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稀土N,N′-双(2-吡啶甲酰胺)-1,2-乙烷配合物合成及与DNA的作用 总被引:1,自引:0,他引:1
合成了四种N,N′-双(2-吡啶甲酰胺)-1,2-乙烷(H2L)稀土配合物.经过对元素分析,红外光谱,紫外光谱,热重分析和摩尔电导值的分析,确定配合物的组成为:[Ln(H2L)(NO3)2](NO3)·3H2O(Ln=Sm,Eu,Gd,Tb).光谱测试结果表明:配体H2L中酰胺羰基氧和吡啶氮分别与稀土离子配位,硝酸根为双齿配体,Im(Ⅲ)与H2L形成了1∶1的螯合物.另外,通过紫外光谱、荧光光谱和表面增强拉曼光谱方法对Sm配合物与DNA之间的作用进行了初步的研究.实验结果显示随着DNA的加入[Sm(H2L)(NO3)2](NO3)·3H2O配合物在265 nm处的紫外吸收峰逐渐减小,并产生红移现象,得到配合物与DNA的结合常数为1.24×105.Sm配合物使EB-DNA体系发生荧光猝灭,由于配合物和EB争夺与DNA的结合位点,从而使体系中游离的EB增多.表面增强拉曼光谱峰的变化亦显示随着.DNA的加入配合物的谱峰强度减弱,同时1 282cm-1处的谱峰消失,说明配体的吡啶环在一定程度上插入了DNA的双螺旋平面,导致吡啶环的电子云密度发生改变.以上结果表明配合物和DNA发生了显著的作用. 相似文献
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Samy A. El-Daly Khalid A. Alamry Abdullah M. Asiri Mahmoud A. Hussein 《Journal of luminescence》2012,132(10):2747-2752
The photophysical properties such as electronic absorption, molar absorptivity, emission spectra, fluorescence quantum yield and fluorescence lifetime of N,N′-bis(4-pyridyl)-3,4:9,10-perylene bis(dicarboximide) (BPPD) have been measured in different solvents. Both electronic absorption and fluorescence spectra are not sensitive to medium polarity, while the fluorescence quantum yield (?f) is solvent dependent. The ground state geometry has been computed by using density functional theory (DFT), the transition from HOMO to LUMO from perylene core with maximum absorption at 512 nm and HOMO–LUMO energy difference equal 2.53 eV. BPPD dye undergoes molecular aggregation to dimmer or higher aggregates in dimethyl sulfoxide (DMSO). Crystalline solids of BPPD gives excimer-like emission at 676 nm. The fluorescence quenching of BPPD is also studied using hydrated ferric oxide nanoparticle (FeOOH), and the Stern–Volmer rate constants (Ksv) were calculated as 8×106 and 9.2×106 M?1 in ethanol and ethylene glycol, respectively. 相似文献
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János Mink László Hajba Imre Pápai Judith Mihály Csaba Neméth Mikhail Yu. Skripkin 《应用光谱学评论》2013,48(4):274-326
Abstract Mid-infrared, far-infrared, and Raman vibrational spectroscopic studies were combined with density functional theory (DFT) calculations and normal coordinate force field analyses for N,N′-dimethylurea (DMU), N,N,N′,N′-tetramethylurea (TMU), and N,N′-dimethylpropyleneurea (DMPU: IUPAC name 1,3-dimethyltetrahydropyrimidin-2(1H)-one). The equilibrium molecular geometry of DMU (all three conformers), TMU, and DMPU and the frequencies, intensities, and depolarization ratios of their fundamental infrared (IR) and Raman vibrational transitions were obtained by DFT calculations. The vibrational spectra were fully analyzed by normal coordinate methods as well. A starting force field for DMPU was obtained by adapting corresponding force constants for DMU and TMU, resulting after refinements in the stretching force constants C=O (7.69, 7.30, 7.68 N·cm?1), C–N (5.16, 5.55, 5.05 N·cm?1), and C-Me (5.93, 4.00, 4.22 N·cm?1) for DMU, TMU, and DMPU, respectively. The dominating conformer of liquid DMU was identified as trans-trans, strong intermolecular hydrogen bonding was verified in solid DMU, and weak dipole–dipole association was found in liquid TMU and in DMPU. Special attention was paid to analyzing the methyl group frequencies, which revealed deviations from local C3v symmetry. A linear correlation was found between the CH stretching force constants and the inverse of the CH bond lengths (1/r 2). The averaged NH stretching frequencies of gaseous, dissolved, and solid urea and of DMU, with variations for hydrogen bonding of different strength, are linearly correlated to the NH stretching force constants. Characteristic skeletal vibrations were assigned for a broad variety of urea derivatives and also for pyrimidine derivatives, which all contain the N2C=O entity. The very strong IR bands of C=O stretching (1,676 ± 40 cm?1) and asymmetric CN2 stretching (1,478 ± 60 cm?1), and the very intense Raman feature of symmetric CN2 stretching or ring breathing (757 ± 80 cm?1), can be recognized as fingerprint bands also for the pyrimidine derivatives cytosine, thymine, and uracil, which all are nucleobases in DNA and RNA nucleotides. 相似文献
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Abstract The 220 MHz 1H nmr spectra of the title compounds (1a) and (2a), respectively, at low temperature in CDCl3 solution are interpreted in terms of two interconverting chair forms with unequal populations (Ke = 1.17, δG° ~70 cals/mole for 1a and Ke = 1.8, δG° ~0.2 kcal/mole for 2a at ?30°C). A strong intramolecular OH…S hydrogen bond in both compounds reduces the number of degrees of freedom of the bulky N-thiobenzoyl substituent, which nearly eclipses the equatorial α-CH2 hydrogen atoms in both comformations. Steric interactions between the 6′ phenyl proton and the hetero-ring α-CH2 protons trans to the thiocarbonyl group are different in the two conformations of la and 2a. 相似文献
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New eight lanthanide metal complexes were prepared. These complexes were characterized by elemental analysis, molar conductivity measurements, spectral analysis (1H NMR, FT-IR, UV–vis), luminescence and thermal gravimetric analysis. All Ln(III) complexes were 1:1 electrolytes as established by their molar conductivities. The microanalysis and spectroscopic analysis revealed eight-coordinated environments around lanthanide ions with two nitrate ligands behaving in a bidentate manner. The other four positions were found to be occupied with tetradentate LIII ligand. Tb–LIII and Sm–LIII complexes exhibited characteristic luminescence emissions of the central metal ions and this was attributed to efficient energy transfer from the ligand to the metal center. The LIII and Ln–LIII complexes showed antibacterial activity against a number of pathogenic bacteria. 相似文献
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N. K. Singh M. Singh P. Tripathi A. K. Srivastava M. J. K. Thomas 《Hyperfine Interactions》2008,185(1-3):133-137
A new series of iron(III) complexes [Fe(L1)(HL1)], [Fe(L1)Cl]; [H2L1 = N′-(2-methoxythiobenzoyl)pyridine-2-carbohydrazide], [Fe(L2)(acac)], [Fe(HL2)2Cl]; [H2L2 = N′-(4-methoxythiobenzoyl)pyridine-2-carbohydrazide] and [Fe(L3) (acac)]; [H2L3 = N′-(2-hydroxythiobenzoyl)pyridine-2-carbohydrazide] were prepared by stirring/refluxing/mixing the respective ligand with FeCl3/Fe(acac)3 in chloroform/methanol. All the compounds were characterized by elemental analyses, magnetic susceptibility, IR, UV and Mössbauer spectral data. The complexes posses high/ low spin state and have tetrahedral/octahedral geometry. 相似文献
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We studied the properties of the emission, absorption and excitation of dual fluorescence of (N,N′?dimethylamino)benzonitrile in a polar aprotic solvent acetonitrile under selective irradiation of solutions by light with different energies of quanta to elucidate mechanisms of dual fluorescence arising in this solvent at different temperatures in the range 274–313 K. In all cases, dual fluorescence of the solute in acetonitrile was observed, which is caused by emission from locally excited Franck-Condon and charge-transfer states. A change in the energy of excitation quanta has a weak effect on the position of the fluorescence bands; however, the intensity ratio between the bands noticeably changes in favour of the intensity of the long-wavelength band at excitation in the range of the long-wavelength absorption band. An interesting and unusual fact is that solution heating is accompanied by essential growth of quantum yield of dual fluorescence at all wavelengths of the excitation. To explain the observed effects, the same dependences were measured and analysed for DMABN in neutral solvent n-hexane in the same conditions. We involve also the data of quantum-mechanical calculations, which show that there is a considerable probability of occurrence in solutions of DMABN rotational isomers with differing orientation of the dimethylamino group with respect to the benzonitrile. In the excited state, these have different charge-transfer rates, resulting in a modulation in the intensity ratio of the observed fluorescence bands with change excitation energy quanta on the red wing of the absorption band, doi: 10.1134/S0030400X12050219. 相似文献
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Single crystal E.P.R. and cobalt ENDOR measurements on N,N′-ethylenebis(acetylacetonatiminato)Co(II), Coacacen, diluted in Niacacen·1/2 H2O are reported. Forbidden Δm Co = 1,2 transitions in the E.P.R. spectra have been observed. The g-tensor (E.P.R.) and the cobalt hyperfine and quadrupole tensors (ENDOR) have been determined. The g- and cobalt hyperfine tensors are discussed. They support the |2 A 2,yz? groundstate proposed for four coordinated low-spin Schiff base complexes of cobalt(II). The measured quadrupole coupling is also compatible with a |2 A 2,yz? groundstate, if anisotropic contraction of the cobalt 3d orbitals is taken into consideration. 相似文献
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Rudolf Rodenberg 《Zeitschrift für Physik A Hadrons and Nuclei》1961,162(4):347-357
The ratio of the differential cross section for the (e, N)-process to the total (γ,N) -cross section is derived with the use of the relativistic Coulomb Eigenfunctions for the continuous spectrum. For electric and magnetic dipole transitions the Born approximation, the Coulomb correction, the effect of screening and that of finite nuclear size are calculated. In this angular distribution there should be no interference of electron waves scattered by different multipoles, where the inelastically scattered electrons are detected. Numerical calculations have been done for nuclei withZ=6, 29, and 82 and scattering anglesθ=1Ω, 132Ω, 160Ω and 180Ω of the electron. The result of this theory is compared with the experiments of W.C.Barber et al. 相似文献
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In a previous paper1 the infrared spectra of some chelates of the type N,N′-ethylenebis(acetylacetoneiminato)-metal(II) were reported and the vibrational assignments were made on a correlative basis and with the aid of the results of a normal coordinate treatment. In order to provide further data for a more reliable assignment of the vibrational spectra of this class of metal chelates an investigation was carried out on the infrared pleochroism of the single crystals of N,N′-ethylenebis(acetylacetoneiminato)-copper(II) (CuBae.1/2H20 in the following). 相似文献
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Bo Jiao Zhaoxin Wu Xingwei Yan Xun Hou 《Applied Physics A: Materials Science & Processing》2010,98(1):239-243
We investigated the influence of the thickness of hole-transport layer, N,N′-biphenyl-N,N′-bis(1-naphthyl)-(1,1′-biphenyl)-4,4′-diamine (NPB), on the performance of the typical bi-layer organic light-emitting diodes
(OLEDs). It was found that both the current efficiency and the power efficiency of bi-layer OLEDs were improved when the thickness
of the hole-transport layer varied from 30 to 120 nm. By investigating the hole-injection efficiency of ITO/NPB contact with
various thicknesses of NPB film, we found that the hole-injection efficiency was reduced with the thickness of NPB layer increasing
from 60 to 180 nm, which improved the injected carriers balance in devices and increased the efficiency of the bi-layer OLEDs. 相似文献
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用密度泛函方法,在ROB3LYP/SDD//ROB3LYP/LANL2MB水平上,对Cu(Ⅱ)-Co(Ⅱ)异双核配合物进行了理论计算,优化得到了它的单、三重态的平衡几何构型,计算了它们的谐振动频率.结果表明:该配合物分子的三重态比单重态稳定,电子自旋布居高度集中在Cu和Co原子上,体系中存在较弱的自旋离域效应.体系的前线分子轨道主要由Cu和Co原子的d轨道和配体原子的p轨道构成,这种构成有利于配体原子与Cu、Co原子之间的电子转移.期望这些研究为这类配合物的合成及分子组装分析研究提供理论参考. 相似文献
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Five novel lanthanide (Eu3+, Tb3+, Gd3+, Sm3+ and Dy3+) complexes with 2, 2'-bipyridine-N, N'-dioxide (bipyO2) were synthesized and characterized by elemental analysis, IR spectrum. The triplet state energy of bipy O2 was determined to be 22275 cm(-1) with the phosphorescence spectrum of bipy O2 and its gadolinium complex. The photophysical properties of these complexes indicated that the triplet state energy of the ligand is suitable for the sensitization of the luminescence of Eu3+, Tb3+, Sm3+ and Dy3+, especially of Tb3+. 相似文献
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PS(PerfectShuffle)opticalinterconnectioncancomposedvariousopticalinterconnectionnetworks,forexampleΩnetwork.However,itsconver... 相似文献
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Shao Changgui Xu Bangqing Guo Youzhong 《International Journal of Theoretical Physics》1986,25(9):945-957
We establish a superspaceU for supergauge actions, a conformal supergroupSU(2,2¦N), and a conformal extendedSU(2,2¦N) supergravity theory. Using the Lagrangian Higgs evolution mechanism under the supergroupSU(2,2¦N) SU(N) acting on the superspaceU, we advance anSU(2,2¦N)SUN superunified theory of a superunited system, discuss the Lagrangian evolution of the superunified theory, and give the fiber bundle geometry of all the above mechanisms. 相似文献