首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The X-ray structure is reported for the complex Cu2(medpco-2H)Cl2, (medpco = N,N′-bis-N,N-dimethylaminoethyl)pyridine-2,6-dicarboxamide 1-oxide. The complex is triclinic, , a=8.313(4), B=11.403(5), C=11.611(3) Å, =91.66(3), β=108.99(4), γ=109.60(3)° and Z=2. The deprotonated ligand (medpco-2H)2− acts as a binulceating ligand, producing an N-oxide-bridged complex. Each copper in Cu2(medpco-2H)Cl2 is five-coordinate, being coordinated by a bridging N-oxide oxygen, a deprotonated amide nitrogen, a tertiary amine nitrogen and two bridging chlorides. The complex does not exhibit significant magnetic interaction, and this may be the result of distortion of the bridging geometry from planarity. A range of other, apparently N-oxide-bridged, complexes of the type Cu2(medpco-2H)X2 is reported. The complex Cu2(medpco-2H)Br2·H2O is strongly antiferromagnetic, with magnetic data closely fitting the expected binuclear structure.  相似文献   

2.
Copper(I)/(II) complexes with the ligand 2-aminoethyl(2-pyridylmethyl)1,2-ethanediamine (apme, abbreviated as PDT in the literature as well) were prepared and characterized. Crystal structures of the copper(I) complexes, [Cu2(apme)2]X2 (1, 2; X = ClO4, CF3SO3), showed that they are dinuclear, in contrast to the trigonal bipyramidal copper(II) complexes [Cu(apme)Cl]BPh4 (3) and [Cu(apme)(DMF)](BPh4)2 (4). 1 and 2 could be investigated in solution by NMR spectroscopy and 3 and 4 by cyclovoltammetry. From the results of these studies it is clear that in solution equilibria between the dinuclear complexes 1/2 and another species exist, most likely the monomeric [Cu(apme)CH3CN]+. Time-resolved UV/vis spectra at low temperatures allowed the spectroscopic detection of dioxygen adduct complexes as reactive intermediates during the oxidation of 1/2 with dioxygen that seem to play an important role in copper enzymes such as peptidylglycine--hydroxylating monooxygenase (PHM).  相似文献   

3.
The complexes [Pt(NH3)(pmbah)Cl2], [Pt(NH3)(pcbah)Cl2], [Pt(pmbah2X2] and [Pt(pcbah)2X2] (pmbah = 4-methoxybenzoicacid hydrazide, pcbah = 4-chlorobenzoic acid hydrazide; X = Cl, Br, I) have been synthesized and characterized by elemental analysis, electric conductivity, 1H NMR, IR, and electronic spectra. A cis-square planar structure with hydrazide ligands coordinated via the NH2 groups has been proposed for these compounds. The complexes, but not the free ligands, have shown a strong growth inhibitory effect in Friend leukemia cells in vitro, most of which are more active than cisplatin.  相似文献   

4.
Monomeric complexes [Cu(LL)(L′)(NO3)2] (where LL is 2,2′-bipyridine or 1,10-phenanthroline and L′ is 1-methylimidazole) and dimeric complexes [Cu2(LL)2(L″)]NO3 (where L″ is an anion of imidazole or 2-methylimidazole) have been synthesized. These complexes show a d-d transition in the range of 600 to 710 nm. The infrared spectra of monomeric complexes show that the NO3 is coordinated to copper as a monodentate ligand through an oxygen atom. The ESR spectra of monomeric complexes indicate that the ligands are bonded in axial environment around copper (square pyramidal geometry) with three nitrogen donors occupying an equatorial plane. The ESR spectra of dimeric complexes show a broad signal at about G = 2 with an additional weak signal at about G = 4. This suggests that two copper atoms are in close proximity of < 7 Å. The ESR studies reveal that the formation of imidazolate-bridged binuclear copper(II) complexes from [Cu(LL)(L′)(NO3)2] and imidazole is pH dependent with apparent pKa values of 8.25 to 8.30. The superoxide dismutase activity of ICu(phen)(L′)(NO3)2], [Cu(bipy)(L′)(NO3)2], and [Cu2(bipy)2(L′)2(L″)]NO3 has been measured and the latter two complexes show better activity than the former complex.  相似文献   

5.
The preparation of N-, S- and O-donor ligand adducts with CuX+(HX=6-methyl-2-formylpyridinethiosemicarbazone (6HL); 2-formylpyridine-2-methylthiosemicarbazone (2′L); 2-formylpyridine-4′-methylthiosemicarbazone (4′HL)) is described. The N-donors, 2,2′-bipyridyl (bipy), 4-dimethylaminopyridine (dmap) give the complexes [Cu(6L)(bipy)]PF6, [Cu(6L)(bipy)]Cl·5H2O, [Cu(4′L)(bipy)]PF6, [Cu(6L)(dmap)2]PF6·2.5 H2O and [Cu(4′L)(dmap)2]PF6·H2O which have been characterized by physical and spectroscopic techniques. Pentafluorothiophenolate (pftp) gives S-donor complexes [CuX(pftp)] (X=6L and 4′L) and thiolato co-ordination is proposed on the basis of spectroscopic evidence. Paratritylphenolate (ptp) and HPO2−4 give O-donor complexes [Cu(6L)(ptp)], [Cu(4′L)(ptp)], [{Cu(6L)}2HPO4]·4H2O, and [{Cu(4L)}2HPO4]·5H2O which have been characterized by physical and spectroscopic techniques, as have the precursor complexes [Cu(6L)(CH3COO)]·H2O, [Cu(4′L)(CH3COO)], Cu(6HL)(CF3COO)](CF3COO)·0.5H2O, [Cu(4′HL)(CF3COO)](CF3COO), [Cu(2′L)Cl2] and [Cu(2′L)(NO3)2]. Protonation constants for the ligands and some of their complexes have been determined. 2-Formylpyridinethiosemicarbazone (HL) complexes of silver, gold, zinc, mercury, cadmium and lead are also discussed. Cytotoxicity against the human tumor cell line HCT-8 and antiviral data for selected compounds are presented.  相似文献   

6.
N1-Benzylidene-pyridine carboxamidrazones and their metal conjugates have emerged as a new class of potential antimycobacterial agents. Nine such carboxamidrazone analogs (L1–L9) along with their Cu(II) (MC1–MC9) and Fe(III) (MC10–MC18) complexes were synthesized. Single crystal X-ray structures of copper complexes MC1 and MC5 were determined which suggest slightly distorted square planer geometries for copper complexes and octahedral geometries for ferric compounds. All compounds were evaluated for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv. The results show 32–64-fold enhancement in antitubercular activity upon copper complexation.  相似文献   

7.
With exposure to trace amounts of air and moisture, the Cr2(II, II) complex Cr2(μ-3,5Cl2-form)4, where 3,5Cl2-form is [(3,5-Cl2C6H3)NC(H)N(3,5-Cl2C6H3)], undergoes an oxidative addition reaction. Structural information from the X-ray crystal structure of the edge-sharing bioctahedral (ESBO) Cr2(III, III) product Cr2(μ-OH)2(μ-3,5Cl2-form)22-3,5Cl2-form)2 (1) indicates 1 has a significantly longer Cr–Cr distance [2.732(2) Å] than Cr2(μ-3,5Cl2-form)4 [1.9162(10) Å], but the shortest Cr–Cr distance in an ESBO Cr2(III, III) complex recorded to date.  相似文献   

8.
The formation of complexes between copper(II) halides and 2,2′-dipyridylamine (dipyam) has been studied systematically. Only complexes with a 1:1 and 1:2 metal-to-ligand ratio are formed. Some mixed chloro–iodide and halide–PF6 compounds have also been isolated. The X-ray diffraction structures of the [Cu(dipyam)2Br2] · 2H2O (I) and the [Cu(dipyam)2Cl]2I2 · 2CH3CN (II) complexes are reported. I is a rare example of an octahedral coordination among the copper(II) halide complexes of dipyam. The two bromo atoms, which occupy the apical positions, are H-bonded to the water molecules of crystallization. II is a dimer, where each copper forms a cationic chloro-complex of approximately trigonal bipyramidal geometry, the dimerization being due to hydrogen bonds formed by the NH group of one of the two dipyams coordinated to each metal atom with the chlorine atom of the centrosymmetric cationic complex. The iodide anions are hydrogen-bonded to the NH groups of the dipyams not involved in the dimerization.  相似文献   

9.
The complexes [(bpy)2Ru(dpp)]Cl2, [(phen)2Ru(dpp)]Cl2, and [(Ph2phen)2Ru(dpp)]Cl2 (where dpp = 2,3-bis(2-pyridyl)pyrazine, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline, Ph2phen = 4,7-diphenyl-1,10-phenanthroline) have been investigated and found to photocleave DNA via an oxygen-mediated pathway. These light absorbing complexes possess intense metal-to-ligand charge transfer (MLCT) transitions in the visible region of the spectrum. The [(TL)2Ru(dpp)]2+ systems populate 3MLCT states after visible light excitation, giving rise to emissions in aqueous solution centered at 692, 690, and 698 nm for TL = bpy, phen, and Ph2phen respectively. The 3MLCT states and emissions are quenched by O2, producing a reactive oxygen species. These complexes photocleave DNA with varying efficiencies, [(Ph2phen)2Ru(dpp)]2+ > [(phen)2Ru(dpp)]2+ > [(bpy)2Ru(dpp)]2+. The presence of the polyazine bridging ligand will allow these chromophores to be incorporated into larger supramolecular assemblies.  相似文献   

10.
In vitro copper (II) complex presents antimitotic effects. In this work, we have studied the in vivo seasonal toxic effects of copper (II), ligand (H2L) and the complex [Cu(H2L)(H2O)2]Cl2·4H2O in male Swiss mice. During spring, an i.p. injection of CuCl2 in aqueous NaCl (9 g·l-1) up to 0.05 µmol·kg-1 b.w. (body weight) killed 60% of the rodents after 6 days. LD100 was up to 0.3 µmol·kg-1; H2L was well tolerated, while the complex was 30% lethal with 50 µmol·kg-1. In autumn, mice were less sensitive to CuCl2, and both ligand and complex were equally tolerated and this leads to the conclusion that, in vivo, chronotoxicities of copper (II) and complex in NaCl aqueous solutions are quite different in spring and autumn seasons.  相似文献   

11.
The reactions of arene–metal complexes (arene = p-cymene, benzene or pentamethylcyclopentadienyl, metal = Ru, Rh or Os), including 1,3,5-triaza-7-phosphatricyclo-[3.3.1.1]decanephosphine (pta) and chloro co-ligands, with 9-methylguanine, adenine, and a series of nucleosides were studied in water to ascertain the binding modes. The products were characterized by NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). Tandem mass spectrometry was found to provide excellent information on preferential binding sites. In general, the N7 position on guanine (the most basic site) was found to be the preferred donor atom for coordination to the metal complexes. The X-ray structures of the precursor complexes, [(η5-C10H15)RhCl(pta-Me)2]Cl2, [(η6-C10H14)OsCl(pta)2]Cl, and [(η6-C6H6)OsCl2(CH3CN)], are also reported.  相似文献   

12.
Two new dicyanamide bridged 1D polynuclear copper(II) complexes [Cu(L1){μ1,5-N(CN)2}]n (1) [L1H = C6H5C(O)NHNC(CH3)C5H4N] and [Cu(L2){μ1,5-N(CN)2}]n (2) [L2H=C6H5C(O)CHC(CH3)NCH2CH2N(CH3)2] have been synthesised and structures of both the complexes and their crystal packing arrangements have been established by X-ray crystallography. For complex 1, a tridentate hydrazone ligand (L1H) obtained by the condensation of benzhydrazide and 2-acetylpyridine is used, whereas a tridentate Schiff base (L2H) derived from benzoylacetone and 2-dimethylaminoethylamine is employed for the preparation of complex 2. Variable temperature magnetic susceptibility measurement studies indicate there are weak antiferromagnetic interactions with J values −0.10 and −1.41 cm−1 for 1 and 2, respectively.  相似文献   

13.
The first 1:2 metal complexes of 2-(2′-pyridyl)quinoxaline (L) have been isolated. The physical and spectroscopic characteristics of the compounds [MCl2L2] (M = Ni, Cu, Cd) and [CuIL2](PF6) are described. The structure of the copper(I) complex has been determined by X-ray diffraction methods. Crystals are orthorhombic, space group Pcnb with A = 11.014(2), B = 12.886(2), C = 17.806(4) Å, V = 2527.1(9) Å3 and Z = 4. Refinement of the structure gave a final R factor of 0.046 (Rw = 0.041) for 814 unique reflections having I > 2.0σ(I). The ligand L acts as a bidentate chelate, the ligated atoms being the pyridine nitrogen and the nearest quinoxaline nitrogen. The structure of [CuL2]+ consists of a distorted tetrahedral arrangement around the copper(I) atom with Cu---N bond lengths of 2.023(6) and 2.059(5) Å and the N---Cu---N angle of the chelating ligand equal to 80.6(2)°. A monomeric trans pseudo-octahedral stereochemistry is assigned for the [MCl2L2] complexes.  相似文献   

14.
Antitumor active [1,2-bis(4-fluorophenyl)ethylenediamine]platinum(II) diastereoisomers containing acetic acid derivatives as ‘leaving groups’ (acetate: meso/rac-4F-Pt(Ac)2; monochloroacetate: meso/rac-4F-Pt(ClAc)2; dichloroacetate: meso/rac-4F-Pt(Cl2Ac)2; trichloroacetate: meso/rac-4F-Pt(Cl3Ac)2; glycolate: meso/rac-4F-Pt(OHAc)2; phenylacetate: meso/rac-4F-Pt(PhAc)2) were synthesized and characterized by IR and 1H NMR spectroscopy. In all complexes except meso/rac-4F-Pt(PhAc)2, which exist as [meso/rac-4F-PtPhAc]+PhAc, both carboxylic acid residues are coordinated to platinum. Kinetic studies on the reaction behavior of the title compounds with nucleophiles were performed by using iodide as nucleophile. The studies show that the new complexes react with nucleophiles predominantly via the ‘solvent path’ (i.e. via the reactive intermediates = Pt(X)(OH2)+ and =Pt(OH2)22+. Therefore the rates of reactions in which the reactive species are formed affect the antitumor activity of the complexes as well as their inactivation by bionucleophiles during the transport to the tumor. The extent of accumulation in the tumor cell, too, influences the antitumor activity of a complex. The rate constants are discussed in view of the activities of the respective complexes on the human MCF-7 breast cancer cell line. From the title compounds the Cl2Ac and Cl3Ac derivatives do not come close to the standard cisplatin, neither in chemical reactivity nor in biological activity. Meso/rac-4F-Pt(Ac)2 and meso/rac-4F-Pt(ClAc)2, respectively, show similar hydrolysis rates but lower antitumor activities than cisplatin, presumably due to a reduced drug uptake by the tumor cell. Meso/rac-4F-Pt(PhAc)2 compare well with their standard carboplatin in respect to both properties. Other than the remaining, poorly water soluble title compounds, meso/rac-4F-Pt(OHAc)2 equal their standard cisplatin in terms of water solubility and antitumor activity rac-4F-Pt(OHAc)2 > meso-4F--Pt(OHAc)2). However, they are markedly faster hydrolyzed than cisplatin. By use of rac-4F-Pt(Ac)2 as an example it was confirmed that, in contrast to the parent compound rac-4F-PtCl2, the new complex type is also active under in vivo conditions owing to its markedly lower reactivity (mainly due to the lack of a direct substitution by strong nucleophiles), which entails a reduced inactivation of the drug on its way to the tumor. The in vitro testing on tumor cell lines combined with the evaluation of the water solubility and with kinetic studies on the reaction with nucleophiles is a useful method for the preselection of potent platinum complexes deserving further thorough in vitro and in vivo investigations.  相似文献   

15.
Two novel adducts of Cu(Clqo)2 (Clqo = 4-chloro-1,2-benzoquinone 2-oximato),i.e. K[Cu(Clqo)2(NCO)] (1) and (Bu4N)2[Cu(Clqo)2(NCO)]OCN (2) have been isolated and characterized by vibrational and electronic spectra. In both compounds the copper(II) atom is pentacoordinated; in fact the X-ray crystal structure determination of complex2 showed that only one of the two cyanato groups is N-bonded of the CuII center, while the other one is non-coordinated.  相似文献   

16.
The reaction of Cu(II) ions with a sodium salt of new Schiff base ligand NaL1, sodium N-2-methyl pyridine-2-imine benzoate, in alkaline medium produced an imine bond coupled ligand and a novel complex, Na2[Cu(L3)2], L3 = 2,5-di(2-benzoic acid)-4-(2-pyridine)-1-(2-methyl-2-pyridine)-imidazolidine. When the reduced form of the sodium salt of the Schiff base ligand, NaL2, is employed, a simple hexacoordinated copper(II) complex, [Cu(L2)2], [L2] = bis(N-(2-methylpyridine)-2-aminomethylbenzoate), was isolated. The compounds were characterized by spectroscopic methods and the molecular structures of [Cu(L2)2] and Na2[Cu(L3)2] were determined by single-crystal X-ray diffraction methods. Reaction mechanism for the synthesis of, Na2[Cu(L3)2], copper(II) promoted imine bond coupling is proposed and discussed. The redox behavior of [Cu(L2)2] and Na2[Cu(L3)2], studied using cyclic voltammetry and electron paramagnetic resonance spectroscopic methods, are also discussed.  相似文献   

17.
Copper(II), nickel(II) and cobalt(II) complexes of the aspirin metabolite salicylglycine (H2L), of stoichiometry M(HL)2·solvate, have been prepared and characterised. In these complexes salicylglycinate is coordinated to the metal via its carboxylato group and possibly also its amide oxygen in the copper(II) complex. Under basic conditions copper(II) forms the complex Cu(LH−1)·2H2O·MeOH, in which the ligand is coordinated to the metal via its carboxylate and phenolate oxygen atoms and the deprotonated peptide nitrogen atom.  相似文献   

18.
The products formed in reactions of the square-planar platinum(II) anticancer complexes, [Pt(en)Cl2] and [Pt(R,R-dach)Cl2] where en = ethylenediamine and dach = diaminocyclohexane, with trypanothione, a glutathione analogue found in some parasites, and octreotide, a synthetic analogue of the hormone somatostatin, have been investigated. Mononuclear and binuclear platinum adducts were formed in reactions of the cyclic disulfides in their oxidised and reduced forms, and were analysed by UV–visible spectroscopy and liquid chromatography–mass spectrometry (LC–MS). NMR and molecular modelling studies were carried out on the mononuclear adducts.  相似文献   

19.
In dimethylformamide superoxide ion forms a l:l adduct with tctrakis (2.6-dichlorophenyl) porphinatoiron, (Cl8 TPP)FeOO-, as well as with its manganese analogue, (Cl8 TPP)MnOO-. On the basis of their electrochemical, spectroscopic, and magnetic properties these adducts have a metal-oxygen covalent bond (PorM-OO-), oxygen-centered redox chemistry. and reactivities that are similar to the hydroperoxide ion (HOO-). Addition of -OH to a solution of PorFe and O2 results in the formation of PorFe(OH)(OO-), which can be electrochemically oxidized to PorFeOH plus O2 (-0.2 V vs SCE). Addition of protons to the PorM-OO- adducts promotes their rapid decomposition to PorM, HOOH. and O2. This chemistry provides insight to the reactions of biological superoxide and superoxide dismutases.  相似文献   

20.
Two new copper(II) complexes, Cu(L1)(ClO4)2 (1), {[(μ-oxalate)Cu(L1)] · 5H2O}n (2), and a zinc(II) complex, {[(μ-oxalate)Zn(L2)] · 3H2O · 0.5DMF}n (3) (L = 3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,01.18,07.12]docosane), have been synthesized and characterized by X-ray crystallography. In 1, the ligand conformation is planar, and the octahedral coordination about the copper(II) ion is completed by weakly interacting ions. In 2 and 3, bridging oxalate ligands coordinate to copper(II) or zinc(II) ions in an unusually twisted bis-monodentate (trans-1,1′-bicoordination) mode.

The rigidity and steric hindrance of macrocycles L1 and L2 by the introduction of two cyclohexane rings and methyl groups on a cyclam (1,4,8,11-tetraazacyclotetradecane) skeleton cause the bridging oxalate ligands to adopt such unusual geometries in 2 and 3.  相似文献   


设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号