共查询到20条相似文献,搜索用时 15 毫秒
1.
1-(4-Aminoantipyrine)-3-tosylurea (H2L) and its three lanthanide (III) complexes, M(H2L)3 3NO3 [where M = Nd(III), Sm(III) and Eu(III)], have been synthesized and characterized. In addition, the DNA-binding properties
of the three complexes have been investigated by UV–vis (ultraviolet and visible) absorption spectroscopy, fluorescence spectroscopy,
circular dichroism (CD) spectroscopy, cyclic voltammetry, and viscosity measurements. Results suggest that the three complexes
bind to DNA via a groove binding mode. Furthermore, the antioxidant activity (superoxide and hydroxyl radical) of the metal
complexes was determined by using spectrophotometer methods in vitro. These complexes were found to possess potent antioxidant
activity and be better than standard antioxidants like vitamin C and mannitol.
Absorption spectra of the complex 3 inTris-HCl buffer upon addition of calf-thymus DNA. [complex]=1×10-5 M, [DNA]=(0-1) ×10-5 M. Arrow shows the absorbance changing upon increasing DNA concentrations. Inset: plots of [DNA]/(εa – εf) versus [DNA] for the titration of DNA with the complex. 相似文献
2.
Six new ternary rare-earth (La, Eu, Sm, Nd, Y, Yb) complexes with L-isoleucine and 1,10-phenanthroline have been synthesized. Their compositions were characterized as RE(Ile)3PhenCl3 · 4H2O (RE = La, Eu, Sm, Nd, Y, Yb; Ile = L-isoleucine; phen = 1,10-phenanthroline) by elemental analysis, EDTA titration, molar conductance measurement, UV spectra, FT-IR spectra, and TG-DTA. The average diameters of growth inhibition area and the minimal inhibitory concentration (MIC) of the complexes were studied by disc diffusion method and dilution method in nutrient broth. The results showed that the ternary rare-earth complexes strongly exhibited the antibacterial activity against Escherichia coli and Staphylococcus aureus and that their antibacterial effects were better than those of rare-earth chlorides, L-isoleucine, and 1,10-phenanthroline. 相似文献
3.
Nagababu P Shilpa M Latha JN Bhatnagar I Srinivas PN Kumar YP Reddy KL Satyanarayana S 《Journal of fluorescence》2011,21(2):563-572
The new ligand 4-(isopropylbenzaldehyde)imidazo[4,5-f ][1,10]phenanthroline (ippip) and its complexes [Ru(phen)2(ippip)]2+(1),[Co(phen)2(ippip)]3+(2),[Ru(bpy)2(ippip)]2+(3),[Co(bpy)2(ippip)]3+(4)(bpy=2,2-bipyridine) and (phen=1,10-phenanthroline) were synthesized and characterized by ES+-MS, 1H and 13C NMR. The DNA binding properties of the four complexes were investigated by different spectrophotometric methods and viscosity
measurements. The results suggest that complexes bind to calf thymus DNA (CT-DNA) through intercalation. When irradiated at
365 nm, the complexes promote the photocleavage of pBR322 DNA, and complex 1 cleaves DNA more effectively than 2, 3, 4 complexes
under comparable experimental conditions. Furthermore, photocleavage studies reveal that singlet oxygen (1O2) plays a significant role in the photocleavage. 相似文献
4.
Hexadentate ligand L and its Ln3+ complexes EuLCl3 (1), TbLCl3 (2), SmLCl3 (3) are synthesised. All these complexes are well characterized for their photophysical properties such as luminescence lifetime decay(τ) and overall quantum yield(Φ). These complexes being water soluble, depicts their intense metal centred luminescence. Effect of pH on these complexes suggest that their emission intensities are stable in the pH range 4–9 and show their compatibility to function in the physiological pH. 相似文献
5.
Two new La(III) and Sm(III) complexes with enrofloxacin (HER, 1-cyclopropyl-7-(4-ethyl-1-piperazinyl)-6-fluoro-1,4-dihydro-4-oxo-3-quinoline carboxylic acid, C(19)H(21)FN(3)O(3)), [La(2)(ER)(6)(H(2)O)(2)]·14H(2)O(1) and [Sm(2)(ER)(6)(H(2)O)(2)]·14H(2)O(2) have been synthesized and characterized by elemental analysis, FT-IR, TG-DTG and X-ray single crystal diffraction. Both of the complexes are triclinic system with space group Pī. The structure of the complexes show that each rare earth atom in both complexes was nine-coordinated. Two of the enrofloxacin ions acted as tridentate chelate and bridging ligands, while the others as bidentate chelate ligands. The binding reaction between the complexes and bovine serum albumin (BSA) was studied by UV-vis absorption spectra and fluorescence spectroscopy. The results indicated that the two complexes had a quite strong ability to quench the fluorescence from BSA and the binding reaction was mainly a static quenching process. The binding constants K ( A )/(L·mol(-1)) were 1.46 × 10(5)(1) and 8.59 × 10(6)(2) and one binding site was formed. The synchronous spectroscopy suggested that tryptophan residues were placed in BSA. It was also found that the two complexes exhibited greater antimicrobial activity than enrofloxacin at given concentrations. 相似文献
6.
7.
Some nickel(II) and zinc(II) complexes of the type [Ni(L)(phen/bipy)]X (1a–6a) and [Zn(L) (phen/bipy)]X (1b–6b) (where L = 2-{(E)-[(4-trimethylsilylethynylphenyl)imino]methyl}-4-(4-nitro phenylethynyl)phenol; phen = 1, 10-phenanthroline, bipy = 2, 2´-bipyridine; X = ClO4 ?, BF4 ?, PF6 ?) have been prepared and characterized on the basis of elemental analyses, FTIR, 1H NMR and mass spectral studies. The molecular structure of L was determined by single crystal X-ray diffraction studies. The electrochemical behaviour of the Ni(II) complexes indicate that the phen complexes appears at more positive potential as compared to those for bipy complexes, as a consequence of its strong π-acidic character. TGA was carried out to study the thermal behavior of the complexes. Room temperature luminescence is observed for all complexes corresponds to π → π* ILCT transition. The size of the counter anion and heterocyclic coligands phen and bipy shows marked effect on emission properties of the complexes. 相似文献
8.
Yata PK Shilpa M Nagababu P Reddy MR Kotha LR Gabra NM Satyanarayana S 《Journal of fluorescence》2012,22(3):835-847
The three Ru(II) complexes of [Ru(phen)2dppca]2+ (1) [Ru(bpy)2dppca]2+ (2) and [Ru(dmb)2dppca]2+ (3) (where phen = 1,10 phenanthroline, bpy = 2,2-bipyridine, dmb = 2 ,2-dimethyl 2′,2′-bipyridine and polypyridyl ligand
containing a single carboxylate functionality dppca ligand (dipyridophenazine-11-carboxylic acid) have been synthesized and
characterized. These complexes have been shown to act as promising calf thymus DNA intercalators and a new class of DNA light
switches, as evidenced by UV-visible and luminescence titrations with Co2+ and EDTA, steady-state emission quenching by [Fe(CN)6]4− and KI, DNA competitive binding with ethidium bromide, viscosity measurements, and DNA melting experiments. The results suggest
that 1, 2, and 3 complexes bind to CT-DNA through intercalation and follows the order 1 > 2 > 3. Under irradiation at 365 nm,
the three complexes have also been found to promote the photocleavage of plasmid pBR322 DNA. 相似文献
9.
Shilpa M Nagababu P Kumar YP Latha JN Reddy MR Karthikeyan KS Gabra NM Satyanarayana S 《Journal of fluorescence》2011,21(3):1155-1164
Three symmetric ligands 7-methyl dipyrido-[3,2-a;2′,3′-c]phenazine (dppz-CH3), 7-nitro dipyrido-[3,2-a;2′,3′-c]phenazine (dppz-NO2) and benzo[i]dipyrido-[3,2-a;2′,3′-c]phenazine (dppn) and their ruthenium(II) complexes [Ru(en)2(L)][ClO4]2 (en= ethylenediamine), L= dppz-CH3, dppz-NO2 and dppn have been synthesized and characterized by IR, 1H, 13C NMR and Mass spectra. The interactions of these complexes with calf thymus DNA have been investigated by spectrophotometric,
spectrofluorimetric, circular dichroism, viscosity and thermal denaturation studies. As the planar extension of the intercalative
ligand increases, the interaction of the complex with DNA increases, indicating that the size and shape of the intercalalative
ligand has a marked effect on the strength of interaction. The plot of log K versus log [Na+] yield a slope of -1.26, -1.53, -1.60 for the complexes 1, 2 and 3 respectively. These three complexes have been found to
promote the cleavage of plasmid pBR 322 DNA upon irradiation. 相似文献
10.
A novel Schiff base ligand, chromone-3-carbaldehyde-aminophenazone (L) and its Ln(III) (Ln = La, Yb) complexes were synthesized
and characterized by physicochemical methods. The interaction between the ligand, Ln(III) complexes and calf thymus DNA in
physiological buffer (pH = 7.10) was investigated by using UV–vis spectroscopy, fluorescence spectra, ethidium bromide experiments
and viscosity measurements, indicating that the studied compounds can all bind to DNA via an intercalation binding mode and
the complexes have stronger binding affinity than the free ligand alone. Furthermore, antioxidant activity of the ligand and
its complexes was determined by superoxide and hydroxyl radical scavenging methods in vitro, suggesting that Ln(III) complexes
inhibit stronger antioxidant activity than the ligand alone and some standard antioxidants, such as mannitol and vitamin C. 相似文献
11.
以18β-甘草次酸和4-氨基苯酚为原料,在N,N'-二环己基碳二酰亚胺(DCC),1-羟基苯并三唑(HOBt)/4-N,N-甲基吡啶(DMAP),N-甲基吗啉(NMM)作用下合成了N-(4-羟基-苯基)-甘草次酸酰胺,通过DCC、DCC/HOBt催化有机酸形成酯、酰胺反应的历程解释了在DCC/HOBt催化体系中目标化合... 相似文献
12.
在非水体系中首次合成了Y(Ⅲ)、Nd(Ⅲ)与双希夫碱2-羟基-2-甲氧基苯甲醛缩联苯胺的固体配合物。用元素分析,摩尔电导,红外光谱,紫外光谱,核磁共振谱等方法研究共组成、一般性质和结构。 相似文献
13.
Ju Wang Zheng-Yin Yang Bao-Dui Wang Xu-Yang Yi Yong-Chun Liu 《Journal of fluorescence》2009,19(5):847-856
A novel 6-ethoxy chromone-3-carbaldehyde benzoyl hydrazone (L) and its Ln(III) complexes, [Ln = Sm (1), Eu (2), Gd (3), Tb (4)], have been synthesized and characterized. The fluorescence properties of the Eu(III) and Sm(III) complexes in solid state
and Eu(III) complex in different solutions (DMF, DMSO, methanol and acetonitrile) were investigated. At the same time, the
DNA-binding properties of the two complexes are investigated using UV-Vis absorption spectroscopy, fluorescence spectroscopy,
viscosity measurement. All the experimental evidences indicate that the two complexes can bind to CT-DNA via an intercalation
mechanism. Furthermore, antioxidant activity tests in vitro showed that the complexes have significant antioxidative activity
against hydroxyl free radicals from the Fenton reaction. 相似文献
14.
以硝酸铕、2-(4-氟代苯甲酰基)苯甲酸(HL)、1,10-菲咯啉(Phen)和三苯基氧膦(TPPO)合成了EuL3(H2O)6,EuL3Phen(H2O)4和EuL3(TPPO)(H2O)5三种固态配合物。用元素分析、红外光谱、核磁共振氢谱对配合物进行了组分确定和结构表征。IR表明,2-(4-氟代苯甲酰基)苯甲酸与Eu3+形成配合物后,位于1 692 cm-1处羧基的νCO峰消失,2 500~3 200 cm-1处羧基的νO—H峰也消失,出现了羧酸盐特有的反对称伸缩振动吸收峰(νas(CO-2))和对称伸缩振动吸收峰(νs(CO-2)),且Δν(νas(CO-2)-νs(CO-2))与钠盐的Δν相近,说明羧酸根与Eu3+以对称双齿桥式配位。在1H NMR中,形成配合物后第一配体苯环上的质子峰变为宽峰且移向高场,Phen和TPPO中质子化学位移移向低场。室温下测定了配合物的荧光激发光谱和发射光谱,激发光谱表明配合物EuL3(H2O)6,EuL3Phen(H2O)4和EuL3(TPPO)(H2O)5的最佳激发波长分别为353.0,355.0和357.0 nm;发射光谱均显示Eu3+离子的特征发射光谱,且表明Phen对Eu3+离子的荧光发射有明显增强作用。 相似文献
15.
以硝酸铕、2-(4-氟代苯甲酰基)苯甲酸(HL),1,10-菲咯啉(Phen)和三苯基氧膦(TPP0)合成了EuL3(H2O)6,EuL3 Phen(H2O)4和EuL3(TPPO)(H2O)5三种固态配合物.用元素分析、红外光谱、核磁共振氢谱对配合物进行了组分确定和结构表征.IR表明,2-(4-氟代苯甲酰基)苯甲酸与Eu3+形成配合物后,位于1 692 cm-1处羧基的νc=0,峰消失,2 500~3 200cm-1处羧基的νo-H峰也消失,出现了羧酸盐特有的反对称伸缩振动吸收峰(va(CO2-))和对称伸缩振动吸收峰(νs(CO2-)),且△ν(νas(CO2-)-νs(C(O2-))与钠盐的△ν相近,说明羧酸根与Eu3+以对称双齿桥式配位.在HNMR中,形成配合物后第一配体苯环上的质子峰变为宽峰且移向高场,Phen和TPPO中质子化学位移移向低场.室温下测定了配合物的荧光激发光谱和发射光谱,激发光谱表明配合物EuL3(H2O)6,EuL3 Phen (H2O)4和EuL3(TPPO)(H2O)5的最佳激发波长分别为353.0,355.0和357.0 nm;发射光谱均显示Eu3+离子的特征发射光谱,且表明Phen对Eu3+离子的荧光发射有明显增强作用. 相似文献
16.
17.
Zayed Mohie E. M. Alzahrani Khalid Ahmed Khan Salman A. 《Journal of fluorescence》2021,31(6):1823-1831
Journal of Fluorescence - Novel alkylated heterocyclic chalcone (E)-1-(2-(allyloxy)phenyl)-3-(9-ethyl-9H-carbazol-3-yl)prop-2-en-1-one (AECO) with extended π-bond was prepared by the... 相似文献
18.
Wen-Xian Li Wen-Juan Chai Xiao-Jun Sun Tie Ren Xiao-Yan Shi 《Journal of fluorescence》2010,20(4):873-880
Two novel ternary rare earth complexes of Tb(III) and Dy(III) perchlorates with bis(benzoylmethyl) sulfoxide (L) and benzoic
acid (L′) had been synthesized and characterized by elemental analysis, coordination titration analysis, molar conductivity,
IR, TG-DSC, 1HNMR and UV spectra. The results indicated that the composition of these complexes was REL5L′(ClO4)2·nH2O (RE= Tb(III), Dy(III); L=C6H5COCH2SOCH2COC6H5, L′=C6H5COO; n = 6,8). The fluorescence spectra illustrated that the ternary rare earth complexes presented stronger fluorescence intensities,
longer lifetimes and higher fluorescence quantum efficiencies than the binary rare earth complexes REL5·(ClO4)3·2H2O. After the introduction of the second ligand benzoic acid group, the relative fluorescence emission intensities and fluorescence
lifetimes of the ternary complexes REL5L′(ClO4)2·nH2O (RE= Tb(III), Dy(III)) enhanced more obviously than the binary complexes. This indicated that the presence of both organic
ligands bis(benzoylmethyl) sulfoxide and the second ligand benzoic acid could sensitize fluorescence intensities of rare earth
ions, and the introduction of benzoic acid group was resulted in the enhancement of the fluorescence properties of the ternary
rare earth complexes. The phosphorescence spectra were also discussed. 相似文献
19.
A new ligand, 3-carbaldehyde chromone-(benzoyl) hydrazone (L), was prepared by condensation of 3-carbaldehyde chromone with
benzoyl hydrazine. Its four rare earth complexes have been prepared and characterized on the basis of elemental analyses,
molar conductivities, mass spectra, 1H NMR spectra, UV-vis spectra, fluorescence studies and IR spectra. The Sm(III) complex exhibits red fluorescence under UV
light and the fluorescent properties of Sm(III) complex in solid state and different solutions were investigated. In addition,
the DNA binding properties of the ligand and its complexes have been investigated by electronic absorption spectroscopy, fluorescence
spectra, ethidium bromide displacement experiments, iodide quenching experiments, salt effect and viscosity measurements.
Experimental results suggest that all the compounds can bind to DNA via an intercalation binding mode. Furthermore, the antioxidant
activities of the ligand and its complexes were determined by superoxide and hydroxyl radical scavenging methods in vitro.
The rare earth complexes were found to possess potent antioxidant activities that are better than those of the ligand alone. 相似文献
20.
Optics and Spectroscopy - The spectral-luminescent properties of europium(III) complexes with p-methylbenzoic acid and nitrogen- and phosphorus-containing neutral ligands of compositions... 相似文献