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1.
Biomimetic hydrolysis of DNA or RNA is of increasing importance in biotechnology and medicine. The ability to cleave nucleic acids efficiently, in a non-degradative manner, and with high levels of selectivity for site or structure will be required by many applications for the manipulation of genes, the design of structural probes and the development of novel therapeutics1. There has been much interest in the development of lanthanide complexes as nucleic acid cleavage agents. It has been fou…  相似文献   

2.
Theinteractionofrareearthwithhormoneshouldbestudiedindetailinordertoexploremechanismoftheneuralandendocrineeffectofrareearth.Asacontinuationofourresearchontheinteractionofrareeafthwithhormone',stabilityandluminescencepropertiesofTb(lII)complexeswithadrenalineorepinephrine(3,4-dihydroxy-a(methylaminomethyl)benzylalcohol,(HO)zCeH3CH(OH)CH=NHCHshavebeenstudiedinthiswork.Satisfactoryresultshavebeenobtained.PotentiometrictitrationsweremadeonapHS-3CpHmeterbymeansofthemethoddescribedinpreviou…  相似文献   

3.
IntroductionLanthanidecomplexeshaveattractedmuchattentionbecauseoftheirimportantapplications .1InparticularEu(III)andTb(III)canbecharacterizedbylong lived(mstimescale)andstrongluminescentelectronicallyex citedstates ,whichmakesthemimportantinanalyticalchem…  相似文献   

4.
5.
Using DFT/TDDFT methods,the excited-state lifetimes of Ru(Ⅱ) polypyridyl complexes were computed accurately and the reason of Ru(Ⅱ) polypyridyl complexes with long excited-state lifetimes was explained by the electron-transfer distances and HOMO-LUMO gaps.Finally,the photovoltaic conversion efficiencies of complexes were predicted using DFT and docking methods.This work has provided methods of predicting the excited-state lifetimes and photovoltaic conversion efficiencies of Ru(Ⅱ) polypyridyl complexes.  相似文献   

6.
The formation conditions and luminescence of Tb(III) complexes with synthesized copolymers of unsaturated acetylacetone derivatives with styrene and methyl methacrylate were studied. The luminescence intensity of these Tb(III) complexes was found to depend on the β-diketone substituent nature (CH3, CF3, C6H5) and structure (linear, branched) and the β-diketone to monomer ratio in the polymerizing mixture.  相似文献   

7.
The stability constants and species distributions of complexes of two lanthanide ions, Eu(Ⅲ) and Tb(Ⅲ), with a macrocyclic ligand, BDBPH, in 1:1 and 2:lsystem, were determined potentiometrically at 25.0 ℃ and I=0.100 mol L^-l. The two metal ions could form deprotonated mono- or dinuclear complexes with BDBPH after the first two protons of the ligand completely neutralized. At higher pH values, Eu(Ⅲ) could not form hydroxy complexes with BDBPH, while Tb(Ⅲ) could form hydroxy complexes in the type of M2L(OH), M2L(OH)2, and M2L(OH)3.  相似文献   

8.
MThekeymaterials,5-amino-l,10-phenanthrolineandetS-Ru(phew,CI,,werepreparedbythemethodsofreferences"'.Synthesisofla,foandicEquimolaramountsofcorrespondingto-bromo-alkyIacyIohIondewasaddeddropwisetoasuspensionof5-amino-l,10-phenanthrolineandsodiumdicarbonateindryacetonitrilewithstirringatroomtemperatureundernitrogenfor4-6hours.Thentheresultingsolidwasfilteredandwashedbyacetonitrile,5%sodiumbicarbonateaqueoussolutionandwaterinturn.Afterbeingdriedicvacuo,yellowmicrocrystalsla-cwereobtained.Sy…  相似文献   

9.
Treatment of β-diketiminate ligands bearing different N-aryl monoatomic substituents [HLH = (C6H5)N = C(Me)CH=C(Me)NH(C6H5), HLF = (2,6-F2C6H3)N=C(Me)CH=C(Me)NH(2,6-F2C6H3), and HLCl = (2,6-Cl2C6H3)N=C(Me)CH=C(Me)NH(2,6-Cl2C6H3)] with Ln(CH2SiMe3)3(THF)2 (Ln = Y and Lu) afforded a variety of β-diketiminato rare-earth metal complexes depending on substituents, namely, phenyl ring C–H bond activated complexes (L')(LH)Lu(THF) ( 1b , L' = (C6H4)N = C(Me)CH=C(Me)N(C6H5)), six-coordinate homoleptic complexes (LH)3Ln [Ln = Y ( 1aa ), Lu ( 1bb )], five-coordinate monoalkyl complexes (LF)2Ln(CH2SiMe3) [Ln = Y ( 2a ), Lu ( 2b )], and four-coordinate dialkyl complexes (LCl)Ln(CH2SiMe3)2 [Ln = Y ( 3a ), Lu ( 3b )]. All these complexes were characterized with NMR spectroscopy, and lutetium complexes 1b , 1bb and 3b were structurally validated by single-crystal X-ray diffraction analysis. Moreover, dialkyl complexes 3 promoted the polymerization of 2-vinylpyridine (2-VP) to produce atactic poly(2-vinylpyridine) (P2VP) with quantitative yield. On activation with an equimolar amount of [Ph3C][B(C6F5)4], complexes 3 afforded highly isotactic P2VP with an mm value up to 94 %. Both 1H NMR spectrum and MALDI-TOF mass analysis of an oligomer indicate that the polymerization was initiated by coordination insertion of 2-VP into the Y-CH2SiMe3 bond.  相似文献   

10.
IntroductionDye sensitizedsolarcells (DSSC)havebecomethefocusofmanyinvestigationssinceMichaelGr tzelandco workersmadethedyemoleculesadsorbedonaporousnet workoftheinterconnectednanometer sizedcrystallinesofawidebandgapsemiconductor.1 3Animpressivesolar to electricalenergyconversionefficiencyof 10 %hasbeenre portedanditmakespracticalapplicationfeasible .4 Thissystemconsistsofadye coatedsemiconductorelectrodeandacounterelectrodearrangedinasandwichconfigura tionandtheinter electrodespaceisfilled…  相似文献   

11.
1INTRODUCTIONMacrocyclicdioxotetramineswithvariousfunctionalpendantshavereceivedmuchat tention,theintroductionofvariousadditi...  相似文献   

12.
In this paper, surface photovoltage technique (SPV) was applied to the study of photovoltaic and gas sensitive properties of TCNQ polycrystal. It was found that SPV shows two peaks at 390 nm(P1) and 480 nm (P2) in the ultraviolet-visible range. And they are opposite in phase. The results of gaseous adsorption confirm that P, shows the acceptor characteristics, while PI shows that of donor. During adsorption, donor gas interacts with conjugated II * orbital, acceptor gas with the terminal group C=N .  相似文献   

13.
Density functional theory B3LYP method and second-order Moller-Plesset perturbation theory MP2 method were employed to obtain the optimized geometries of the ground state and interaction energy for diazines and water complexes. The results show that the ground state complexes have strong hydrogen bonding interaction with -20.99, -16.73 and -15.31 kJ/mol after basis set superposition error and zero-point vibration energy correction for pyridazine-water, pyrimidine-water and pyrazine-water, respectively, and large red-shift for the symmetric H-O stretching vibration frequencies due to the formation of N…H-O hydrogen bond in the diazine-water complexes. The NBO analysis indicates that intermolecular charge transfer are 0.0316, 0.0255 and 0.0265 e respectively. In addition, the first singlet (n,n*) vertical excitation energy of the monomer and the hydrogen bonding complexes between diazines and water was investigated by time-dependent density functional theory.  相似文献   

14.

The benzoylated asymmetrical nickel(II) complexes, 2,4,9,11-tetramethyl-3,10-dibenzoyl-1,5,8,12-([14]-Xbenzo)tetraazacyclotetradecinato(2-)nickel(II) ( A1-4) and 2,4,10,12-tetramethyl-3,11-dibenzoyl-1,5,9,13-([15]-Xbenzo)tetraazacyclotetradecinato(2-)nickel(II) (B1-4), wherein X = CH3(A1 and B1), H ( A2 and B2), Cl (A3 and B3) and NO2(A4 and B4), have been synthesized and characterized by analysis, IR, electronic, 1H- and 13C-NMR spectra. An intense IR band due to C=O stretching is present in the range 1630-1650 cm-1 upon benzoylation. Electronic spectra show bands at 375-390 nm with kmax = 10000-26000 M-1cm-1 due to π→π* transitions of macrocycles and at 500-550 nm with kmax = 1000-5000 M-1cm-1 attributable to LMCT for each of the complexes. The proton peaks of methine sites in the NMR spectra disappear on benzoylation. Results of the carbon-13 NMR spectra are compatible with those of the proton NMR. Cyclic voltammograms of the complexes in acetonitrile exhibit two successive and reversible (irreversible in DMSO) oxidation peaks for the macrocycle (Mc M Mc ” + and Mc ” + M Mc 2+) in the ranges +0.31 - +0.51 and +0.60 - +0.84 V, respectively. In the reduction area, a reversible wave is followed by reduction of metal {Ni(II) M Ni(I) at around m 2.32 V}. Unlike analogous complexes without the benzoyl group, those compounds are not electropolymerized by cyclic voltammetry.  相似文献   

15.
The synthesis of phase-pure ternary solutions of tetradymite-type materials (BixSb1−x)2Te3 (x=0.25; 0.50; 0.75) in an ionic liquid approach has been carried out. The nanoparticles are characterized by means of energy-dispersive X-ray spectroscopy (EDX), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy. In addition, the role of different processing approaches on the thermoelectric properties - Seebeck coefficient as well as electrical and thermal conductivity - is demonstrated.  相似文献   

16.
张剑  唐瑜 《中国化学》2002,20(9):909-912
Two new amide type podands L1 and L2 (L1=1,1,1-tris{[2-benzylaminoformyl)phenoxyl] methyl} propane,L2=1,3,5-timethyl-2,4,6-tris{[2-benzylaminoformyl)phenoxyl]methyl} benzene)and their europium and terbium nitrates complexes were synthesized.The luminescence properties of these complexes were also studied.  相似文献   

17.
IntroductionThecontroleddesignofsolid-statearchitecturesandcrystalengineeringhascurrentlybeenrecognizedasoneofthemostimportan...  相似文献   

18.
《结构化学》2019,38(11)
Two 3D rare earth coordination polymers {[Ho(ptc)(H_2O)_(2.5)]·0.5 H_2O}n(1) and {[Y2(ptc)2(H_2O)_5]·H_2O}n(2)(H_3ptc = 2,4,6-pyridinetricarboxylic acid) have been synthesized with Ho(Ⅲ) or Y(Ⅲ) chloride and H_3ptc by hydrothermal method. The X-ray structure analyses display the two complexes are isomorphic and crystallize in monoclinic crystal system with P21/n space group for 1 and P21/c space group for 2. Ho(Ⅲ) and Y(Ⅲ) both show two different coordination modes. One is nine-coordinated and forms a distorted tricapped trigonal prism and the other is eight-coordinated to get a distorted bicapped trigonal prism. The ptc3-also shows two different coordination modes by connecting four or three rare earth ions. The photoluminescent properties of 2 show that it can emit blue fluorescence at 440 nm with excitation at 335 nm. The fluorescence lifetime of 2 is 1.64 μs and the absolute fluorescence quantum yield is 10.2%.  相似文献   

19.
将不同荧光性能的铽(Tb)、镨(Pr)离子分别与铕(Eu)离子混合,以三异丙氧基稀土的形式掺杂P(MMA-CO-St)共聚物,研究Eu^3 /Tb^3 和Eu^3 /pr^3 共掺杂P(MMA-CO-St)的荧光性能的变化情况.结果表明,Eu^3 /Tb^3 掺杂的P(MMA-CO-St)中,Tb^3 作为能量给予体,Eu^3 作为能量接受体,能量转移的结果使Eu^3 特征荧光显增强;Eu^3 /pr^3 掺杂的P(MMA-CO-St)中,Eu^3 的能量向pr^3 转移,致使Eu^3 的特征荧光猝灭,pr^3 的荧光略为增强.  相似文献   

20.
To investigate the effect of ligand remote (>10 Å) substituents on the bridging metal center on the metal-to-metal charge transfer (MMCT) properties in cyanidometa-bridged complexes, a series of new cyanidometal-bridged complexes and their one-electron and two-electron oxidation products have been synthesized and well characterized (namely, trans-[Cp(dppe)Fe−NC−(L)Ru(PPh3)−CN−Fe(dppe)Cp][PF6]n (n=2, 3, 4) (L=dmptpy, 1[PF6]n ; L=meoptpy, 2[PF6]n ; L=t-Buptpy, 3[PF6]n ) (Cp=1,3-cyclopentadiene, dppe=1,2-bis(diphenylphosphino)ethane, PPh3=triphenylphosphine, dmptpy=4′-(4-dimethylaminophenyl)-2,2′,6′,2′′-terpyridine, meoptpy=4′-(4-methoxyphenyl)-2,2′,6′,2′′-terpyridine, t-Buptpy=4′-(4-tertbutylphenyl)-2,2′,6′,2′′-terpyridine)). The investigations suggest that the cyanido-stretching (νCN) vibration energy for the complexes is unsensitive to the electron-donating ability change of the remote substituents of the cyanidometal bridging auxiliary ligand from tertbutyl, methoxy to dimethylamino group. However, the MMCT energies of the one- and two-electron oxidation complexes are still sensitive to the remote substituents of the ligand on the bridging metal center, and decreases with the increase of the electron-donating ability of the remote substituents from tertbutyl, methoxy to dimethylamino group. All one-electron and two-electron oxidation products belong to Class II mixed valence compounds according to the classification of Robin and Day.  相似文献   

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