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1.
Two new nickel complexes, [Ni(L1)2]?·?2(CH3OH) (1) and [Ni(L2)2]?·?2(CH3OH) (2), where HL1 is 4-chloro-2-((2-hydroxy-ethylimino)methyl)phenol and HL2 is 4-fluoro-2-((2-hydroxy-ethylimino)methyl)phenol, have been synthesized and characterized by single-crystal X-ray diffraction and UV-Vis absorption spectra. The coordination polyhedron of nickel(II) in each complex can be described as distorted octahedral. The interactions between the complexes and calf thymus (CT)-DNA/DNA were investigated by UV-Vis spectra and agarose gel electrophoresis. The results show that the complex transforms supercoiled to nicked form and exhibits effective DNA cleavage activity via hydrolytic cleavage mechanism.  相似文献   

2.
Three new mononuclear cobalt(II) complexes containing ligands with extended planar quinoxaline moieties, {dipyrido[3,2‐a:2′,3′‐c]phenazine (dppz) or dipyrido[3,2‐d:2′,3′‐f]quinoxaline (dpq)}, viz. [Co(dppz)(acac)2] · CH3OH ( 1 ), [Co(dpq)(tfnb)2] ( 2 ) and [Co(dpq)(dbm)2] ( 3 ), where acac = acetylacetonate, tfnb = benzoyltrifluoroacetone and dbm = dibenzoylmethane, have been synthesized and structurally characterized as octahedral complexes. The binding ability of the complexes with calf thymus (CT)‐DNA has been investigated by spectroscopic and viscosity measurements. Results indicate that all complexes bind to CT‐DNA via intercalative mode, and the DNA binding affinity of dppz complex 1 is apparently stronger than that of dpq complexes 2 and 3 . Furthermore, DNA photocleavage experiments indicate that these complexes are efficient DNA cleaving agents in UV‐A (365 nm) and hydroxyl radical (HO·), singlet oxygen (1O2) and superoxide anion (1O2?) serve as the major cleavage active species. In addition, interaction of the complexes with bovine serum albumin (BSA) was investigated using UV ? visible and fluorescence methods, which indicated that all complexes could quench the intrinsic fluorescence of BSA in a static quenching process. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

3.
Three binuclear phenolate complexes, [Ni2(L1)2(OAc)](BPh4)·DMF (1), [Ni2(L2)2(OAc)](BPh4) (2), and [Ni2(L3)2(OAc)](OH)·3H2O (3), where L1 = 2-{[bis-(2-hydroxy-ethyl)-amino]-methyl}-4-methyl-phenol, L2 = 2-{[bis-(2-hydroxy-ethyl)-amino]-methyl}-4-methoxy-phenol, and L3 = 2-{[bis-(2-hydroxy-ethyl)-amino]-methyl}-4-tert-butyl-phenol), have been synthesized. Single-crystal diffraction reveals that all the metal atoms are in a distorted octahedral geometry. The interactions of the complexes with calf thymus DNA (CT-DNA) have been investigated by UV–vis absorption, fluorescence emission, and circular dichroism spectroscopy and viscosity measurements. Furthermore, DNA cleavage mechanism shows that the complexes may be capable to promote DNA cleavage through oxidative DNA damage pathway, which is indicative of the involvement of hydroxyl radical, singlet oxygen, or singlet oxygen-like entity in the cleavage process. Cytotoxicity studies on the Hela and MCF-7 cancer cell lines show that complexes 1–3 exhibit excellent activity toward the tested tumor cell lines with respect to the standard drug carboplatin, revealing that they have the potential to act as effective metal-based anticancer drugs.  相似文献   

4.
Five new mononuclear zinc(II) complexes containing ligands with extended planar phenanthroline moieties (dipyrido‐[3,2‐a:2′,3′‐c]phenazine (dppz) or dipyrido[3,2‐d:2′,3′‐f] quinoxaline (dpq)), namely [Zn(dppz)(acac)2]⋅CH3OH ( 1 ), [Zn(dppz)(dbm)(OAc)] ( 2 ), [Zn(dpq)(dbm) (OAc)] 1.5H2O ( 3 ), [Zn(dpq)(tfnb)(OAc)] ( 4 ) and [Zn(dpq)(tfnb)2] ( 5 ), where acac = acetylacetonate, tfnb = benzoyltrifluoroacetone and dbm = dibenzoylmethane, were synthesized and structurally characterized. The binding ability of complexes 1 – 5 with calf thymus DNA was investigated by spectroscopic titration methods and viscosity measurements. Results indicate that all complexes bind to calf thymus DNA via intercalative mode, and the DNA binding affinities of dppz complexes 1 and 2 are apparently stronger than those of dpq complexes 3 – 5 . DNA photocleavage experiments reveal that these complexes are efficient DNA cleaving agents and they are more active in UV‐A (365 nm) than in visible light. In particular, the in vitro cytotoxicity of the complexes for human cancer cell line A549 demonstrates that the five compounds have anticancer activity with low IC50 values. Meanwhile, interaction of the complexes with bovine serum albumin investigated using UV–visible and fluorescence methods indicates that all complexes can quench the intrinsic fluorescence of bovine serum albumin in a static quenching process.  相似文献   

5.
Two 2-terephthalate (tp) bridged complexes, [Cu2(tp)(pren)4](ClO4)2 (pren = 1,3-diaminopropane) (1) and [Ni2(tp)(pren)4(Him)2](ClO4)2 (Him = imidazole) (2), have been synthesized and characterized by X-ray single-crystal structural analysis. In the discrete dinuclear [Cu2(tp)(pren)4]2+ cation of complex (1), each CuII atom has a square-pyramidal geometry, being coordinated by four nitrogen atoms (avg. 2.031 Å) from two pren ligands at the basal plane and one oxygen atom [2.259(3) Å] from a bis-monodentate tp group at the axial position. In the discrete dinuclear [Ni2(tp)(pren)4(Him)2]2+ cation of complex (2), each NiII center is coordinated by five nitrogen atoms [Ni—N 2.069(3)–2.109(2) Å] from one Him group and two pren groups, and completed by one oxygen atom [Ni—O 2.138(3) Å] from a bis-monodentate tp group to furnish a distorted octahedron. Magnetic susceptibility studies show that the pair of metal atoms, although being separated by >11.5 Å, exhibit weak intramolecular antiferromagnetic interactions in complexes (1) (g = 2.07 and J = –3.4 cm–1) and (2) (g = 2.10 and J = –0.7 cm–1). The electrochemical behaviors of the complexes have also been studied by cyclic voltammogram processes.  相似文献   

6.
Two mononuclear copper(II) complexes, [Cu(bpy)2(CH3OH)](pic)2 (1) and [Cu(Me2bpy)2(H2O)](pic)2 (2) (bpy = 2,2′-bipyridine; Me2bpy = 4,4′-dimethyl-2,2′-bipyridine; Hpic = 2,4,6-trinitrophenol), were synthesized and characterized by elemental analyses, conductivity measurements, IR, UV–Visible spectroscopy and single crystal X-ray analyses. Both complexes 1 and 2 are mononuclear compounds. The copper atom in complex 1 is in a distorted square pyramidal geometry with a CuN4O chromophore as revealed from the τ value (0.25), while the Cu(II) ion in complex 2 displays a distorted trigonal bipyramidal stereochemistry with τ = 0.72. Hydrogen bonding interactions and π–π stacking interactions link the mononuclear copper complex 1 or 2 into a 1D infinite chain. The interactions of the two mononuclear complexes with herring sperm DNA (HS-DNA) have been studied by UV–visible absorption titration, fluorescence titration and ethidium bromide (EB) displacement experiments. The results suggest that both complexes might bind to DNA by intercalation.  相似文献   

7.
Summary The nickel(II) and copper(II) complexes ofN,N-bis(dehydroaceto) ethylenediimine are monomeric and hydrated. In both compounds, coordination occurs at the C(4) carbonyl of the dehydroacetic acid moiety. The Ni atom has square-planar geometry with a water molecule at a substantial distance away. Both structurally distinct Cu atoms have square-pyramidal geometry, the apical position of one being occupied by an oxygen atom of the C(2) carbonyl group in a neighbouring molecule, and that of the other by a water molecule which participates in hydrogen-bond formation.  相似文献   

8.
The Schiff base ligand (HL) obtained from phenylmethanamine and 5-methoxysalicylaldehyde are used as ligands for Co(II) and Ni(II) resulting in complexes [Co(L)2] (I) and [Ni(L)2] (II), and their solid state structures were determined by X-ray crystallography. In both complexes, weak interactions play an important role in the molecular self-assembly. Complex I was stacked up to the 2D layers by C-H…O hydrogen bonds and C-H…π interactions. In contrast, complex II was extended into 2D sheet by C-H…O hydrogen bonds, the C-H…π interactions, and edge-to-face interactions.  相似文献   

9.
The phenolic azide bridged dinuclear nickel(II) complex, [Ni2(L1)2(N3)(H2O)(μ1,1-N3)] · EtOH (I), and the thiocyanate bridged dinuclear copper(II) complex, [Cu2(L2)21,1-NCS)2] (II), where L1 and L2 are the deprotonated forms of 2-mothoxy-6-[(2-piperidin-1-ylethylimino)methyl]phenol and 2,4-dichloro-6-[(2-methylaminoethylimino)methyl]phenol, respectively, were synthesized and characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. The crystal of I is orthorhombic: space group Pbca, a = 12.172(1), b = 20.953(1), c = 29.779(2) Å, V = 7594.8(9) Å3, Z = 8. The crystal of II is monoclinic: space group P21/n, a = 8.7615(11), b = 19.672(2), c = 16.568(2) Å, β = 99.449(2)°, V = 2816.9(6) Å3, Z = 4. The Ni atoms in I are in octahedral coordinations, and the Cu atoms in II are in square-pyramidal coordinations.  相似文献   

10.
A new azido-coordinated nickel(II) complex [NiL1(N3)] (1) and a new thiocyanato-coordinated nickel(II) complex [NiL2(NCS)] (2), where L1 and L2 are the monoanionic forms of Schiff bases 2-[(2-isopropylaminoethylimino)methyl]-6-methylphenol and 2-[(2-dimethlaminoethylimino)methyl]-6-methylphenol respectively, are prepared and structurally characterized by elemental analysis, IR spectra, and single crystal X-ray crystallography. Complex 1 crystallizes in the triclinic space group P-1 with unit cell dimensions a = 8.812(2) Å, b = 9.433(3) Å, c = 9.488(2) Å, α = 81.933(2)°, β = 69.925(2)°, γ = 84.591(2)°, V = 732.5(3) Å3, Z = 2, R 1 = 0.0291, and wR 2 = 0.0734. Complex 2 crystallizes in the monoclinic space group P21/n with unit cell dimensions a = 7.4497(4) Å, b = 6.1933(3) Å, c = 31.5126(18) Å, β = 92.484(2)°, V = 1452.57(13) Å3, Z = 4, R 1 = 0.0307, and wR 2 = 0.0668. The Ni atom in each of the complexes is coordinated by three donor atoms of the Schiff base ligand and by one N atom of the azide or thiocyanate ligand, forming a square planar geometry. The azide and thiocyanate anions readily coordinate to the complexes as secondary ligands.  相似文献   

11.
Two new zinc(II) complexes have been synthesized and studied by single crystal X-ray diffraction method: [Zn(L1)Cl2]·2DMF (1) and [Zn(L2)Cl2]·DMF (2) (L1 = 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine, L2 = 3,3′-bis[2-bis(2-ethylbenzimidazolyl)]-2,2′-dipyridine). Compound 1 is monoclinic, C2/c, a = 23.142(3) ?, b = 11.845(1) ?, c = 14.735(3) ?; compound 2 is orthorhombic, C2221, a = 12.140(7) ?, b = 16.283(9) ?, c = 16.51(1) ?. In both compounds, Zn(II) cations are coordinated by two chlorine atoms and two benzimidazole nitrogen atoms in a slightly distorted tetrahedron fashion. Structural features responsible for fluorescent properties of the complexes are discussed.  相似文献   

12.
The tridentate ligand 2-Oximino-3-thiosemicarbazone-2,3-butanedione (Hotsb) reacts with MCl2 (M = Ni2+ or Cu2+) to give rise to the mononuclear complexes [Ni(Hotsb)2]Cl2 · H2O (1) and [Cu(Hotsb)Cl2] · H2O (2). These complexes have been characterized by X-ray crystallography, spectroscopy, and cyclic voltammetry. The nickel(II) ion in (1) is in a six-coordinate octahedral environment being bonded to the two protonated tridentate ligands which occupy mer positions. The copper(II) ion in (2) is in a five-coordinate square-pyramidal geometry, in which the basal plane is made up the two nitrogens, sulfur, and chloride atom, while the other chloride atom is coordinated at the axial position. The cyclic voltammogram of the complexes displays two one-electron waves corresponding to MII/MIII and MII/MI processes. The electronic as well as infrared spectral properties of the title complexes are reported and discussed.  相似文献   

13.
[Cu(DAPT)2Cl]Cl·H2O and [Cu(DBM)(DAPT)Cl] [DAPT = 2,4-diamine-6-(pyrazin-2-yl)-1,3,5-triazine] were synthesized and characterized by IR and UV spectroscopy, elemental analysis, TG–DTA, molar conductivity, and LC–MS. The interaction with calf thymus DNA (ct-DNA) of the two complexes has been studied using UV spectra, fluorescent spectra, cyclic voltammetry, and viscosity measurements. The complexes interact with ct-DNA through classical intercalation. Fluorescence intensity changes of 1 and 2 in the absence and presence of ct-DNA have been investigated for quantitative determination of ct-DNA with the limit of detection of 3.8 and 7.7 ng mL?1, respectively. From the result, the two complexes are potentially sensitive DNA fluorescent probes.  相似文献   

14.
Mononuclear copper(II) and nickel(II) complexes with 1,3-bis(3,5-di-tert-butylsalicylideneamino)propan-2-ol (H3L) of the general formula [M(HL)] were obtained and structurally characterized. It was demonstrated that the presence of the tert-butyl groups precludes intermolecular hydrogen bonding in the crystals of the complexes and that their molecules are only linked by hydrophobic interactions.  相似文献   

15.
16.
Three Ni(II) and Zn(II) complexes [Ni(L1)], [Ni(L2)], and [Zn(L3)(DMSO)] (L1 = 2,3-bis(2-hydroxybenzylideneimino)-2,3-butenedinitrile, L2 = 2,3-bis(2-hydroxy-3-methoxybenzylideneimino)-2,3-butenedinitrile, L3 = 2,3-bis(2-hydroxy-1-naphthylideneimino)-2,3-butenedinitrile) were obtained in DMSO by one-pot syntheses. The complexes were characterized by physicochemical and spectroscopic methods. Also, their solid-state structures were determined by single-crystal X-ray diffraction. The geometries of the Ni(II) and Zn(II) complexes were square planar and square pyramidal, respectively. The complexes were screened in vitro against a fungal species and eight species of bacteria, revealing their antimicrobial activity.  相似文献   

17.
From a mononuclear Cu(II)-hydrazone complex [Cu(PBH)2] (1), one μ1,1-azido bridged dinuclear Cu(II) complex having the formula [{Cu(PBH)(μ1,1-NNN)}2] (2) (where HPBH = 2-pyridinecarboxaldehyde benzoyl hydrazone) has been synthesised. Both the complexes are characterised by elemental analyses, IR and UV–Vis spectroscopic studies. The tridentate hydrazone pro-ligand (HPBH) is obtained by the condensation of benzhydrazide and pyridine-2-carboxaldehyde. The structures of the complexes have conclusively been established by the X-ray single crystal diffraction method. Complex 1 and 2 both display DNA binding ability, which is ascertained by UV–Vis titration and cyclic voltammetric studies using calf thymus DNA (CT-DNA). The apparent binding constants (Kapp) are of moderate values and are 2.048 × 104 M−1 (±0.006) and 1.644 × 104 M−1 (±0.005), respectively. The modes of binding of the complexes with CT-DNA has been investigated using circular dichroism, ethidium bromide displacement assay and viscosity measurements. The cleavage properties of these complexes as well as the free pro-ligand with super coiled (SC) pUC19 are studied using the gel electrophoresis method, where both the complexes displayed chemical nuclease activity in the presence of H2O2 via an oxidative mechanism. The antimicrobial study using the free pro-ligand, 1 and 2 against both Gram positive and Gram negative bacteria are performed, 2 showed antimicrobial activity against both Gram negative and Gram positive bacteria whereas the free ligand and 1 show no antibacterial activity.  相似文献   

18.
Two new complexes, [Ni(HL1)(N3)(μ1,1N3)]2 (1) [HL1: NC5H4CH3C=NNH (C=O) NH2] and [Ni(L2)N3] (2) [HL2: NC5H4HC=N NH(C=S)NH2], have been synthesized by reaction of Ni(OAC)2·4H2O and sodium azide with HL1 and HL2 and characterized by elemental analysis, FT-IR, and UV–vis spectral studies. Single-crystal X-ray diffraction reveals that 1 is dinuclear with nickel(II) in an octahedral environment of NNO donors of HL1, two nitrogens of azide bridges and one nitrogen of terminal azide; 2 is mononuclear containing nickel(II) in a distorted square-planar environment of NNS donors of HL2 and one terminal azide. The structures of 1 and 2 have been optimized by density functional theory. The results of antimicrobial activities of ligands, 1 and 2 demonstrated that HL2 and 2 have good antimicrobial activity in contrast with HL1 and 1, related to the presence of sulfur donor in HL2.  相似文献   

19.
Nickel(II) and palladium(II) form neutral 1?:?2 chelates with aromatic thiohydrazides, for example. thiobenzhydrazide, o-hydroxythiobenzhydrazide, furan-2-thiohydrazide, and thiophen-2-thiohydrazide. All the compounds are diamagnetic and have been characterized by elemental analysis and spectroscopic methods. o-Hydroxythiobenzhydrazido complexes of nickel(II) and palladium(II) were crystallized from DMSO and their structures were solved by X-ray diffraction. The complexes are isostructural with planar structures. Metal ion is linked to two identical deprotonated ligands through trans hydrazinic nitrogen and sulfur. Hydrogen of OH is involved in intramolecular hydrogen-bonding.  相似文献   

20.
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