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1.
In this study, simultaneous TG/DTG–DTA technique was used for the simple cobalt(II) complex [Co(dpamH)3]Br2 (1) (dpamH = 2,2′-dipyridylamine) and the novel mixed-ligand complexes [Co(dpamH)2(bpo)]Br (2) and [Co(dpamH)2(opo)]Br (3), (bpo = the anion of 2-hydroxybenzophenone and opo = the anion of 2-hydroxy-4-methoxybenzophenone), in order to determine their thermal degradation in static air and dynamic nitrogen atmospheres. The cationic complexes were characterized by physicochemical methods, spectroscopy (FT-IR, UV–Vis), and single-crystal X-ray analysis, revealing octahedral coordination around cobalt(II) with chromophore CoN4O2, being chelated by one anionic 2-hydroxy-benzophenone ligand and two neutral dpamH molecules. The compounds crystallize as ethanol or ethanol/water solvates, with solvent molecules involved, to a different extent, in hydrogen bonding giving quite different packing modes and thus influencing their stability. The differences in crystal structures are reflected in thermal stabilities of the compounds. Thus, in the crystals of 3 ethanol is more weakly bound than in 2 and anticipate that the former one exhibit lower thermal stability, which is in agreement with the results found by TG–DTA. The thermal decomposition of the title complexes was found to be a multi-step decomposition related to the release of the solvent and ligand molecules, leading at 1,000 °C to pure metallic cobalt in nitrogen atmosphere, while in air atmosphere to the expected cobalt oxides.  相似文献   

2.
A number of novel complexes of cobalt(III) trans-dioximates containing pyrazinecarboxamide were obtained: [CoBr(DfgH)2(Pzca)] · 0.125H2O (I), [CoCl(NioxH)2(Pzca)] (II), [CoCl(DmgH)(NioxH)(Pzca)] · 0.5C2H5OH · 0.5H2O (III), and [CoCl(DmgH)2(Pzca)] (IV), where DmgH, DfgH, and NioxH are the monoanions of dimethylglyoxime, diphenylglyoxime, and cyclohexane-1,2-dione dioxime, respectively; Pzca is pyrazinecarboxamide. Complexes I?CIII were examined by X-ray diffraction. In these complexes, the Co(III) atom has an octahedral environment with the pseudomacrocyclic fragment (DioxH)2 in the equatorial plane (DioxH is the ??-dioxime residue). The latter is stabilized by hydrogen bonds O-H?O. In all the complexes, the organic ligand is monodentate and coordinated through one N atom of the heterocycle so that it is trans to the halide anion.  相似文献   

3.
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   

4.
Three novel metal-organic complexes [Co(BDC)(TBZ)2] (I), [Cd2(BDC)2(TBZ)2(H2O)2] · 2(H2O) (II), [Mn2(BDC)(TBZ)4(SO4)] (III) (BDC = 1,4-benzenedicarboxylate, TBZ = thiabendazole) have been prepared and characterized by IR spectrum, elemental analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. X-ray structure analysis reveals that both three complexes are one-dimensional chain polymers. The 1D chain architecture of I is constructed from terephthalic acid and cobalt atoms. A simultaneous presence of chelating and monodentate coordination modes of BDC ligands is observed in complex II. In complex III, the coordinated BDC ligands adopt monodentate mode and with SO 4 2? anions alternately bridge the Mn2+ ions into 1D chains. The 3D structures of the three complexes are stabilized by π-π stacking interactions and hydrogen-bonds.  相似文献   

5.
Two new chelating radical ligands, NITphtrz (4,4,5,5-tetramethyl-2-(2-phenyl-1,2,3-triazole-4-yl)imidazoline-1-oxyl-3-oxide) and IMphtrz (4,4,5,5-tetramethyl-2-(2-phenyl-1,2,3-triazole-4-yl)imidazoline-1-oxyl), and their cobalt(II) complexes [Co(Hfac)2(NITphtrz)] (I) and [Co(Hfac)2(IMphtrz)] (II) (Hfac = hexafluoroacetylacetonate) have been prepared and characterized by IR, magnetic, and single-crystal X-ray analysis. The magnetic behaviors of the lignad NITphtrz and complex I have been discussed.  相似文献   

6.
The first MnIII complexes with Schiff bases and tricyanomethanide-anion were synthesized: [Mn(salen)C(CN)3(H2O)] (1), [Mn(5-Brsalen)C(CN)3(H2O)] (2), [Mn(salpn)C(CN)3(H2O)] (3), [Mn(3-MeOsalen)C(CN)3(H2O)] (4), [Mn(5-Brsalen)(MeOH)(H2O)][C(CN)3] (5), and [Mn(3-MeOsalpn)(H2O)2][C(CN)3] (6), where SalenH2 is N,N′-bis(salicylidene)ethylenediamine, 5-BrsalenH2 is N,N′-bis(5-bromosalicylidene)ethylenediamine, SalpnH2 is N,N′-bis-(salicylidene)-1,3-diaminopropane, 3-MeOsalenH2 is N,N′-bis(3-methoxysalicylidene)-ethylenediamine, 3-MeOsalpnH2N,N′-bis(3-methoxysalicylidene)-1,3-diaminopropane. The tricyanomethanide anion in complexes 14 acts as a the terminal ligand, whereas in complexes 5 and 6 tricyanomethanide is not coordinated by MnIII and acts as an out-of-sphere counterion. The structures of complexes 14 are characterized by the formation of dimers due to hydrogen bonds between the water molecules and oxygen atoms of the Schiff bases. The Mn...Mn distances inside the dimers are 4.69–5.41 Å. Complex 6 has a zigzag chain structure consisting of the [Mn(3-MeOsalpn)(H2O)2]+ cations bound by double bridging aqua ligands. The study of the magnetic properties of complexes 1, 3, 4, and 6 showed the existence of antiferromagnetic interactions between the MnIII ions through the system of hydrogen bonds.  相似文献   

7.
Two new cobalt(III) complexes of the hexadentate ligand [1,4-bis[o-(pyridine-2-carboxamidophenyl)]-1,4-dithiobutane] (H2bpctb) with N4S2 donor set atoms have been synthesized. A reaction of Co(CH3COO)2·4H2O with (H2bpctb) leads to the formation of [CoIII(bpctb)]PF6 (1) having a CoN2(pyridine)N′2(amide)S2(thioether) coordination by symmetric bpctb2? ligand. A similar reaction under slightly different conditions, however, gives [CoIII(L a )(L b )] (2), resulting from a C–S bond cleavage reaction triggered by an acetate ion as a base, having CoN2(pyridine)N′2(amide)S(thioether)S′(thiolate) coordination. These two Co(III) complexes have been characterized by elemental analyses and spectroscopic methods, and the crystal and molecular structures of [CoIII(bpctb)]PF6 (1) in the form of the solvate (1·MeOH·H2O) and of [CoIII(L a )(L b )] (2) have been determined by X-ray crystallography. The Co atoms of both complexes exhibit distorted octahedral geometry. The electrochemical investigation of [Co(bpctb)]PF6·MeOH·H2O (1·MeOH·H2O) and [CoIII(L a )(L b )] (2) by cyclic voltammetry reveals a reversible CoIII–CoII redox process at E 1/2 = ?0.32 V (ΔE p = 80 mV); for 1, and E 1/2 = ?0. 87 V (ΔE p = 70 mV) for 2.  相似文献   

8.
Four coordination compounds of copper(II) were synthesised and characterised in solid state by elemental analysis, infrared, electronic and EPR spectroscopy, as well as by thermal analysis (TG/DTA). The complexes were formulated on the basis of experimental data as: [Cu(BzIm)2(H2O)]·H2O (1), [Cu2(Acr)4(HBzIm)2] (2), [Cu(Acr)2(HBzIm)2] (3) and [Cu(Acr)2(HBzIm)2(H2O)]·H2O (4). IR data are in accordance with the unidentate nature of benzimidazole, in complexes (2), (3) and (4), and bridge bidentate nature of benzimidazole, in complex (1), while acrylato acts as uni- or bridge/chelate ligand. The electronic spectra display the characteristic pattern of square planar, square pyramidal, or octahedral stereochemistry, also confirmed by EPR spectra. Thermal decomposition evidenced several well-defined steps as dehydration of complexes (1) and (4), benzimidazole molecule releases for all complexes and acrylate decomposition in carbonate for complexes (3) and (4). In all four cases, the final residue after thermal treatment in air flow is copper(II) oxide, formed during the decomposition steps for complexes (3) and (4), and, respectively, after the oxidation of the metallic copper for complexes (1) and (2). Antimicrobial activities of the complexes have been determined by in vitro assays, against various Gram-negative and Gram-positive bacterial and fungal strains. Copper(II) complexes were also evaluated for their cytotoxicity on eukaryotic cells.  相似文献   

9.
We report the preparation of bromo-aryl functionalized bis(diphenylphosphino)amine ligands of the type Ph2PNArPPh2 (1, Ar = p-BrC6H4; 2, Ar = p-BrC6H4–C6H4) and their coordination properties. Mono- and dinuclear complexes were formed with Cu(I), Au(I), Pd(II), Pt(II) and tetranuclear cobalt carbonyl clusters were obtained. The crystal structures of [PdCl2(1)] (3), [PdCl2(2)] (4), [(AuCl)(μ-1)] (6), [Co4(CO)5(μ-CO)3(μ-dppa)(μ-1)] (dppa = Ph2PNHPPh2) (8) and [Co4(CO)5(μ-CO)3(μ-dppm)(μ-1)] (dppm = Ph2PCH2PPh2) (9) have been determined by X-ray diffraction. Whereas the diphosphine ligands chelate the metal center in 3 and 4, and in the Pt(II) complex 5 which is analogous to 3, ligand 1 acts as a bridge in 6 where the separation between the two Au(I) centers is 3.0402(5) Å. In the tetranuclear clusters 8 and 9, and in the cluster 10 analogous to 9 with 2 as bridging ligand, two orthogonal Co–Co edges are bridged by a diphosphine ligand and each cobalt center is thus coordinated by one P donor. Complex 3 was shown to react with the Pd(0) complex [Pd(dba)2] (dba = dibenzylideneacetone) to afford a tetranuclear complex resulting from both the insertion of Pd(0) into the ligand C–Br bond and Pd(II)/Pd(0) comproportionation to form a doubly ligand-bridged Pd(I)–Pd(I) core.  相似文献   

10.
Two cobalt(II) coordination polymers, [Co(L1)(tbi)(H2O)] n (1) and [Co(L2)(tbi)] n (2) (L1 = 1,4-bis(benzimidazole)butane, L2 = 1,4-bis(2-methylbenzimidazole)butane, H2tbi = 5-tert-butyl isophthalic acid) have been synthesized under hydrothermal conditions and characterized by physicochemical and spectroscopic methods as well as by single-crystal X-ray diffraction analysis. Both complexes exhibit similar 2D (4,4) layer structures, constructed from tbi2? and bis(benzimidazole)-based bridging ligands. The cobalt centers display different coordination environments, with an octahedral geometry in 1 and a distorted square-pyramidal configuration in 2. The thermal stabilities, fluorescence and catalytic properties of both complexes have been investigated.  相似文献   

11.
Two new polymeric networks, [Co(pbbm)(nip)] · H2O (1) and [Ni(pbbm)(nip) · (H2O)] (2) (pbbm = 1,1-(1,3-propanediyl)bis-1H-benzimidazole, H2nip = 5-nitroisophthalic acid) have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Complex 1 is an interesting one-dimensional (1D) tube-like chain utilizing [Co2(pbbm)2] metallocycle as subunit. Complex 2 is also an interesting 1D tube-like chain based on [Ni2(pbbm)2] loop subunit. In the title complexes, the ??-?? stacking and H-bonding interactions extend the 1D tube into 3D supramolecular framework, respectively. The structural differences between the title complexes indicate the importance of metal ions for the creation of molecular architectures. Furthermore, the luminescent properties of 1 and 2 were investigated.  相似文献   

12.
Four new mononuclear triazido-cobalt(III) complexes [Co(L 1/2/4 )(N3)3] and [Co(L 3 )(N3)3]·CH3CN where L 1  = [(2-pyridyl)-2-ethyl]-(2-pyridylmethyl)-N-methylamine, L 2  = [(2-pyridyl)-2-ethyl]-[6-methyl-(2-pyridylmethyl)]-N-methylamine, L 3  = [(2-pyridyl)-2-ethyl]-[3,5-dimethyl-4-methoxy-(2-pyridylmethyl)]-N-methylamine, and L 4  = [(2-pyridyl)-2-ethyl]-[3,4-dimethoxy-(2-pyridylmethyl)]-N-methylamine, respectively, were synthesized and structurally characterized. The four complexes were characterized by elemental microanalyses, IR and UV–VIS spectroscopy and X-ray single crystal crystallography. The complexes display two strong IR bands over the frequency region 2,020–2,050 cm?1 assigned for the asymmetric stretching frequency, νa(N3) of the coordinated azides indicating facial geometry. The molecular structure determinations of the complexes were in complete agreement with fac-[Co(L)(N3)3] conformation in distorted octahedral Co(III) environment.  相似文献   

13.
Four new cobalt(II)-based metal–organic coordination polymers, namely {[Co(L)(ox)]·3H2O}n (1), [Co2(L)(chda)2]n (2), {[Co(L)(mip)(H2O)]·H2O}n (3) and [Co(L)(oba)]n (4), [L = N,N′-bis(pyridine-3-yl)pyridine-3,5-dicarboxamide, H2ox = oxalic acid, H2chda = trans-1,4-cyclohexanedicarboxylic acid, H2mip = 5-methylisophthalic acid, H2oba = 4,4′-oxybis(benzoic acid)] were hydrothermally synthesized and structurally characterized by IR, TG, PXRD and single-crystal X-ray diffraction. In 1, the oxalate anions display μ 2-bridging mode connecting the adjacent 1D [Co–L]n zigzag chains to afford a 2D layer. In 2, the chda anions take the μ 4-bridging mode connecting the neighboring four CoII ions to construct a [Co–chda]2n 1D double chain, which contains the Co2(CO2)4 paddle-wheel subunit. These double chains are further linked by L ligands to furnish a 2D layer. In 34, Co(II) ions are linked by L ligands to give rise to a 1D left-, right-helical chain [Co–L]n, respectively. These helical chains are further linked by μ 2-bridging mip and oba anions to furnish a 2D network, respectively. The Co(II) ions, L ligands and dicarboxylates exhibit different coordination modes and conformations. The effect of organic dicarboxylates with different rigidity and length on the structures of the Co(II) complexes is discussed. The fluorescence, electrochemical behaviors and photocatalytic activities of the title complexes are reported.  相似文献   

14.
Two new Co(II) coordination polymers, [Co(L)(glu)] (1) and [Co(L)(npht)]·H2O (2) (H2glu = glutaric acid, H2npht = 3-nitrophthalic acid, L = 1,4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene), have been hydrothermally synthesized by self-assembly of cobalt chloride with a semi-rigid bis(benzimidazole) derivative and different organic bicarboxylic acids. Single crystal X-ray diffraction analysis reveals that complex 1 is a one-dimensional tube-like coordination polymer containing one helical [Co-L] and two linear [Co-glu] chains. In complex 2, two npht ligands connect two Co(II) atoms to form a binuclear [Co(npht)]2 subunit, which is further linked by L ligands with two kinds of conformations to form a 3-D CdSO4-like framework. In addition, the electrochemical behaviors of the title complexes in bulk-modified carbon paste electrodes, and their thermal stabilities and fluorescent properties were investigated in this paper.  相似文献   

15.
Three complexes with the formula [Co(Ip)(CuL)(H2O)2] · H2O (I), [Co(Ip)(NiL)(H2O)2] · H2O (II), [Co(CuL)2(Hbtc)(H2O)] (III), (H2Ip = m-isophthalic acid; H2L = 2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien; H3Btc = 1,3,5-benzenetricarboxylic acid) were synthesized and structurally characterized by elemental analysis, IR and UV spectroscopy. Single-crystal X-ray analyses reveal that the complexes I and II contain neutral heterometallic binuclear CoM (for I and II, M = Cu, Ni, respectively) moieties, and complex III contains discrete neutral trinuclear CoCu2 moieties. The structures of IIII consist of two-dimensional supramolecular architecture formed by strong O-H…O intermolecular hydrogen bonds. Furthermore, the magnetic properties of complex I were investigated and discussed in detail.  相似文献   

16.
New cobalt(II), nickel(II), and copper(II) complexes based on 5-methoxycarbonyl-3-me-thylpyrazole (MePzCOOMe), [Co(MePzCOOMe)2(H2O)2](NO3)2 (I), [Ni(MePzCOOMe)2(H2O)2] (NO3)2 (II), and [Cu(MePzCOO)2(H2O)] · 3H2O (III), were synthesized. The compounds were studied by X-ray diffraction analysis, IR spectroscopy, and static magnetic susceptibility. The molecular and crystal structures of complexes I and III were determined by X-ray structure analysis.  相似文献   

17.
The new complexes [Co(ecpzdtc)3] (2) [Zn(ecpzdtc)2(py)] (3) and [Cd(ecpzdtc)2(py)]·H2O (4) have been synthesized from sodium 1-ethoxycarbonyl-piperazine-4-carbodithioate [(Na+(ecpzdtc)]. The ligand and the complexes have been characterized by elemental analyses, IR, magnetic susceptibility and single crystal X-ray data. The [Zn(ecpzdtc)2(py)] and [Cd(ecpzdtc)2(py)]·H2O complexes contain pyridine as the co-ligand. [Co(ecpzdtc)3] (2) crystallizes in the monoclinic system, whereas [Zn(ecpzdtc)2(py)] (3) and [Cd(ecpzdtc)2(py)]·H2O (4) crystallize in the triclinic system. The sulfur donor sites of the bidentate ligand chelate the metal center, forming a four-membered CS2M ring. The cobalt complex has a distorted octahedral geometry, the zinc complex is almost between trigonal bipyramidal and square pyramidal, whereas the cadmium complex is square pyramidal. The crystal structures of all the complexes are stabilized by various types of inter and intramolecular hydrogen bonding.  相似文献   

18.
Tris[2-(N-ethyl)benzimidazylmethyl]amine (Etntb) and two of its complexes, [Zn(Etntb)(cinnamate)]NO3·2DMF (1) and [Ni(Etntb)(cinnamate)·(H2O)]NO3 (2) have been synthesized and characterized by physico-chemical and spectroscopic methods. Single-crystal X-ray diffraction revealed that the complexes have different structures. In complex 1, the coordination sphere around Zn(II) is distorted trigonal bipyramidal, whereas the coordination sphere around Ni(II) is distorted octahedral in complex 2. The DNA-binding properties of the free ligand and its complexes have been investigated by electronic absorption, fluorescence, and viscosity measurements. The results suggest that the ligand and both complexes bind to DNA via an intercalative mode, and their binding affinity for DNA follows the order 1 > 2> ligand.  相似文献   

19.
The complexes [CuL2Cl2]n (1), [CoL2Cl2(H2O)2]·L (2) and [MnL2Cl2(H2O)2]·L (3) (L = 3-chloro-6-(1H-1,2,4-triazol-1-yl) pyridazine) were synthesized and characterized by physicochemical and spectroscopic methods. X-ray crystallographic analysis reveals that the Cu(II) center of complex 1 is located in a slightly distorted tetragonal pyramidal environment and bridged by chlorine atoms to generate infinite 1D chains, which are further connected into 2D supramolecular structures by C–H…Cl hydrogen bonds. The Co(II) and Mn(II) atoms in complexes 2 and 3 both have a distorted octahedral coordination sphere, and the crystal lattices include hydrogen bonds and ππ stacking interactions to yield 3D supramolecular frameworks. The antioxidant activities (influence on O2 ?? and ?OH) and antibacterial activities of the ligand L and its three complexes were also investigated.  相似文献   

20.
Three novel coordination polymers, [Ni2(tib)2(btec)]·2H2O (1), [Co2(tib)2(btec)]·2H2O (2) and [Zn4(tib)2(btec)Cl4]·2H2O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.  相似文献   

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