [Cp(PPh3)2Os(μ-CN)Ru(η6-p-cymene)Cl2] (12), and [Cp(dppe) Ru(μ-CN)Ru(η6-p-cymene)Cl2] (13). These complexes were characterized by FT IR, 1H NMR, 31P{1H} NMR spectroscopy and the molecular structures of complexes 4, 8 and 11 were solved by X-ray diffraction studies.  相似文献   

6.
The new cationic mononuclear complexes [(η6-arene)Ru(Ph-BIAN)Cl]BF46-arene = benzene (1), p-cymene (2)], [(η5-C5H5)Ru(Ph-BIAN)PPh3]BF4 (3) and [(η5-C5Me5)M(Ph-BIAN)Cl]BF4 [M = Rh (4), Ir (5)] incorporating 1,2-bis(phenylimino)acenaphthene (Ph-BIAN) are reported. The complexes have been fully characterized by analytical and spectral (IR, NMR, FAB-MS, electronic and emission) studies. The molecular structure of the representative iridium complex [(η5-C5Me5)Ir(Ph-BIAN)Cl]BF4 has been determined crystallographically. Complexes 15 effectively catalyze the reduction of terephthaldehyde in the presence of HCOOH/CH3COONa in water under aerobic conditions and, among these complexes the rhodium complex [(η5-C5Me5)Rh(Ph-BIAN)Cl]BF4 (4) displays the most effective catalytic activity.  相似文献   

7.
Treatment of [Ru(PPh3)3Cl2] with one equivalent of tridentate Schiff base 2-[(2-dimethylamino-ethylimino)-methyl]-phenol (HL) in the presence of triethylamine afforded a ruthenium(III) complex [RuCl3(κ2-N,N-NH2CH2CH2NMe2)(PPh3)] as a result of decomposition of HL. Interaction of HL and one equivalent of [RuHCl(CO)(PPh3)3], [Ru(CO)2Cl2] or [Ru(tht)4Cl2] (tht = tetrahydrothiophene) under different conditions led to isolation of the corresponding ruthenium(II) complexes [RuCl(κ3-N,N,O-L)(CO)(PPh3)] (2), [RuCl(κ3-N,N,O-L)(CO)2] (3), and a ruthenium(III) complex [RuCl2(κ3-N,N,O-L)(tht)] (4), respectively. Molecular structures of 1·CH2Cl2, 2·CH2Cl2, 3 and 4 have been determined by single-crystal X-ray diffraction.  相似文献   

8.
The reactions of 1 mol equiv. each of [Ru(PPh3)3Cl2] and N-(acetyl)-N′-(5-R-salicylidene)hydrazines (H2ahsR, R = H, OCH3, Cl, Br and NO2) in alcoholic media afford simultaneously two types of complexes having the general formulae [Ru(HahsR)(PPh3)2Cl2] and [Ru(ahsR)(PPh3)2Cl]. The complexes have been characterized by elemental analysis, magnetic, spectroscopic and electrochemical measurements. Molecular structures of [Ru(HahsH)(PPh3)2Cl2] and [Ru(ahsH)(PPh3)2Cl] have been confirmed by X-ray crystallography. In both species, the PPh3 ligands are trans to each other. The bidentate HahsH coordinates to the metal ion via the O atom of the deprotonated amide and the imine–N atom in [Ru(HahsH)(PPh3)2Cl2]. In HahsH, the phenolic OH is involved in a strong intramolecular hydrogen bond with the uncoordinated amide N atom forming a seven-membered ring. In [Ru(ahsH)(PPh3)2Cl], the tridentate ahsH2− binds to the metal ion via the deprotonated amide O, the imine N and the phenolate O atoms. In the electronic spectra, the green [Ru(HahsR)(PPh3)2Cl2] and brown [Ru(ahsR)(PPh3)2Cl] complexes display several absorptions in the ranges 385–283 and 457–269 nm, respectively. Both complexes are low-spin and display rhombic EPR spectra in frozen solutions. Both types of complexes are redox active and display a quasi-reversible ruthenium(III) to ruthenium(II) reduction which is sensitive to the polar effect of the substituent on the chelating ligand. The reduction potentials are in the ranges −0.21 to −0.12 and −0.42 to −0.21 V (versus Ag/AgCl) for [Ru(HahsR)(PPh3)2Cl2] and [Ru(ahsR)(PPh3)2Cl], respectively.  相似文献   

9.
《Polyhedron》1987,6(11):2009-2018
A new bidentate ligand {2-(diphenylphosphino)ethyl}benzylamine(DPEBA) was synthesized and characterized based on the IR, mass and 1H, 13C and 31P NMR spectra. Various complexes of platinum group metal ions and Ni(II) and Co(II) ions with the ligand were synthesized. Reaction of RuCl2(PPh3)3 or RuCl2(Me2SO)4 with the ligand DPEBA, resulted in formation of a penta-coordinate, Ru(II) species of the composition [RuCl(DPEBA)2]Cl. Carbonylation of [RuCl(DPEBA)2]Cl gave an octahedral carbonyl complex of the type [RuCl(CO)(DPEBA)2]Cl. The reaction of RuCl3·3H2O or RuCl3(AsPh3)2MeOH with a twofold excess of the ligand gave an octahedral Ru(III) cationic species [Ru(DPEBA)2Cl2]Cl. Carbonylation of the Ru(III) complex gave rise to a carbonyl complex [RuCl(CO)(DPEBA)2]Cl2. The ligand DPEBA reacts with cobalt(II) chloride in methanol to give the 1 : 1 complex [Co(DPEBA)Cl2]. A series of Rh(I) complexes [Rh(DPEBA)2Cl], [ RhCl(CO)(DPEBA)] and [Rh(DPEBA)2]Cl were synthesized by the reaction of DPEBA with RhCl(PPh3)3, RhCl(CO)(PPh3)2 and [Rh(COD)Cl]2, respectively. Reaction of [Ir(COD)Cl]2 and IrCl(CO)(PPh3)2 with the ligand DPEBA, gave the square-planar complexes [Ir(DPBA)2]Cl and [Ir(DPEBA)(CO)Cl], respectively. Octahedral cationic complexes of the type [M(DPEBA)2Cl2]Cl (M = Rh(III), Ir(III)) were synthesized by the reaction of the ligand DPEBA and rhodium and iridium trichlorides. Reaction of NiCl2·6H2O with DPEBA in 1 : 2 molar equivalents, in boiling butanol gave an octahedral neutral complex [Ni(DPEBA)2Cl2] which readily rearranges to the square-planar complex [Ni(DPEBA)2]Cl2 in methanol. Reaction of Pd(II) and Pt(II) chlorides with DPEBA gave square-planar, cationic complexes of the type [M(DPEBA)2Cl]Cl (M = Pd, Pt). All the complexes were characterized on the basis of their analytical and spectral data.  相似文献   

10.
Four Ru(II) complexes with tridentate ligands viz. (4-hydroxy-N′-(pyridin-2-yl-ethylene) benzohydrazide [Ru(L1)(PPh3)2(Cl)] (1), N′-(pyridin-2-yl-methylene) nicotinohydrazide [Ru(L2)(PPh3)2(Cl)] (2), N′-(1H-imidazol-2-yl-methylene)-4-hydroxybenzohydrazide [Ru(L3)(PPh3)2(Cl)] (3), and N′-(1H-imidazol-2-yl-methylene) nicotinohydrazide [Ru(L4)(PPh3)2(Cl)] (4) have been synthesized and characterized. The methoxy-derivative of L3H (abbreviated as L3H*) exists in E configuration with torsional angle of 179.4° around C7-N8-N9-C10 linkage. Single crystal structures of acetonitrile coordinated ruthenium complexes of 1 and 3 having compositins as [Ru(L1)(PPh3)2(CH3CN)]Cl (1a) and [Ru(L3)(PPh3)2(CH3CN)]Cl (3a) revealed coordination of tridentate ligands with significantly distorted octahedral geometry constructed by imine nitrogen, heterocyclic nitrogen, and enolate amide oxygen, forming a cis-planar ring with trans-placement of two PPh3 groups and a coordinated acetonitrile. Ligands (L1H-L4H) and their ruthenium complexes (1–4) are characterized by 1H, 13C, 31P NMR, and IR spectral analysis. Ru(II) complexes have reversible to quasi-reversible redox behavior having Ru(II)/Ru(III) oxidation potentials in the range of 0.40–0.71 V. The DNA binding constants determined by absorption spectral titrations with Herring Sperm DNA (HS-DNA) reveal that L4H and 1 interact more strongly than other ligands and Ru(II) complexes. Complexes 1–3 exhibit DNA cleaving activity possibly due to strong electrostatic interactions while 4 displays intercalation.  相似文献   

11.
Reactions of [Ru(PPh3)3Cl2] with 2-(benzylimino-methyl)-4-R-phenol (HRL, R = H, Cl, Br and OMe) in boiling methanol in presence of triethylamine afford ruthenium(II) complexes of general formula [Ru(RL)(PPh3)2(CO)Cl] in 57-64% yield. Microanalysis, spectroscopic (infrared, electronic and NMR) and cyclic voltammetric measurements have been used for the characterization of the complexes. Crystal structures of two representative complexes have been determined by X-ray crystallography. The carbonyl, the chloride, the N,O-donor RL and the two mutually trans PPh3 molecules assemble a distorted octahedral CClNOP2 coordination sphere around the metal centre in each complex. The complexes display the Ru(II) → Ru(III) oxidation in the potential range 0.62-1.16 V (vs. Ag/AgCl).  相似文献   

12.
Reaction of 2-(phenylazo)pyridine (pap) with [Ru(PPh3)3X2] (X = Cl, Br) in dichloromethane solution affords [Ru(PPh3)2(pap)X2]. These diamagnetic complexes exhibit a weakdd transition and two intense MLCT transitions in the visible region. In dichloromethane solution they display a one-electron reduction of pap near − 0.90 V vs SCE and a reversible ruthenium(II)-ruthenium(III) oxidation near 0.70 V vs SCE. The [RuIII(PPh3)2(pap)Cl2]+ complex cation, generated by coulometric oxidation of [Ru(PPh3)2(pap)Cl2], shows two intense LMCT transitions in the visible region. It oxidizes N,N-dimethylaniline and [RuII(bpy)2Cl2] (bpy = 2,2′-bipyridine) to produce N,N,N′,N′-tetramethylbenzidine and [RuIII(bpy)2Cl2]+ respectively. Reaction of [Ru(PPh3)2(pap)X2] with Ag+ in ethanol produces [Ru(PPh3)2(pap)(EtOH)2]2+ which upon further reaction with L (L = pap, bpy, acetylacetonate ion(acac) and oxalate ion (ox2−)) gives complexes of type [Ru(PPh3)2(pap)(L)]n+ (n = 0, 1, 2). All these diamagnetic complexes show a weakdd transition and several intense MLCT transitions in the visible region. The ruthenium(II)-ruthenium(III) oxidation potential decreases in the order (of L): pap > bpy > acac > ox2−. Reductions of the coordinated pap and bpy are also observed.  相似文献   

13.
The syntheses, structures, spectroscopy, and electrochemistry for six Ir(III) and Rh(III) mixed sandwich mononuclear complexes involving tridentate macrocycles and pentamethylcyclopentadienide (Cp*) are reported. The complexes are readily prepared by direct ligand substitution reactions from the dichloro bridged binuclear complexes, [{M(Cp*)(Cl)2}2]. All complexes have the general formula [M(L)(Cp*)]X2 (M = Ir(III) or Rh(III), L = macrocycle, or Cl) and exhibit a distorted octahedral structure involving three donor atoms from the macrocycle and the facially coordinating carbocyclic Cp* ligand. The complex cations include: [Rh(η5 -Cp*)(9S3)]2+ (1), [Rh(η5-Cp*)(9N3)]2+ (2), [Rh(η5-Cp*)(10S3)]2+ (3), [Ir(η5-Cp*)(9S3)]2+ (4), [Ir(η5-Cp*)(9N3)]2+ (5), and [Ir(η5-Cp*)(10S3)]2+ (6), where 9S3 = 1,4,7-trithiacyclononane, 9N3 = 1,4,7-triazacyclononane, and 10S3 = 1,4,7-trithiacyclodecane. The structures for all six complexes are supported by 1H and 13C{1H} NMR spectroscopy, and five complexes are also characterized by single-crystal X-ray crystallography (complexes 1-5). The 1H NMR splittings between the two sets of methylene protons for both the Rh(III) and Ir(III) 9S3 complexes are much larger (0.4 vs. 0.2 ppm) compared to those in the two 9N3 complexes. Similarly, the 13C{1H} NMR spectra in all four thioether complexes show that the ring carbons in the Cp* ligand are shifted by over 10 ppm downfield compared to the azacrown complexes. The electrochemistry of the complexes is surprisingly invariable and is dominated by a single irreversible metal-centered reduction near −1.2 V vs. Fc/Fc+.  相似文献   

14.
Dinuclear Palladium(II), Platinum(II), and Iridium(III) Complexes of Bis[imidazol‐4‐yl]alkanes The reaction of bis(1,1′‐triphenylmethyl‐imidazol‐4‐yl) alkanes ((CH2)n bridged imidazoles L(CH2)nL, n = 3–6) with chloro bridged complexes [R3P(Cl)M(μ‐Cl)M(Cl)PR3] (M = Pd, Pt; R = Et, Pr, Bu) affords the dinuclear compounds [Cl2(R3P)M–L(CH2)nL–M(PR3)Cl2] 1 – 17 . The structures of [Cl2(Et3P)Pd–L(CH2)3L–Pd(PEt3)Cl2] ( 1 ), [Cl2(Bu3P)Pd–L(CH2)4L–Pd(PBu3)Cl2] ( 10 ), [Cl2(Et3P)Pd–L(CH2)5L–Pd(PEt3)Cl2] ( 3 ), [Cl2(Et3P)Pt–L(CH2)3L–Pt(PEt3)Cl2] ( 13 ) with trans Cl–M–Cl groups were determined by X‐ray diffraction. Similarly the complexes [Cl2(Cp*)Ir–L(CH2)nL–Ir(Cp*)Cl2] (n = 4–6) are obtained from [Cp*(Cl)Ir(μ‐Cl)2Ir(Cl)Cp*] and the methylene bridged bis(imidazoles).  相似文献   

15.
The cationic ruthenium complexes [(η5-C5H5)Ru(Ph2PCH2CH2PPh2)L]PF6 (L=olefin, CO, pyridine or acetonitrile) have been prepared by treatment of (η5-C5H5)Ru(Ph2PCH2CH2PPh2)Cl with L and NH4PF6 in methanol of 20°C.  相似文献   

16.
The novel complexes 4a and b have been synthesized by complexation of Ru(II) with the tridentate ligands Ph2P-(CH2)n-P(Ph)-(CH2)2-Cp (n = 3,4). 4b, compared with other Ru(II) phosphane complexes, showed superior capacity as hydrogenation catalyst.  相似文献   

17.
Three unsymmetrical tetradentate Schiff base ligands, H2salipn, H2salipn-Br4 and H2salipn-Cl2, have been synthesized from the typical condensation reactions of treating 1,2-diaminopropane with salicylaldehyde, 3,5-dibromosalicylaldehyde and 5-chlorosalicylaldehyde, respectively. Treatment of [RuCl2(PPh3)3] with one equivalent of H2salipn or H2salipn-Br4 in the presence of triethylamine in tetrahydrofuran (THF) afforded the corresponding ruthenium(III) complexes [RuIIICl(PPh3)(salipn)] (1) and [RuIIICl(PPh3)(salipn-Br4)] (2). Interaction of [RuHCl(CO)(PPh3)3] with one equivalent of H2salipn-Cl2 or H2salipn-Br4 under the same conditions led to isolation of ruthenium(II) complexes [RuII(CO)(PPh3)(salalipn-Cl2)] (3) and [RuII(CO)(PPh3)(salalipn-Br4)] (4), respectively, in which one of the imine bonds was nucleophilically attacked by hydride to result in the formation of a mixed imine-amine ligand. The molecular structures of 1?1.5CH2Cl2, 2, 3?0.5CH2Cl2 and 4 have been determined by single-crystal X-ray crystallography. The electrochemical properties of 14 were also investigated. Their cyclic voltammograms displayed quasi-reversible Ru(IV)/Ru(III) and Ru(III)/Ru(II) couples with Eo ranging from 0.67 to 1.05 V and 0.74 to 0.80 V vs. Ag/AgCl (0.1 M), respectively.  相似文献   

18.
Dechlorination of Ru(PPh3)2(TaiMe)Cl2 (TaiMe = p-Me-C6H4-N=N-C3H2NN(1)-Me (1), 1-methyl-2-(p-tolylazo)imidazole) has been carried out in acetone solution by Ag+ and reacted with N,N’-chelators to synthesise [Ru(PPh3)2 (TaiMe)(N,N’)]2+. The complexes have been isolated as their perchlorate salts. The N,N’ chelators are 1-alkyl-2-(phenylazo)imidazoles (PaiX, X = Me, Et, CH2Ph); 2-(arylazo)pyridines, (Raap,p-R-C6H4-N=N-C5H4N; R = H, Me, Cl); 2-(arylazo)pyrimidines (Raapm,p-R-C6H4-N=N-C3N2H2; R = H, Me, Cl); 2,2’-bipyridine (bpy) and 1,10-phenanthroline (o-phen). Unsymmetrical N,N’ chelators may give two isomers and this is indeed observed. The1H NMR spectral data refer to the presence of two isomers in the mixture in different proportions. With consideration of coordination pairs in the order of PPh3, PPh3; N,N (N refers to N(immidazole)) and N’,N (N’ refers to N(azo)), the complexes have been characterised astrans-cis-cis andtrans-trans-trans configuration; the former predominates in the mixture. Electrochemical studies exhibit high potential Ru(III)/Ru(II) couple and quasireversible N=N reduction. Electronic spectra show high intensity (ε ∼ 104) MLCT transition in the visible region (520 ±10) nm along with a shoulder (ε ∼ 103) in the longer wavelength region.  相似文献   

19.
Reaction of α-amino acids (HL) with [Ru(PPh3)3Cl2] in the presence of a base afforded a family of complexes of type [Ru(PPh3)2(L)2]. These complexes are diamagnetic (low-spin d6, S=0) and show ligand-field transitions in the visible region. 1H and 31P NMR spectra of the complexes indicate the presence of C2 symmetry. Cyclic voltammetry on the [Ru(PPh3)2(L)2] complexes show a reversible ruthenium(II)–ruthenium(III) oxidation in the range 0.30–0.42 V vs. SCE. An irreversible ruthenium(III)–ruthenium(IV) oxidation is also displayed by two complexes near 1.5 V vs. SCE.  相似文献   

20.
The synthesis, characterization and chemistry of novel η3-allyl metal complexes (M = Ir, Rh) are described. The structures of compounds (C5Me4H)Ir(PPh3)Cl2 (1), (C5Me4H)Ir(PPh3)(η3-1-methylallyl)Br (3a), (C5Me4H)Ir(η4-1,3,5-hexatriene) (8), and (C5Me5)Rh(η3-1-ethylallyl)Br (5d) have been determined by X-ray crystallography. Structural comparisons among these complexes are discussed. It is found that the neutral metal allylic complex [CpIrCl(η3-methylallyl)] (5) ionizes in polar solvents to give [CpIr(η3-methylallyl)]+Cl (6) and reaches equilibrium (5 ? 6) at room temperature. Addition of tertiary phosphine ligands to neutral complexes such as [CpIr(η3-methylallyl)Cl], results in the formation of stable ionic phosphine adducts. Factors such as solvent, length of carbon chain, temperature and light are discussed with respect to the formation, stability and structure of the allyl complexes.  相似文献   

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