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1.
Salicylaldehyde-4-methylthiosemicarbazone (H2MTSali) has been prepared via the condensation reaction of 4-methyl-3-thiosemicarbazide and salicylaldehyde. Four new mixed-ligand copper(II) and nickel(II) complexes with a general formula [M(MTSali)L] (M = Cu2+ or Ni2+; L = co-ligand) were synthesized, where L is either imidazole (im) or benzimidazole (bzim). The Schiff base and its mixed-ligand complexes were characterized by IR and UV/Vis spectroscopy, and the complexes by molar conductivity and magnetic susceptibility measurements. The spectroscopic data indicated that the Schiff base behaves as a tridentate ONS donor ligand coordinating via the phenoxide-oxygen, azomethine-nitrogen, and thiolate-sulphur atoms. Magnetic data indicate a square planar environment for the nickel(II) complexes while molar conductance values indicate that the metal complexes are essentially non-electrolytes in DMSO solution. X-ray crystallography shows Cu(MTSali)bzim (1) and Ni(MTSali)bzim (3) to be isostructural, with the metal(II) ions being coordinated by a N2OS donor set that defines an approximate square planar geometry; in both cases, the benzimidazole is splayed with respect to the coordination plane. The copper(II) complexes were active against MDA-MB-231 and MCF-7 breast cancer cell lines, more so than H2MTSali, whereas the nickel(II) complexes were inactive.  相似文献   

2.
Reaction of Na4TCM (1) (H4TCM = tetra[4-(carboxyphenyl)oxamethyl]methane) with [Cu(CHA)](ClO4)2 (2)(CHA = 1,3,6,8,11,14-hexaaz atricyclo[12.2.1.1.8,11] octadecane) in a DMF-water mixture yields [Cu(CHA)]2[TCM] (3). Structural analysis of [Cu(CHA)]2[TCM]·11H2O (3·11H2O) by single crystal X-ray diffraction reveals strong copper-oxygen bonds between two complex cations and the tetraanion leading to a 3D coordination network (zwitterionic structure), consolidated through additional NH...O=C hydrogen bonding within the cation/anion association. The resulting coordination geometry around a copper atom is a distorted square pyramidal with an oxygen atom of the anionic ligand in the apical position. A 3D supramolecular network is developed in the crystal based only on NH...OC hydrogen bonds between the macrocyclic metallic tecton and the carboxylate groups of neighboring 3D coordinated (zwitterionic) moieties. The pseudotetrahedral TCM4? tetraanionic ligand induces a diamondoid architecture formed of large distorted adamantanoid cages.   相似文献   

3.
NOO-type tridentate Schiff base, N-salicylidene-2-aminobenzoic acid, (H2L), and its ternary Cu (II) complex containing H2L Schiff base and 4,7-dimethyl-1,10-phenanthroline (4,7-dmphen), [Cu(4,7-dmphen)(H2L)]27H2O, have been synthesized and characterized by CHN analysis, ESI-MS, FTIR, and single-crystal X-ray diffraction techniques. The interaction of alone H2L Schiff base ligand and ternary Cu (II) complex with biomacramolecules {calf thymus DNA (CT-DNA) and bovine serum albumin (BSA)} has been investigated by electronic absorption and fluorescence spectroscopy. The experimental results indicate that H2L Schiff base ligand and ternary Cu (II) complex bind to CT-DNA by means of a moderate intercalation mode. Furthermore, the fluorescence quenching mechanism between H2L Schiff base ligand and ternary Cu (II) complex with BSA possesses a static quenching process. Radical scavenging activity of H2L Schiff base ligand and ternary Cu (II) complex was measured in terms of EC50, using the DPPH and H2O2 methods. Biomacromolecule interactions and scavenging activity studies revealed that ternary Cu (II) complex yielded better results than H2L Schiff base ligand alone.  相似文献   

4.
The new trinuclear complex [Cu2(μ-L)2CuCl2] has been synthesized and characterized by elemental analysis, IR, UV-Vis and X-ray spectroscopy, where L is a dianionic tetradentate Schiff base ligand with N2O2 donor atoms. The molecular structure of [Cu2(μ-L)2CuCl2] was determined by X-ray crystallography. In the complex, the most remarkable aspect of the trinuclear complex is that it adopts a bent structure for the three copper atoms, with a Cu1Cu3Cu2 intramolecular angle of approximately 90.62(2)°. All three copper atoms are five coordinate, with a slightly distorted square pyramidal geometry. In the two terminals moieties, the basal plane of the square pyramidal is formed by two oxygen atoms and two nitrogen atoms of the Schiff base ligand, and the apical position at the Cu atom is occupied by the bridging Cl1 anion. The Cu1Cl1Cu2 angle is 110.51(5)°. The central copper atom also has a five-coordinate, slightly distorted square pyramidal geometry, with four phenolato oxygens belonging to the Schiff base ligands from Cu(salpn) units describing the square planar base and the Cl anions being apical. The optimized structure of the complex has been studied using the B3LYP/6-31G(d)/LanL2TZf level of theory. The calculation shows that all the copper atoms are five coordinate with distorted square pyramidal structures, which is consistent with experimental data.  相似文献   

5.
Mono- and trinuclear copper(II) complexes with 2-[1-(2-dimethylamino-ethylamino)-ethyl]-phenol (HL) have been synthesized and structurally characterized. The mononuclear complex [Cu(L)(H2O)(ONO2)] (1) crystallizes in monoclinic space group P21 /n with a square pyramidal Cu(II) center coordinated by the tridentate Schiff base (L) and a water ligand in the equatorial plane and an oxygen atom from nitrate in the axial position. The trinuclear complex [(CuL)33-OH)](ClO4)2·H2O (2) crystallizes in hexagonal space group P63; all three copper atoms are five-coordinate with square pyramidal geometries. The interactions of these complexes with calf-thymus DNA have been investigated using absorption spectrophotometry. The mononuclear complex binds more strongly than the trinuclear complex. The DNA cleavage activity of these complexes has been studied on double-stranded pBR 322 plasmid DNA by gel electrophoresis experiments in the absence and in the presence of added oxidant (H2O2). The trinuclear complex cleaves DNA more efficiently than the mononuclear complex in the presence of H2O2.  相似文献   

6.
Two mononuclear Cu(II) complexes, [Cu(L1H2)](ClO4)1.25Cl0.75·1.25H2O (1) and [Cu(L2H2)](ClO4)2 (2), of the pyridoxal Schiff base ligands N,N′-dipyridoxylethylenediimine (L1H2) and N,N′-dipyridoxyl-1,3-propanediimine (L2H2) are reported. X-ray crystal structures of both complexes are also reported. In both complexes the pyridoxal nitrogen atoms remain protonated. In the solid state, the tetradentate Schiff base ligand is virtually planar in 1, while in 2 the ligand conformation is like an inverted umbrella. In cyclic voltammetry experiments it is found that in these complexes the Cu(III) and Cu(I) states are more easily accessible than in their salen type analogs. The pyridoxal Schiff base complexes are also found to be resistant to oxidative electro-polymerization, unlike their corresponding salicyl aldehyde Schiff base complexes.  相似文献   

7.
In this research, we prepared a new series of the Cu(II) (1) and Ni(II) (2) metal complexes of a tridentate Schiff base ligand, (E)-2-(5-bromo-2-hydroxybenzylideneamino) phenol (H2L). These complexes were characterized by elemental analysis, FT-IR, UV–Vis, and 1H-NMR spectroscopy. The crystal structures of (1) and (2) were determined by X-ray diffraction studies. The single crystal X-ray diffraction analyses revealed that copper(II) cation is five-coordinated and the coordination polyhedron is a slightly distorted square pyramid. Nickel(II), on the other hand, is four-coordinated, and has a regular, square planar geometry. Further discussed were the electrochemical reduction of these complexes. We also analyzed the nature of the metal–ligand bond in the complexes through NBO and EDA analysis. Besides, vibrational sample magnetometer (VSM) revealed complex (1) was ferromagnetic.  相似文献   

8.
A new Schiff base complex [Ni(H2L1)(NO3)](NO3) (1) (H2L1 = 3-[N,N′-bis-2-(5-bromo-3-(morpholinomethyl) salicylideneamino) ethyl amine]) was synthesized from reaction of the ditopic ligand H2L1 with Ni(NO3)2 in anhydrous MeOH. Complex 1 is stable in the solid state, but prone to hydrolysis. Recrystallization of 1 from wet MeOH led to the isolation of a novel unsymmetrical complex [Ni(HL2)(NO3)](NO3) (2) (HL2 = 2-[(2-(2-aminoethylamino) ethylimino) ethyl)-5-bromo-3-(morpholino methyl) salicylidene amine]). X-ray single-crystal analysis of complex 2 showed that complex 1 had undergone partial decomposition of one imine bond. In contrast, the Schiff base complex [Ni(HL3)](NO3) (3) (H2L3 = N,N′-bis(5-methyl-salicylidene) diethylenetriamine) was stable in wet methanol, and the single-crystal structure of 3 showed that the Ni(II) center was coordinated in an unsymmetrical square planar geometry. Density functional theory calculations were performed in order to obtain a geometry-optimized model of complex 1, in which the Ni(II) center was coordinated in a similar manner as that in complex 3. The thermodynamic parameters were calculated, in order to rationalize the difference in hydrolytic reactivity between complexes 1 and 3.  相似文献   

9.
A bis-Schiff base N,N'-bis(5-methylsalicylidene)ethane-1,2-diamine (H2L) was prepared and characterized by elemental analysis, 1H NMR and 13C NMR spectra, MS, and single crystal X-ray diffraction (CIF file CCDC no. 1022761 (H2L)). Reaction of the Schiff base with copper bromide and sodium dicyanoamide in methanol gave a novel bromido-, phenolato-, and dicyanoamido-cobridged polymeric copper(II) complex, ({Cu2LBr[N(CN)2]}2)n (I). Structure of complex I was characterized by elemental analysis and single crystal X-ray diffraction (CIF file CCDC no. 1022762 (I)). The smallest repeat unit of complex I is a dicyanoamide bridged tetranuclear copper(II) complex moiety, {Cu2LBr[N(CN)2]}2, in which there possesses a crystallographic inversion symmetry. The tetranuclear moieties are further linked through Br atoms, forming a zigzag chain. The chains are further linked by dicyanoamide ligands, forming a 2D network. One Cu atom in complex I is coordinated by two N and two O atoms of the Schiff base ligand and one Br atom, forming square pyramidal geometry. The other Cu atom is coordinated by two N atoms of the Schiff base ligand, two N atoms of dicyanoamide ligands, and one Br atom, forming square pyramidal geometry. The bromido-, phenolato-, and dicyanoamido-cobridged Cu···Cu distances are 4.823(2), 2.955(1), and 7.121(3) Å, respectively. The [Cu2L] units are linked by the bridging groups, to form 2D chains along the xy plane.  相似文献   

10.
9-Bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-ylhydrazine was reacted with 2-acetylpyridine to give a Schiff base as a potential tridentate ligand. The reaction of this ligand with gallium chloride afforded complexes of 1:1 and 2:1 stoichiometry. The results of X-ray diffraction studies of the ligand and both gallium complexes are reported and compared with the data for a related gallium complex with a Schiff base obtained from 9-bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-ylhydrazine and 2-hydroxybenzaldehyde.   相似文献   

11.
The synthesis of the [Cu(H2L)](NO3)2 complex (I) and of a mixed-valent complex [Cu(H2L)Cl]2[CuCl2]Cl·0.5H2O (II), where L is chiral bis(menthane) propylenediaminodioxime. According to the data of single-crystal X-ray diffraction analysis, compounds I and II have ionic structures. In complex cations, the Cu2+ ion coordinates four N atoms of tetradentate chelate ligand, namely, the H2L molecule. The coordination surrounding of the Cu atom in I is a distorted square CuN4, while in II, it is a distorted square pyramid CuN4Cl. The complex anion [CuCl2]? in II has linear structure. The mutual arrangement of oxime groups in H2L corresponds to amphi-configuration of a ligand and therefore, intramolecular hydrogen bond O...H-O are formed in H2L. The complex cations in compound II are joined in dimers through hydrogen bonds Cl...H-O. The values μeff for I and II are equal to 1.82 and 2.82 μB, respectively.  相似文献   

12.
Reaction of a macrocyclic copper(II) complex [Cu(L)](ClO4)2 · 3H2O (I) (L = 1,3,10,12,16,19-hexaazatetracyclotetracosane) with a hexapod carboxylate ligand H6TTHA (H6TTHA = 1,3,5-triazine-2,4,6-triamine hexaacetic acid) and a tripod carboxylate ligand H3TATB (H3TATB = 4,4′,4″-S-triazine-2,4,6-triyl-tribenzoic acid) yielded two mononuclear copper(II) complexes [Cu(L)][H4TTHA] · 4H2O (II) and [Cu(L)][HTATB] · 4H2O (III). The complexes I–III have been structurally characterized. The crystal structures of complexes II and III show the copper(II) ion has a distorted pentacoordinate square-pyramidal geometry with two secondary and two tertiary amines from the macrocyclic complex [Cu(L)]2+ and one oxygen atom from the carboxylate ligand group at the axial position. The UV-Vis spectra are utilized to discuss the hydrolysis of the complex II.  相似文献   

13.
A Schiff base (L) is prepared by condensation of cuminaldehyde and L-histidine, and characterized by elemental analysis, IR, UV-Vis, 1H-NMR, 13C-NMR, and mass spectra. Co(II), Ni(II), Cu(II), and Zn(II) complexes of this Schiff-base ligand are synthesized and characterized by elemental analysis, molar conductance, mass, IR, electronic spectra, magnetic moment, electron spin resonance (ESR), CV, TG/DTA, powder XRD, and SEM. The conductance data indicate that all the complexes are 1 : 1 electrolytes. IR data reveal that the Schiff base is a tridentate monobasic donor, coordinating through azomethine nitrogen, imidazole nitrogen, and carboxylato oxygen. The electronic spectral data and magnetic measurements suggest that Co(II) and Ni(II) complexes are tetrahedral, while Cu(II) complex has distorted square planar geometry. XRD and SEM show that Co(II), Cu(II), and Zn(II) complexes have crystalline nature, while the Ni(II) complex is amorphous and the particles are in nanocrystalline phase. The in vitro biological activities of the synthesized compounds were tested against the bacterial species, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus; and fungal species, Aspergillus niger, Aspergillus flavus, and Candida albicans by the disc diffusion method. The biological study indicates that complexes exhibit more activity than the ligand. The nuclease activity of the ligand and its complexes are assayed on CT DNA using gel electrophoresis in the presence and the absence of H2O2. The Cu(II) complex shows increased nuclease activity in the presence of an oxidant when compared to the ligand, Co(II) and Ni(II) complexes.  相似文献   

14.
The Schiff base ligand, HL · 0.5C2H5OH (HL = methyl N-[(4-chlorophenyl)(3-methyl-5-oxo-1-phenyl-4,5-dihydro-1H-pyrazol-4-ylindene)methyl]valine), was derived from condensation of 1-phenyl-3-methyl-4-(p-chlorbenzyl)-5-pyrazolone with L-valine methyl ester in a 1: 1 molar ratio in methanol, ether and isopropanol solution. Reaction of ligand with Co(ClO4)2 · 6H2O (in a 2: 1 molar ratio) in methanol solution afforded a mononuclear cobalt(II) complex, [Co(L)2] (I). Molecular structures of HL · 0.5C2H5OH and complex I were characterized by elemental analysis, IR and single crystal X-ray diffraction analysis. The enamine-keto form of the ligand has turned to imine form in complex I. Each Co(II) center in complex I is in a octahedral N2O4 coordination sphere. Both the Schiff base ligand and its Co(II) complex have been tested in vitro with agar dilution method to evaluate their antibacterial activity against bacteria Escherichia coli and Staphylococcus aureus. It has been found that they have higher activity against Escherichia coli than Staphylococcus aureus, and complex I has higher activity than HL · 0.5C2H5OH against the same bacteria.  相似文献   

15.
A binuclear copper complex [{Cu(L)2}2], C68H48Cu2N4O12C (where L is 4-methyl-7-(salicylideneamino)coumarin), has been synthesized and characterized using elemental analysis, molar conductance measurements, and infrared, ultraviolet and ESR spectrosopy. The molecular structure of title compound, determined by single-crystal X-ray diffraction studies, reveals that the two symmetric Cu(L)2 units are associated into a dimer by rather long Cu...O bonds. The Cu(II) ions are bridged via the phenolic oxygen of one of the monomers and have distorted trigonal bipyramidal conformation geometry. Within each monomer the two methylsubstituted coumarin skeletons are trans to one another, but adopt a parallel arrangement with respect to the other monomer. Only half of the complex molecule can be found in the asymmetric unit, Z′ = 0.5, the other half is generated by the symmetry centre.   相似文献   

16.
Two novel complexes, [La(HL)(H2O)2NO3] · NO3 · H2O and [Gd(HL)(H2O)2NO3] · NO3 · H2O, where HL is a Schiff base derived from o-vanillin and lysine, have been synthesized and characterized by elemental analysis, conductivity measurements, IR, 1H NMR and thermogravimetric analyses (TGA). The Schiff base ligand behaves as a tetradentate, coordinating through azomethine nitrogen, phenolic oxygen and two carboxylic oxygen atoms. The interaction of these complexes with calf thymus DNA (CT-DNA) was also investigated by spectrometric titration and viscometric measurements. The faint hypochromism of the complexes in the absorption spectra, the remarkable reduction of fluorescence intensity of ethidium bromide (EB) bound DNA, together with a small decrease in the viscosity of the DNA suggest that a partial intercalation may be the preferred binding mode between these two complexes and DNA. The antibacterial activity testing revealed that the complexes and their precursor Schiff base show a weak to moderate activity against Bacillus subtilis, Staphylococcus aureus and Escherichia coli.   相似文献   

17.
The single crystal X-ray structures and the spectroscopic properties of complexes of monensic acid (C36H62O11·H2O) with toxic metal ions of Cd(II) and Hg(II) are discussed. The cadmium(II) complex (1) is of composition [Cd(C36H61O11)2(H2O)2] and crystallizes in the monoclinic system (space group P2(1), Z = 2) with a = 12.4090(8), b = 24.7688(16), c = 14.4358(11) Å, β = 91.979(7)°. Two ligand monoanions are bound in a bidentate coordination mode to Cd(II) via the carboxylate and the primary hydroxyl oxygens occupying the equatorial plane of the complex. The axial positions of the inner coordination sphere of Cd(II) are filled by two water molecules additionally engaged in intramolecular hydrogen bonds. The Hg(II) complex (2), [Hg(C36H60O11)(H2O)], crystallizes in the orthorhombic system (space group P2(1)2(1)2(1), Z = 4) with a = 12.7316(2), b = 16.4379(3), c = 18.7184(4) Å. The monensic acid reacts with Hg(II) in a tetradentate coordination manner via both oxygen atoms of the carboxylate function and oxygens of two hydroxyl groups. The twofold negative charge of the ligand is achieved by deprotonation of carboxylic and secondary hydroxyl groups located at the opposite ends of the molecule. Hg(II) is surrounded by five oxygen atoms in a distorted square pyramidal molecular geometry.
  相似文献   

18.
Preparation and properties of the following NiII and CuII complexes of the Schiff base derived from acetophenone and ethylenediamine (BAPE) and also of the mixed NiII and CuII chelates with BAPE and acetylacetone (acac-H) are described: In each case the Schiff base, BAPE, acts as a neutral bidentate ligand. The complexes are characterised by electronic spectra, magnetic susceptibilities, conductivities and elemental analyses. Pseudotetrahedral structure is proposed for M(BAPE)C12, while tetragonal structure for [M(BAPE)(acac)(H2O)2]ClO4 (M = Ni and Cu). The complex [Ni(BAPE) (acac)]ClO4 has been found to be square planar.  相似文献   

19.
Three new Schiff base complexes, namely [Mn(L)Cl] · H2O (1), [Co(L)Cl]2 · 2CH3COCH3 (2) and [Co(L)NCS]2 (3), where H2L = 2,2′-[propane-1,2-diylbis(nitriloeth-1-yl-1-ylidene)]diphenol, have been prepared and characterized. The syntheses of 1 and 2 have been achieved by reacting equimolar amounts of the respective metal chloride and the tetradentate Schiff base ligand (H2L). While the mononuclear Mn(III) complex 1 was obtained with MnCl2 in acetone medium, the same synthetic system yielded the binuclear Co(III) complex 2 in the presence of CoCl2. Dissolution of 1 and 2 followed by crystallization with ammonium thiocyanate in methanol yielded two isostructural phenoxo-bridged binuclear complexes, namely [Mn(L)NCS]2 (previously reported by us) and a new complex [Co(L)NCS]2 (3), respectively. All the complexes 13 have been characterized by microanalytical, spectroscopic, single crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1 adopts a distorted tetragonal pyramidal geometry while 2 and 3 comprise dimeric Co(III) units with bridging phenolate oxygen atoms. All the complex units in 1–3 and the respective solvent molecules are held together by weak intermolecular H-bonding to constitute a supramolecular network in the solid state. The antibacterial activity of the complexes has been tested against some Gram(+) and Gram(?) bacteria.  相似文献   

20.
A polymeric thiocyanato-bridged Schiff base copper(II) complex [Cu(L)(NCS)] n , where L is 4-nitro-2-[(2-piperidin-1-ylethylimino)methyl]phenolate, has been synthesized and structurally characterized by elemental analysis, infrared spectra, and single crystal X-ray diffraction. The complex crystallizes in the monoclinic space group P21 with a = 8.527(5), b = 10.296(6), c = 9.697(6) Å, β = 103.77(2)°, V = 826.8(8) Å3, Z = 2. In the complex, the Cu atom is in a square pyramidal coordination with one O and two N donor atoms of the Schiff base ligand and with one thiocyanate N atom, defining the basal plane, and with one symmetry related thiocyanate S atom occupying the apical position. The thiocyanate ligand links the Cu atoms through the end-to-end bridging mode.  相似文献   

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