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1.
Paramagnetic Ru(III) complexes of the type [RuX2(EPh3)2(L)] (where X = Cl or Br; E = P or As; L = monobasic bidentate benzophenone ligand) have been synthesized from the reaction of ruthenium(III) precursors, viz. [RuX3(EPh3)3] (where X = Cl, E = P; X = Cl or Br, E = As) or [RuBr3(PPh3)2(CH3OH)] and substituted hydroxy benzophenones in a 1:1 molar ratio in benzene under reflux for 6 h. The hydroxy benzophenone ligands behave as monoanionic bidentate O,O donors and coordinate to ruthenium through the phenolate oxygen and ketonic oxygen atoms, generating a six-membered chelate ring. The compositions of the complexes have been established by analytical and spectral (FT-IR, UV-Vis, EPR) and X-ray crystallography methods. The single crystal structure of the complex [RuCl2(PPh3)2(L1)] (1) has been determined by X-ray crystallography and indicates the presence of a distorted octahedral geometry in these complexes. The magnetic moment values of the complexes are in the range 1.75-1.89 μB, which reveals the presence of one unpaired electron in the metal ion. EPR spectra of liquid samples at liquid nitrogen temperature (LNT) show a rhombic distortion (gx ≠ gy ≠ gz) around the ruthenium ion. The complexes are redox active and display quasi-reversible oxidation and quasi-reversible reduction waves versus Ag/AgCl.  相似文献   

2.
The reaction of [RuHCl(CO)(B)(EPh3)2] (where E = As, B = AsPh3; E = P, B = PPh3, py, pip, or mor) and dehydroacetic acid thiosemicarbazone (abbreviated as H2dhatsc where H2 stands for the two dissociable protons) in benzene under reflux afford a series of new ruthenium(II) carbonyl complexes containing dehydroacetic acid thiosemicarbazone of general formula [Ru(dhatsc)(CO)(B)(EPh3)] (where E = As, B = AsPh3; E = P, B = PPh3, py, pip or mor; dhatsc = dibasic tridentate dehydroacetic acid thiosemicarbazone). All the complexes have been characterized by elemental analyses, FT-IR, UV-Vis, and 1H NMR spectral methods. The thiosemicarbazone of dehydroacetic acid behaves as dianionic tridentate O, N, S donor and coordinates to ruthenium via phenolic oxygen of dehydroacetic acid, the imine nitrogen of thiosemicarbazone and thiol sulfur. In chloroform solution, all the complexes exhibit metal-to-ligand charge transfer transitions (MLCT). The crystal structure of one of the complexes [Ru(dhatsc)(CO)(PPh3)2] (1) has been determined by single crystal X-ray diffraction which reveals the presence of a distorted octahedral geometry in the complexes. All the complexes exhibit an irreversible oxidation (RuIII/RuII) in the range 0.76-0.89 V and an irreversible reduction (RuII/RuI) in the range −0.87 to −0.97 V. Further, the free ligand and its ruthenium complexes have been screened for their antibacterial and antifungal activities. The complexes show better activity in inhibiting the growth of bacteria Staphylococcus aureus and Escherichia coli and fungus Candida albicans and Aspergillus niger. These results made it desirable to delineate a comparison between free ligand and its ruthenium complexes.  相似文献   

3.
Diamagnetic ruthenium(II) complexes of the type [Ru(L)(CO)(B)(EPh3)] [where E = As, B = AsPh3; E = P, B = PPh3, py (or) pip and L = dibasic tridentate ligands dehydroacetic acid semicarbazone (abbreviated as dhasc) or dehydroacetic acid phenyl thiosemicarbazone (abbreviated as dhaptsc)] were synthesized from the reaction of [RuHCl(CO)(B)(EPh3)2] (where E = As, B = AsPh3; E = P, B = PPh3, py (or) pip) with different tridentate chelating ligands derived from dehydroacetic acid with semicarbazide or phenylthiosemicarbazide. All the complexes have been characterized by elemental analysis, FT-IR, UV–Vis and 1H NMR spectral methods. The coordination mode of the ligands and the geometry of the complexes were confirmed by single crystal X-ray crystallography of one of the complexes [Ru(dhaptsc)(CO)(PPh3)2] (5). All the complexes are redox active and are monitored by cyclic voltammetric technique. Further, the catalytic efficiency of one of the ruthenium complexes (5) was determined in the case of oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide.  相似文献   

4.
A series of Ru(II) and Ru(III) complexes of the types [RuX(CO)(EPh3)2L] (X = H, E = P; X = Cl, E = P or As) and [RuX2(EPh3)2L] (X = Cl, E = P or As; X = Br, E = As, L = monoanion of dehydroacetic acid) have been synthesized in order to explore their biological activities, such as DNA-binding and antibacterial activity. The complexes were characterized by analytical and spectroscopic techniques. The crystal and molecular structure of [RuCl2(AsPh3)2(L)] has been determined by single crystal XRD. The cyclic voltammograms of the complexes in acetonitrile displayed either quasi-reversible or irreversible redox couples based on the metal centre. The ligand, dehydroacetic acid (DHA) and its metal complexes were tested against five pathogenic bacteria. Absorption titration and cyclic voltammetric studies revealed that the complexes interact with Herring Sperm ds DNA through different binding modes to different extents.  相似文献   

5.
Tungsten(VI) and molybdenum(VI) complexes [MO(L1)Cl2] and [M(X)(L2)Cl3] (X = O, NPh) with tridentate aminobis(phenolate) ligand L1 = methylamino-N,N-bis(2-methylene-4,6-dimethylphenolate) and bidentate aminophenolate ligand L2 = 2,4-di-tert-butyl-6-((dimethylamino)methyl)phenolate) were prepared and characterised. These complexes are principally stable in open atmosphere under ambient conditions. When activated with Et2AlCl, they exhibited high activity in ring-opening metathesis polymerisation (ROMP) of 2-norbornene (NBE) and its derivatives. Especially complexes [M(NPh)(L2)Cl3], which are easily available from corresponding metal oxides MO3 by a simple three-step synthesis, were found very efficient ROMP catalysts for NBE (M = Mo, W) and 2-norbornen-5-yl acetate (M = Mo).  相似文献   

6.
The [ReOX2(hbt)(EPh3)] (X = Cl, Br; E = As, P) chelates have been prepared in the reactions of [ReOX3(EPh3)2] complexes (X = Cl, Br; E = P, As) with 2-(2′-hydroxyphenyl)-2-benzothiazole (hbtH) in acetone. From the reactions of [ReOX3(PPh3)2] with hbtH two kind of crystals [ReOX2(hbt)(PPh3)] · MeCN and [ReOX2(hbt)(PPh3)] with different arrangement of halide ions (cis and trans) were isolated, whereas the [ReOX3(AsPh3)2] oxocompounds react with hbtH to give only cis-halide isomers. The complexes were structurally and spectroscopically characterised. The electronic structures of both [ReOBr2(hbt)(PPh3)] isomers have been calculated with the density functional theory (DFT) method. The TDDFT/PCM calculations have been employed to produce a hundred of singlet excited-states starting from the ground-state geometry optimized in the gas phase of cis- and trans-halide isomers of [ReOBr2(hbt)(PPh3)] and the UV–Vis spectra of these complexes have been discussed on this basis.  相似文献   

7.
New hexa-coordinated Ru(III) complexes of the type [Ru(H2Pzdc)(EPh3)3X2] have been synthesized by reacting 3,5-pyrazole dicarboxylic acid (H3Pzdc) with the appropriate starting complexes [RuX3(EPh3)3] (where X = Cl or Br; E = P or As). The ligand behaves as a bidentate monobasic chelate. All the complexes have been characterized by analytical and spectroscopic (IR, electronic and EPR) data. Single-crystal X-ray analysis of the complex [Ru(H2Pzdc)(PPh3)2Cl2]·C6H6·C2H5OH revealed that the coordination environment around the ruthenium center consists of an NOP2Cl2 octahedron. The planar ligand occupies the equatorial position along with two chlorine atoms, while the triphenylphosphine groups occupy the axial positions. The electrochemical behavior of the new complexes was studied using cyclic voltammetry. The new mononuclear ruthenium complexes are capable of acting as catalysts for the oxidation of alcohols.  相似文献   

8.
Novel [ReOX2(quin-2-c)(EPh3)] complexes (X = Cl, Br; E = As, P; quin-2-c = quinoline-2-carboxylate ion) have been prepared by treatment of [ReOX3(EPh3)2] with quinoline-2-carboxylic acid in acetone at room temperature. All the complexes were characterised by IR, UV–Vis spectroscopy and elemental analysis. The crystal and molecular structures have been determined for [ReOCl2(qiun-2c)(PPh3)] (1) and [ReOBr2(qiun-2c)(AsPh3)] (4). The electronic structure of 1 has been calculated with the density functional theory (DFT) method. The spin-allowed electronic transitions of 1 have been calculated with the time-dependent DFT method.  相似文献   

9.
Cyclometallated Ru(II) complexes of the type [Ru(CO)(EPh3)2(L)] (E = P or As; L = tridentate hydrazone-derived ligand) have been obtained by refluxing an ethanolic solution of [RuHCl(CO)(PPh3)3] or [RuHCl(CO)(AsPh3)3] with the hydrazone derivatives H2php (2-[(2,4-dinitro-phenyl)-hydrazonomethyl]-phenol), H2phm (2-[(2,4-dinitro-phenyl)-hydrazonomethyl]-6-methoxy-phenol) and H2phn (2-[(2,4-dinitro-phenyl)-hydrazonomethyl]-naphthalen-1-ol). The formation of stable cyclometallated complexes has been authenticated by single crystal X-ray structure determination of two of the complexes, and the mechanism of C–H activation is discussed in detail. The spectral (IR, UV–Vis and 1H NMR) and electrochemical data for all the complexes are reported. Electrochemistry shows a substantial variation in the metal redox potentials with regard to the electronic nature of the substituents present in the hydrazone derivative.  相似文献   

10.
N-thioamide thiosemicarbazone derived from 4-(methylthio)benzaldehyde (R = H, HL1; R = Me, HL2 and R = Ph, HL3) have been prepared and their reaction with fac-[ReX(CO)3(CH3CN)2] (X = Br, Cl) in methanol gave the adducts [ReX(CO)3(HLn)] (1a X = Cl, n = 1; 1a′ X = Br, n = 1; 1b X = Cl, n = 2; 1b′ X = Br, n = 2; 1c X = Cl, n = 3; 1c′ X = Br, n = 3) in good yield.All the compounds have been characterized by elemental analysis, mass spectrometry (ESI), IR and 1H NMR spectroscopic methods. Moreover, the structures of HL2, HL3, HL3·(CH3)2SO and 1b′·H2O were also elucidated by X-ray diffraction. In 1b′, the rhenium atom is coordinated by the sulphur and the azomethine nitrogen atoms (κS,N3) forming a five-membered chelate ring, as well as three carbonyl and bromide ligands. The resulting coordination polyhedron can be described as a distorted octahedron.The structure of the dimers is based on rhenium(I) thiosemicarbazonates [Re2(L1)2(CO)6] (2a), [Re2(L2)2(CO)6] (2b) and [Re2(L3)2(CO)6] (2c) as determined by X-ray studies. Methods of synthesis were optimized to obtain amounts of these thiosemicarbazonate complexes. In these compounds the dimer structures are achieved by Re-S-Re bridges, where S is the thiolate sulphur from a κS,N3-bidentate thiosemicarbazonate ligand.Some single crystals isolated in the synthesis of 2b contain [Re(L4)(L2)(CO)3] (3b) where L4 (=2-methylamine-5-(para-methylsulfanephenyl)-1,3,4-thiadiazole) is originated in a cyclization process of the thiosemicarbazone. Furthermore, the rhenium atom is coordinate by the sulphur and the thioamidic nitrogen of the thiosemicarbazonate (κS,N2) affording a four-membered chelate ring.  相似文献   

11.
Treatment of [RuCl3(PPh3)3] with 1-(arylazo)naphthol ligands in benzene under reflux afford air-stable new organoruthenium(III) complexes with general composition [Ru(an-R)Cl(PPh3)2] (where, R = H, Cl, CH3, OCH3, OC2H5) in fairly good yield. The 1-(arylazo)naphtholate ligands behave as dianionic tridentate C, N, O donors and coordinates to ruthenium through phenolic oxygen, azo nitrogen and ortho carbon generate two five-membered chelate rings. The composition of the complexes have been established by analytical (elemental analysis and magnetic susceptibility measurement) and spectral (FT-IR, UV-Vis, EPR) methods. The complexes are paramagnetic (low-spin, d5) in nature and in dichloromethane solution show intense d-d transitions and ligand-to-metal charge transfer (LMCT) transitions in the visible region. The solution EPR spectrum of complex [Ru(an-CH3)Cl(PPh3)2] (3) in dichloromethane at 77 K shows rhombic distortion around the ruthenium ion with three different ‘g’ values (gx ≠ gy ≠ gz). The single crystal structure of the complex [Ru(an-OCH3)Cl(PPh3)2] (4) has been characterised by X-ray crystallography, indicates the presence of a distorted octahedral geometry in these complexes. All the complexes exhibit one quasi-reversible oxidative response in the range 0.60-0.79 V (RuIV/RuIII) and two quasi-reversible reductive responses (RuIII/RuII; RuII/RuI) within the range −0.50 to −0.62 V and −0.93 to −0.98 V respectively. The formal potential of all the couples correlate linearly with the Hammett constant of the para substituent in arylazo fragment of the 1-(arylazo)naphtholate ligand. Further, the catalytic efficiency of one of the ruthenium complexes (4) was determined for the transfer hydrogenation of ketones with an excellent yield up to 99% in the presence of isopropanol/KOH.  相似文献   

12.
New polypyridyl osmium(II) complexes [Os(κ3-tptz)(EPh3)2Cl]BF4 (E = P, 1; As, 2) with group 15 donor ligands are reported. Structural studies on the representative complex [Os(κ3-tptz)(PPh3)2Cl]BF4 revealed formation of helical racemates with sidewise stacking of right and left-handed anti-parallel helical strands. Salient structural features and DNA binding studies along with binding constant [6.6 × 103 M−1] and site size [0.12] of the complex 1 with calf thymus (ct) DNA by absorption spectroscopy are described.  相似文献   

13.
New cationic complexes [Ru(η5-C5H5)(EPh3)(L)]BF4 [L = pyridine-2-carbaldehyde azine (paa); E = P, 1; E = As, 2; E = Sb, 3] and κ1 bonded dppm complexes [Ru(η5-C5H5)(κ1-dppm)(L)]BF4 [L = paa 4; L = p-phenylene-bis(picoline)aldimine (pbp) 5] containing both group V donor and pyridyl-azine ligand are reported. The complexes were fully characterized by analytical and spectral studies. 31P NMR spectral studies suggested coordination of dppm in the complexes 4 and 5 in κ1-manner, which was further, confirmed by structural studies on the representative complex 4. Weak interaction studies revealed that inter- and intramolecular C-H?X (X = O, F, Cl, π) and π-π interactions in the complexes 1 and 4 lead to helical structures.  相似文献   

14.
Reactions of bis(pyridin-2-yl)ketone with tin tetrahalides, SnX4 (X = Cl or Br), or organotin trichlorides, RSnCl3 (R = Ph, Bu or CH2CH2CO2Me), in ROH (R = Me or Et) readily produces RObis(pyridin-2-yl)methanolato)tin complexes, [5: RO(py)2C(OSnX3)] (5: R,X = Me,Cl; Et,Cl; Et,Br) or [6: MeO(py)2C(OSnCl2R)] (R = Ph, Bu, CH2CH2CO2Me). In addition, halide exchange reaction between SnI4 and (5: R,X = Me,Cl) occurred to give (5: R,X = Me,I). The crystal structures of six tin(IV) derivatives indicated, in all cases, a monoanionic tridentate ligand, [RO(py)2C(O)-N,O,N], arranged in a fac manner about a distorted octahedral tin atom. The Sn–O and Sn–N bonds lengths do not show much variation amongst the six complexes despite the differences in the other ligands at tin.  相似文献   

15.
In this study selected bidentate (L2) and tridentate (L3) ligands were coordinated to the Re(I) or Tc(I) core [M(CO)2(NO)]2+ resulting in complexes of the general formula fac-[MX(L2)(CO)2(NO)] and fac-[M(L3)(CO)2(NO)] (M = Re or Tc; X = Br or Cl). The complexes were obtained directly from the reaction of [M(CO)2(NO)]2+ with the ligand or indirectly by first reacting the ligand with [M(CO)3]+ and subsequent nitrosylation with [NO][BF4] or [NO][HSO4]. Most of the reactions were performed with cold rhenium on a macroscopic level before the conditions were adapted to the n.c.a. level with technetium (99mTc). Chloride, bromide and nitrate were used as monodentate ligands, picolinic acid (PIC) as a bidentate ligand and histidine (HIS), iminodiacetic acid (IDA) and nitrilotriacetic acid (NTA) as tridentate ligands. We synthesised and describe the dinuclear complex [ReCl(μ-Cl)(CO)2(NO)]2 and the mononuclear complexes [NEt4][ReCl3(CO)2(NO)], [NEt4][ReBr3(CO)2(NO)], [ReBr(PIC)(CO)2(NO)], [NMe4][Re(NO3)3(CO)2(NO)], [Re(HIS)(CO)2(NO)][BF4], [99Tc(HIS)(CO)2(NO)][BF4], [99mTc(IDA)(CO)2 (NO)] and [99mTc(NTA)(CO)2(NO)]. The chemical and physical characteristics of the Re and Tc-dicarbonyl-nitrosyl complexes differ significantly from those of the corresponding tricarbonyl compounds.  相似文献   

16.
A series of ruthenium(III) complexes [RuX(EPh3)2L] (where X = Cl or Br; E = P or As; L = deprotonated dibasic tridentate ligand) were prepared by the reaction of [RuX3(EPh3)3] with Schiff bases (H2L1–H2L4). The ligands were prepared by the condensation of N-4 phenyl/methyl semicarbazide with o-vanillin/o-hydroxy acetophenone. The complexes were characterized by elemental, physico-chemical, and electrochemical methods. Catalytic studies of these complexes for the oxidation of alcohols and aryl–aryl coupling were carried out. Antimicrobial experiments were also carried out.  相似文献   

17.
Three copper(II) Schiff-base complexes, [Cu(L1)(H2O)](ClO4) (1), [Cu(L2)] (2) and [Cu(L3)] (3) have been synthesized and characterized [where HL1 = 1-(N-ortho-hydroxy-acetophenimine)-2-methyl-pyridine], H2L2 = N,N′-(2-hydroxy-propane-1,3-diyl)-bis-salicylideneimine and H2L3 = N,N′-(2,2-dimethyl-propane-1,3-diyl)-bis-salicylideneimine]. The structure of complex 1 has been determined by single crystal X-ray diffraction analysis. In complex 1, the copper(II) ion is coordinated to one oxygen atom and two nitrogen atoms of the tridentate Schiff-base ligand, HL1. The fourth coordination site of the central metal ion is occupied by the oxygen atom from a water molecule. All the complexes exhibit high catalytic activity in the oxidation reactions of a variety of olefins with tert-butyl-hydroperoxide in acetonitrile. The catalytic efficacy of the copper(II) complexes towards olefin oxidation reactions has been studied in different solvent media.  相似文献   

18.
A series of new hexa-coordinated ruthenium(II) carbonyl complexes of the type [RuCl(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3, AsPh3 or Py; L = 2′-hydroxychalcones) have been prepared by reacting [RuHCl(CO)(EPh3)2(B)] (E = P or As; B = PPh3, AsPh3 or Py) with 2′-hydroxychalcones in benzene under reflux. The new complexes have been characterized by analytical and spectral (IR, electronic, 1H, 31P and 13C NMR) data. Based on the above data, an octahedral structure has been assigned for all the complexes. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols into their corresponding aldehydes and ketones in the presence of N-methylmorpholine-N-oxide (NMO) as co-oxidant and also found efficient catalyst in the transfer hydrogenation of ketones. The antifungal properties of the complexes have also been examined and compared with standard Bavistin.  相似文献   

19.
The reactions of [RuHCl(CO)(B)(EPh3)2] (B = EPh3 or Py; E = P or As) and Schiff bases in 1:1 molar ratio led to the formation of [RuCl(CO)(EPh3)(B)(L)] (E = P or As; B = PPh3, AsPh3 or Py; L = Schiff base ligand). The new complexes have been characterized by analytical and spectroscopic (IR, electronic and 1H NMR) data. They have been assigned an octahedral structure. The new complexes were found to catalyse the transfer hydrogenation of ketones.  相似文献   

20.
A series of half-sandwich ruthenium(II) complexes containing κ3(N,N,N)-hydridotris(pyrazolyl)borate (κ3(N,N,N)-Tp) and the water-soluble phosphane 1,3,5-triaza-7-phosphaadamantane (PTA) [RuX{κ3(N,N,N)-Tp}(PPh3)2−n(PTA)n] (n = 2, X = Cl (1), n = 1, X = Cl (2), I (3), NCS (4), H (5)) and [Ru{κ3(N,N,N)-Tp}(PPh3)(PTA)L][PF6] (L = NCMe (6), PTA (7)) have been synthesized. Complexes containing 1-methyl-3,5-diaza-1-azonia-7-phosphaadamantane(m-PTA) triflate [RuCl{κ3(N,N,N)-Tp}(m-PTA)2][CF3SO3]2 (8) and [RuX{κ3(N,N,N)-Tp}(PPh3)(m-PTA)][CF3SO3] (X = Cl (9), H (10)) have been obtained by treatment, respectively, of complexes 1, 2 and 5 with methyl triflate. Single crystal X-ray diffraction analysis for complexes 1, 2 and 4 have been carried out. DNA binding properties by using a mobility shift assay and antimicrobial activity of selected complexes have been evaluated.  相似文献   

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