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1.
The reactions of [Ru(H)(Cl)(CO)(PPh3)3] with 3,5-di-tert-butyl-o-benzoquinone (dbq) and 3,4,5,6-tetrachloro-o-benzoquinone (tcq) have afforded the corresponding semiquinone complexes [RuII(dbsq)(Cl)(CO)(PPh3)2] and [RuII(tcsq)(Cl)(CO)(PPh3)2], respectively. The reaction of [Ru(H)2(CO)(PPh3)3] with tcq has furnished [RuII(tcsq)(H)(CO)(PPh3)2]. Structure determination of [Ru(dbsq)(Cl)(CO)(PPh3)2] has revealed that it is a model semiquinonoid chelate with two equal C---O lengths ( 1.291(6) and 1.296(6) Å). The complexes are one-electron paramagnetic (1.85μB) and their EPR spectra in fluid media display a triplet structure (g2.00) due to superhyperfine coupling with two trans-31P atoms (Aiso17 G). The stretching frequency of the CO ligand increases by 20 cm−1 in going from [Ru(dbsq)(Cl)(CO)(PPh3)2] to [Ru(tcsq)(Cl)(CO)(PPh3)2] consistent with electron withdrawal by chloro substituents. For the same reason the E1/2 values of the cyclic voltammetric quinone/semiquinone and semiquinone/catechol couples undergo a shift of 500 mV to higher potentials between [Ru(dbsq)(Cl)(CO)(PPh3)2] and [Ru(tcsq)(Cl)(CO)(PPh3)2].  相似文献   

2.
Synthetic procedures are described that allow access to the new complexes cis-[Mo2O5(apc)2], cis-[WO2(apc)2], trans-[UO2(apc)2], [Ru(apc)2(H2O)2], [Ru(PPh3)2(apc)2], [Rh(apc)3], [Rh(PPh3)2(apc)2]ClO4, [M(apc)2], [M(PPh3)2(apc)]Cl, [M(bpy)(apc)]Cl (M(II) = Pd, Pt), [Pd(bpy)(apc)Cl], [Ag(apc)(H2O)2] and [Ir(bpy)(Hapc)2]Cl3, where Hapc, is 3-aminopyrazine-2-carboxylic acid. These complexes were characterized by physico-chemical and spectroscopic techniques. Both Hapc and several of its complexes display significant anticancer activity against Ehrlich ascites tumour cells (EAC) in albino mice.  相似文献   

3.
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   

4.
Summary Using 1,2-naphthoquinone-1-oxime (HL) as the principal ligand, four mixed-ligand ruthenium oximate complexes - namely [Ru(bipy)2(L)]ClO4, [Ru(pap)2(L)]-ClO4, [Ru(bipy)(L)2] and [Ru(PPh3)2(L)2], where bipy = 2,2′-bipyridine and pap = 2-(phenylazo)pyridine- have been synthesized and characterized. In all these complexes, Ru exists in the +2 state. They are diamagnetic and, in solution, show several intense metal-to-ligand charge transfer (MLCT) transitions in the vis. region. In MeCN solution, all four complexes show a reversible RuII-RuIII oxidation on the positive side of a standard calomel electrode (s.c.e.), the potential of which varies with the compositions of the complexes. Reductions of the coordinated co-ligands (bipy or pap) are also observed.  相似文献   

5.
Summary Nine complexes of FeIIRuII with bis(tertiary phosphines), namely, 1,2-bis(diphenylphosphino)ethane (dppe), 1,2-bis (diphenylphosphino)ethylene (dppen) and o-phenylenebis (diphenylphosphine) (o-diphos) were studied using cyclic voltammetry. The half-wave potentials for the complexes studied are: (1) [FeCl2(dppe)], 0.050V; (2) [Fe(NCS)2(dppe)2], 0.265V; (3) [RuCl2(dppe)2], 0.548V; (4) [FeCl2(dppen)2], 0.225V; (5) [Fe(NCS)2-(dppen)2], 0.290V; (6) [RuCl2(dppen)2], 0.690V; (7) [FeCl2(o-diphos)2] 0.160V; (8) [Fe(NCS)2(o-diphos)2] 0.582V; and (9) [RuCl2(o-diphos)2], 0.265V. The redox potentials are related to the nature of the ligand, the nature of the metal, the stereochemistry of the complex and the ligand field strength.  相似文献   

6.
Reaction of Ru(CO)Cl(CHCHR)(PPh3)2 or Ru(CO)Cl(CHCHR)(PPh3)2L (L = py, Me2Hpz) with 1 equivalent of t-butyl isocyanide gives the alkenyl derivatives Ru(CO)Cl(CHCHR)(PPh3)2(t-BuNC). When an excess of isocyanide is used, further reaction results in intramolecular CO insertion to yield η1-acyl complexes [Ru(COCHCHR) (t-BuNC)3(PPh3)2]Cl. Related complexes were obtained from [Ru(CO)(CHCHR)(MeCN)2(PPh3)2]PF6 and an excess of isocyanide.  相似文献   

7.
Geometrical structures of nitroso complexes trans- [Ru(NO)(NH3)4(Cl)]2+, trans-[Ru(NO)(NH3)4(H2O)]3+, [Ru(NO)(Cyclam)(Cl)]2+(Cyclam is 1,4,8,11-tetraazocyclodecane), and [Ru(NO)(Bipy)2(Cl)]2+ (Bipy is 2,2-bipyridine) are optimized using the density functional method. The potential energy surface of all four complexes was found to contain local minima corresponding to a stable state with the 1-coordination of NO through the N atom and to two metastable isomers with the 1-O and 2-NO coordination. For [Ru(NO)Cl5)]2-, trans-[Ru(NO)(NH3)4(Cl)]2+, and trans-[Ru(NO)(NH3)4(H2O)]3+, the lowest electronically excited triplet states are calculated, as well as the reduced complexes with one additional electron. It is shown that the electron excitation and reduction are accompanied by bending of the RuNO group with a substantial elongation of the Ru-O and N-O bonds, which makes this group unstable. These processes do not cause any significant changes in the metal or in the nitroso ligand oxidation states because of the electron density delocalization in the RuNO group.Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 1, 2005, pp. 32–42.Original Russian Text Copyright © 2005 by Sizova, Lubimova.  相似文献   

8.
The mono-bipyridine bis carbonyl complex [Ru(bpy)(CO)2Cl2] exists in two stereoisomeric forms having a trans(Cl)/cis(CO) (1) and cis(Cl)/cis(CO) (2) configuration. In previous work we reported that only the trans(Cl)/cis(CO) isomer 1 leads by a two-electron reduction to the formation of [Ru(bpy)(CO)2]n polymeric film on an electrode surface. This initial statement was overstated, as both isomers allowed the build up of polymers. A detailed comparison of the electropolymerization of both isomers is reported here, as well as the reduction into dimers of parent stereoisomer [Ru(bpy)(CO)2(C(O)OMe)Cl] complexes 3 and 4 obtained as side products during the synthesis of 1 and 2.  相似文献   

9.
Summary The syntheses of new dinuclear and mononuclear complexes of RuII trifluoroacetate containing monodentate co-ligands, namely [Ru2(-O2CCF3)4L2] (L = py, 2-Mepy or 3-Mepy); trans-[Ru(O2CCF3)2L4] (L = 2-Mepy or 3-Mepy); [Ru(O2CCF3)(PPh3)4](O2CCF3) and [Ru(O2CCF3)2(CO)(MPh3)3] (M = P or As), are described. The complexes have been characterized by physical and electrochemical studies.  相似文献   

10.
Spectral and kinetic parameters were studied for phosphine-bipyridyl ruthenium(II) complexes, namely, cis-[Ru(Bipy)2(PPh3)X](BF4), cis-[Ru(Bipy)(Dppe)X2], and cis-[Ru(Bipy)(Dppene)X2] (where Bipy is 2,2"-bipyridyl, PPh3is triphenylphosphine, Dppe is 1,2-bis(diphenylphosphino)ethane, and Dppene iscis-1,2-bis(diphenylphosphino)ethylene; X = CN, NO2 ), in the frozen (77 K) alcohol glasses (EtOH–MeOH, 4 : 1). The energies of the singlet and triplet metal-to-ligand charge transfer states d(Ru) *(Bipy) were found to increase in the order [Ru(Bipy)2X2] < [Ru(Bipy)2(PPh3)X]+< [Ru(Bipy)(Dppe)X2] < [Ru(Bipy)(Dppene)X2]. The luminescence quantum yields and the rate constants of the nonradiative deactivation of the lowest excited state 3MLCT increase in the same order.  相似文献   

11.
《Polyhedron》1995,14(23-24)
New complexes of bivalent nickel with isopropylxanthates and nitrogen-donor ligands of composition [Ni(Prixa)2(L)], [Ni(Prixa)2(L1)2], [Ni(L2)2](Prixa)2, and [Ni(L3)3] (Prixa)2 have been synthesized, where Prixa = i-C3H7OCS2, L = 1,2-diaminopropane (1,2-pn), N,N,N′,N′=tetramethylethylenediamine (tmen) or 4,4′-bipyridine (4,4′-bipy), L1 = pyridine (py), L2 = diethylenetriamine (dien) and L3 = ethylenediamine (en), 1,2-diaminopropane or 1,10-phenanthroline (phen). The compounds have been characterized by elemental analysis, IR and UV-vis spectroscopy, magnetochemical measurements, molar conductivity and thermal analysis. The compounds containing the complex cation have been one-electron irreversibly oxidized using cyclic voltammetry. The crystal and molecular structures of [Ni(Prixa)2(tmen)] and [Ni(phen)3](Prixa)2 have been elucidated.  相似文献   

12.
The reaction of the Schiff bases (obtained by condensing isatin with o‐aminophenol/o‐aminothiophenol/o‐aminobenzoic acid) with [RuX3(EPh3)3] (where X = Cl/Br; E = P/As) in benzene afforded new, air‐stable Ru(III) complexes of the general formula [Ru(L)X(EPh3)2] (L = dianion of tridentate Schiff bases). In all these reactions, the Schiff base ligand replaces one triphenylphosphine/triphenylarsine and two chlorides/bromides from the ruthenium precursors. The complexes were characterized by elemental analyses, spectral (FT–IR, UV–vis, 1H and 13C NMR for the ligands, and EPR) and electrochemical studies. All the metal complexes exhibit characteristic LMCT absorption bands in the visible region. The catalytic reactivity proved these complexes to be efficient catalysts in the oxidation of alcohols and C? C coupling. All the complexes were screened for their biocidal efficiency against bacteria such as Staphylococcus epidermidis and Escherichia coli and fungi such as Botrytis cinerea and Aspergillus niger at 0.25, 0.50 and 1% concentrations. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

13.
[Pd(cod)(cotl)]ClO4 (cod = 1,5-cyclooctadiene, cotl = cyclooctenyl, C8H13 ) undergoes substitutions with multidentate N-heterocycles: 1,3-bis(benzimidazolyl)benzene (L1), 1,3-bis(1-methylbenzimidazol-2-yl)benzene (L2), 2,6-bis(benzimidazolyl)pyridine (L3) and 2,6-bis(1-methylbenzimidazol-2-yl)pyridine (L4) to yield mono/binuclear complexes: [Pd(cotl)(L1)(OClO3)], [Pd(cotl)(L)]ClO4 (L = L2 or L3) and [Pd(cotl)2(L4)](ClO4)2. Dihalobridged binuclear complexes [PdX(cotl)]2 (X = Cl or Br) undergo halogen bridge cleavages with the multidentate N-heterocycles to form binuclear complexes of the type [PdX(cotl)2L] (X = Cl or Br; L = L1, L2, L3 or L4). The complexes were characterized by elemental analyses, 1H-, 13C-n.m.r., i.r., far-i.r. and FAB-mass spectral studies.  相似文献   

14.
New compounds [Ru(pap)2(L)](ClO4), [Ru(pap)(L)2], and [Ru(acac)2(L)] (pap=2‐phenylazopyridine, L?=9‐oxidophenalenone, acac?=2,4‐pentanedionate) have been prepared and studied regarding their electron‐transfer behavior, both experimentally and by using DFT calculations. [Ru(pap)2(L)](ClO4) and [Ru(acac)2(L)] were characterized by crystal‐structure analysis. Spectroelectrochemistry (EPR, UV/Vis/NIR), in conjunction with cyclic voltammetry, showed a wide range of about 2 V for the potential of the RuIII/II couple, which was in agreement with the very different characteristics of the strongly π‐accepting pap ligand and the σ‐donating acac? ligand. At the rather high potential of +1.35 V versus SCE, the oxidation of L? into L. could be deduced from the near‐IR absorption of [RuIII(pap)(L.)(L?)]2+. Other intense long‐wavelength transitions, including LMCT (L?→RuIII) and LL/CT (pap.?→L?) processes, were confirmed by TD‐DFT results. DFT calculations and EPR data for the paramagnetic intermediates allowed us to assess the spin densities, which revealed two cases with considerable contributions from L‐radical‐involving forms, that is, [RuIII(pap0)2(L?)]2+?[RuII(pap0)2(L.)]2+ and [RuIII(pap0)(L?)2]+?[RuII(pap0)(L?)(L?)]+. Calculations of electrogenerated complex [RuII(pap.?)(pap0)(L?)] displayed considerable negative spin density (?0.188) at the bridging metal.  相似文献   

15.
Reaction of 1-(2′-pyridylazo)-2-naphthol (Hpan) with [Ru(dmso)4Cl2] (dmso = dimethylsulfoxide), [Ru(trpy)Cl3] (trpy = 2,2′,2″-terpyridine), [Ru(bpy)Cl3] (bpy = 2,2′-bipyridine) and [Ru(PPh3)3Cl2] in refluxing ethanol in the presence of a base (NEt3) affords, respectively, the [Ru(pan)2], [Ru(trpy)(pan)]+ (isolated as perchlorate salt), [Ru(bpy)(pan)Cl] and [Ru(PPh3)2(pan)Cl] complexes. Structures of these four complexes have been determined by X-ray crystallography. In each of these complexes, the pan ligand is coordinated to the metal center as a monoanionic tridentate N,N,O-donor. Reaction of the [Ru(bpy)(pan)Cl] complex with pyridine (py) and 4-picoline (pic) in the presence of silver ion has yielded the [Ru(bpy)(pan)(py)]+ and [Ru(bpy)(pan)(pic)]+ complexes (isolated as perchlorate salts), respectively. All the complexes are diamagnetic (low-spin d6, S = 0) and show characteristic 1H NMR signals and intense MLCT transitions in the visible region. Cyclic voltammetry on all the complexes shows a Ru(II)–Ru(III) oxidation on the positive side of SCE. Except in the [Ru(pan)2] complex, a second oxidative response has been observed in the other five complexes. Reductions of the coordinated ligands have also been observed on the negative side of SCE. The [Ru(trpy)(pan)]ClO4, [Ru(bpy)(pan)(py)]ClO4 and [Ru(bpy)(pan)(pic)]ClO4 complexes have been observed to bind to DNA, but they have not been able to cleave super-coiled DNA on UV irradiation.  相似文献   

16.
New Mannich bases bis(thiosemicarbazide methyl) phosphinic acid H3L1 and bis(1-phenylsemicarbazide methyl) phosphinic acid H3L2 were synthesized from condensation of phosphinic acid and formaldehyde with thiosemicarbazide and 1-phenylsemicarbazide, respectively. Monomeric complexes of these ligands, of general formula K2[CrIII(L n )Cl2], K3[FeII(L1)Cl2], K3[MnII(L2)Cl2], and K[M(L n )] (M = Co(II), Ni(II), Cu(II), Zn(II) or Cd(II); n = 1, 2) are reported. The mode of bonding and overall geometry of the complexes were determined through IR, UV-Vis, NMR, and mass spectral studies, magnetic moment measurements, elemental analysis, metal content, and conductance. These studies revealed octahedral geometries for the Cr(III), Mn(II), and Fe(II) complexes, square planar for Co(II), Ni(II), and Cu(II) complexes and tetrahedral for the Zn(II) and Cd(II) complexes. Complex formation via molar ratio in DMF solution has been investigated and results were consistent to those found in the solid complexes with a ratio of (M : L) as (1 : 1).  相似文献   

17.
A new class of half‐sandwich (η6p‐cymene) ruthenium(II) complexes supported by 2‐aminofluorene derivatives [Ru(η6p‐cymene)(Cl)(L)] ( L  = 2‐(((9H‐fluoren‐2‐yl)imino)methyl)phenol ( L 1 ), 2‐(((9H‐fluoren‐2‐yl)imino)methyl)‐3‐methoxyphenol ( L 2 ), 1‐(((9H‐fluoren‐2‐yl)imino)methyl)naphthalene‐2‐ol ( L 3 ) and N‐((1H‐pyrrol‐2‐yl)methylene)‐9H‐fluorene‐2‐amine ( L 4 )) were synthesized. All compounds were fully characterized by analytical and spectroscopic techniques (IR, UV–Vis, NMR) and also by mass spectrometry. The solid state molecular structures of the complexes [Ru(η6p‐cymene)(Cl)(L2)], [Ru(η6p‐cymene)(Cl)(L3)] and [Ru(η6p‐cymene)(Cl)(L4)] revealed that the 2‐aminofluorene and p‐cymene moieties coordinate to ruthenium(II) in a three‐legged piano‐stool geometry. The synthesized complexes were used as catalysts for the dehydrogenative coupling of benzyl alcohol with a range of amines (aliphatic, aromatic and heterocyclic). The reactions were carried out under thermal heating, ultrasound and microwave assistance, using solvent or solvent free conditions, and the catalytic performance was optimized regarding the solvent, the type of base, the catalyst loading and the temperature. Moderately high to very high isolated yields were obtained using [Ru(η6p‐cymene)(Cl)(L4)] at 1 mol%. In general, microwave irradiation produced better yields than the other two techniques irrespective of the nature of the substituents.  相似文献   

18.
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   

19.
We report herein synthesis and characterization of four new organoruthenium(II) complexes of the type [RuH(CO)(PPh3)2(L1,2)]Cl (1, 3) and [Ru(CO)(Cl)2(AsPh3)(L1,2)] (2, 4) derived from the reaction of [RuHCl(CO)(EPh3)3] (E = P or As) with 2-(pyridine-2yl)benzoxazole (L1) and 2-(pyridine-2yl)benzthiazole (L2). Single-crystal X-ray diffraction data of 2 proved octahedral geometry of the complexes with a 1?:?1 ratio between the metal and the coordinated ligands. The binding affinities of 14 toward calf-thymus DNA (CT-DNA) and BSA were thoroughly studied by various spectroscopic techniques. Furthermore, the coordination compounds exhibit catecholase-like activities in the aerial oxidation of 3,5-di-tert-butylcatechol to the corresponding o-quinone and phosphatase-like activities in the hydrolysis of 4-nitrophenyl phosphate to 4-nitrophenolate ion. The kinetic parameters have been determined using Michaelis–Menten approach. The highest kcat values suggested that coordination compounds exhibit higher rates of catalytic efficacy.  相似文献   

20.
Summary Ruthenium(III) complexes of types [Ru(L)3], [Ru(L)Cl(H2O)2], [Ru(L)Cl2]n, [Ru(L)Cl(H2O)]n(LH =Schiff bases derived from anthranilic acid and benzaldehyde, acetophenone, vanillin, cinnamaldehyde orm-hydroxyacetophenone; LH2=Schiff bases derived from anthranilic acid and salicylaldehyde oro-hydroxyacetophenone; LH=Schiff bases derived fromp-aminobenzoic acid and benzaldehyde, acetophenone, vanillin, cinnamaldehyde orm-hydroxyacetophenone; LH2=Schiff bases derived fromp-aminobenzoic acid and salicylaldehyde oro-hydroxyacetophenone) have been synthesized and characterized on the basis of elemental analyses, conductance, magnetic moment and spectral (electronic, i.r. and1H n.m.r.) data. The wavelengths of the principal electronic absorption peaks have been accounted for quantitatively in terms of crystal field theory and various parameters have been evaluated. On the basis of the electronic spectra, an octahedral geometry has been established for all these complexes except [Ru(L)Cl2]n. The complexes [Ru(L)Cl2]n are pentacoordinate and a trigonal-bipyramidal environment, D3h, is suggested for the ruthenium(III) ion. The thermal behaviour of these complexes has also been studied by t.g., d.t.g and d.s.c techniques. Heats of reaction for the decomposition steps were calculated from the d.s.c. curves. The antifungal and antiviral activities of the complexes with Schiff bases derived from anthranilic acid were also investigated.  相似文献   

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