共查询到20条相似文献,搜索用时 15 毫秒
1.
Grégory Nocton Aline Nonat Christelle Gateau Marinella Mazzanti 《Helvetica chimica acta》2009,92(11):2257-2273
A series of europium(III) and terbium(III) complexes of three 1,4,7‐triazacyclononane‐based pyridine containing ligands were synthesized. The three ligands differ from each other in the substitution of the pyridine pendant arm, namely they have a carboxylic acid, an ethylamide, or an ethyl ester substituent, i.e., these ligands are 6,6′,6″‐[1,4,7‐triazacyclononane‐1,4,7‐triyltris(methylene)]tris[pyridine‐2‐carboxylic acid] (H3tpatcn), ‐tris[pyridine‐2‐carboxamide] (tpatcnam), and ‐tris[pyridine‐2‐carboxylic acid] triethyl ester (tpatcnes) respectively. The quantum yields of both the europium(III) and terbium(III) emission, upon ligand excitation, were highly dependent upon ligand substitution, with a ca. 50‐fold decrease for the carboxamide derivative in comparison to the picolinic acid (=pyridine‐2‐carboxylic acid) based ligand. Detailed analysis of the radiative rate constants and the energy of the triplet states for the three ligand systems revealed a less efficient energy transfer for the carboxamide‐based systems. The stability of the three ligand systems in H2O was investigated. Although hydrolysis of the ethyl ester occurred in H2O for the [Ln(tpatcnes)](OTf)3 complexes, the tripositive [Ln(tpatcnam)](OTf)3 complexes and the neutral [Ln(tpatcn)] complexes showed high stability in H2O which makes them suitable for application in biological media. The [Tb(tpatcn)] complex formed easily in H2O and was thermodynamically stable at physiological pH (pTb 14.9), whereas the [Ln(tpatcnam)](OTf)3 complexes showed a very high kinetic stability in H2O, and once prepared in organic solvents, remained undissociated in H2O. 相似文献
2.
Hyounsoo Uh Paul D. Badger Steven J. Geib Stéphane Petoud 《Helvetica chimica acta》2009,92(11):2313-2329
A series of free ligands, H2 L 1 , H2 L 2 , H2 L 3 , and H2 L 4 , designed for the coordination and sensitization of near‐infrared(NIR)‐emitting Nd3+ were synthesized by modifying the salophen Schiff base with different numbers and locations of Br‐substituents. The nature of the Nd3+ complexes in solution was determined to be [ML2]? by spectrophotometric titrations as an indication that the different substituents do not affect significantly the nature of the formed species. The structures were determined in the solid phase from X‐ray diffraction experiments. The stoichiometries and structures in the solid state are different from those observed in solution. We established that the structures in the solid state can be partially controlled by the crystallization conditions. The ligands L 1 – L 4 have the ability to sensitize Nd3+ through intramolecular energy transfer from the ligand to the metal ion. We quantified that the numbers and locations of Br‐substituents control the emitted luminescence intensity of the complex by the heavy‐atom effect. 相似文献
3.
Zhi‐Wen Nie Sha‐Sha Li Cheng‐Hui Zeng Lei Wang Yuan Li Shun‐Gao Yin Sheng‐Liang Zhong 《无机化学与普通化学杂志》2014,640(11):2255-2260
[TbNa(4‐msal)4(phen)2]n ( 1 ) (4‐msal = 4‐methyl salicylic acid), a new hetero‐metallic lanthanide coordination polymer (CP) involving sodium was synthesized. It crystallizes in the monoclinic space group P21/n, with a = 20.4809(9) Å, b = 9.8183(2) Å, c = 26.1987(11) Å, α = 90.00°, β = 112.922(5)°, γ = 90.00°, V = 4852.2(3) Å3, and Z = 4. The complex was characterized by single crystal and powder X‐ray diffraction, elemental analysis (EA), and Fourier transform infrared (FT‐IR) and luminescence spectroscopy. The luminescence properties of a powder sample of 1 were studied at room temperature and the luminescence lifetime and total quantum yield (QY) were determined. 相似文献
4.
Synthesis,Structures, and Properties of Lanthanide Complexes with Pyrimidine‐2‐carboxylic Acid
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Six lanthanide complexes [Ln(pmc)2NO3]n [Hpmc = pyrimidine‐2‐carboxylic acid, Ln = La ( 1 ), Pr ( 2 )], [Ln(pmc)2(H2O)3]NO3 · H2O [Ln = Eu ( 3 ), Tb ( 4 ) Dy ( 5 ), Er ( 6 )] were synthesized by the reactions of lanthanide nitrate and pyrimidine‐2‐carboxylic acid in water at room temperature. These complexes were characterized by single‐crystal X‐ray diffraction analysis, elemental analysis, IR, circular dichroism (CD) and fluorescence spectra. Structure analysis shows that complexes 1 and 2 are isostructural with P43212 space group, whereas isostructural complexes 3 – 6 belong to the P21/c space group. In complexes 1 and 2 , the central metal atoms are coordinated by nitrates and pmc–, which are self‐assembled to construct a 3D porous network with 62.62.62.62.62.62 (66) topology. In complexes 3 – 6 , H2O and pmc– ligands are coordinated and the complexes exhibit a one‐dimensional zigzag chain, which is further expanded into a 3D structure by hydrogen bonding. In addition, the circular dichroism of 1 and 2 proves that the two complexes are both chiral with achiral ligand of Hpmc. Luminescent measurements of compounds 3 – 5 indicate that the characteristic fluorescence of Eu3+, Tb3+, and Dy3+ are observed. 相似文献
5.
Rui Jia Ting Gao Yu Yang Wenbin Sun Ruoxi Chen Pengfei Yan Guangfeng Hou 《无机化学与普通化学杂志》2015,641(11):1974
The luminescence properties of the tetranuclear bimetallic lanthanide complexes Sm2Eu2 ( 1 ) and Eu2Tb2 ( 2 ), were compared with those of the analogous homometallic complexes [Sm4(μ3‐OH)2(salen)2(acac)6(CH3OH)2] · CH3OH ( 3 ) and [Eu4(μ3‐OH)2(salen)2(acac)6(CH3OH)2] ( 4 ) [H2salen = N, N′‐ethylenebis(salicylideneimine), Hacac = acetylacetonate]. X‐ray crystallographic analysis reveals that complexes 3 and 4 have planar tetranuclear structures. For the Eu2Tb2 configurational isomer, the TbIII ion in complex 2 mainly serves as a sensitizer. The quantum yields and lifetime measurements for 2 support the premise that Ln/Ln energy transfer occurs in such lanthanide bimetallic complexes, along with the usual ligand‐to‐metal triplet energy pathways. Complexes 3 and 4 exhibit the characteristic metal‐centered emission. 相似文献
6.
报道用一步酸化法制得四种未见报道的1:10系列镧系钼钒杂多配合物K7H8LnMo4V6P36.xH2O(Ln=La,Ce,Pr,Nd)。提示元素分析,红外光谱,紫外光谱,X射线粉末衍射及差热-热重分析结果讨论了它们的结构及性质。 相似文献
7.
Anthony D'Aléo Jide Xu King Do Gilles Muller Kenneth N. Raymond 《Helvetica chimica acta》2009,92(11):2439-2460
The synthesis of the cyclen derivative H4 L 1 ?2 HBr containing four 2‐hydroxybenzamide groups is described. The spectroscopic properties of the LnIII conplexes of L 1 (Ln=Gd, Tb, Yb, and Eu) reveal changes of the UV/VIS‐absorption, circular‐dichroism‐absorption, luminescence, and circularly polarized luminescence spectra. It is shown that at least two metal‐complex species are present in solution, whose relative amounts are pH dependent. At pH>8.0, an intense long‐lived emission is observed (for [Tb L 1 ] and [Yb L 1 ]), while at pH<8.0, a weaker, shorter‐lived species predominates. Unconventional LnIII emitters (Pr, Nd, Sm, Dy, and Tm) were sensitized in basic solution, both in the VIS and in the near‐IR, to measure the emission of these ions. 相似文献
8.
Steve Comby Floriana Stomeo Colin P. McCoy Thorfinnur Gunnlaugsson 《Helvetica chimica acta》2009,92(11):2461-2473
The synthesis of the C2‐symmetrical ligand 1 consisting of two naphthalene units connected to two pyridine‐2,6‐dicarboxamide moieties linked by a xylene spacer and the formation of LnIII‐based (Ln=Sm, Eu, Tb, and Lu) dimetallic helicates [Ln2? 1 3] in MeCN by means of a metal‐directed synthesis is described. By analyzing the metal‐induced changes in the absorption and the fluorescence of 1 , the formation of the helicates, and the presence of a second species [Ln2? 1 2] was confirmed by nonlinear‐regression analysis. While significant changes were observed in the photophysical properties of 1 , the most dramatic changes were observed in the metal‐centred lanthanide emissions, upon excitation of the naphthalene antennae. From the changes in the lanthanide emission, we were able to demonstrate that these helicates were formed in high yields (ca. 90% after the addition of 0.6 equiv. of LnIII), with high binding constants, which matched well with that determined from the changes in the absorption spectra. The formation of the LuIII helicate, [Lu2? 1 3], was also investigated for comparison purposes, as we were unable to obtain accurate binding constants from the changes in the fluorescence emission upon formation of [Sm2? 1 3], [Eu2? 1 3], and [Tb2? 1 3]. 相似文献
9.
Novel Lanthanide(III) Ternary Complexes with Naphthoyltrifluoroacetone: A Synthetic and Spectroscopic Study
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Thi‐Nguyet Trieu Thi‐Hien Dinh Hung‐Huy Nguyen Ulrich Abram Minh‐Hai Nguyen 《无机化学与普通化学杂志》2015,641(11):1934-1940
A series of lanthanide complexes with general formula [Ln(NTA)3X] were prapared [Ln = Y ( a ), Er ( b ), Eu ( c ), NTA = naphthoyltrifluoroacetone, X = H2O ( 1 ), phen = phenanthroline ( 2 ), bpyO1 = 2, 2′‐bipyridine N‐oxide ( 3 ), and bpyO2 = 2, 2′‐bipyridine‐N,N′‐dioxide ( 4 )]. The crystal structures of [Eu(NTA)3bpyO2] ( 4b ), [Er(NTA)3bpyO1] ( 3c ), and [Er(NTA)3phen] ( 2c ) were determined. X‐ray crystallographic analysis reveals that the complexes are of mononuclear structure with three NTA and one ancillary ligand. The photoluminescence spectra of 3c and 4b exhibit strong characteristic emissions arising from Eu3+ central ion due to the efficient sensitization of bpyO1 and bpyO2, respectively. 相似文献
10.
Yasuchika Hasegawa Ryo Hieda Tetsuya Nakagawa Tsuyoshi Kawai 《Helvetica chimica acta》2009,92(11):2238-2248
Novel EuIII complexes with bidentate phosphine oxide ligands containing a bipyridine framework, i.e., [3,3′‐bis(diphenylphosphoryl)‐2,2′‐bipyridine]tris(hexafluoroacetylacetonato)europium(III) ([Eu(hfa)3(BIPYPO)]) and [3,3′‐bis(diphenylphosphoryl)‐6,6′‐dimethyl‐2,2′‐bipyridine]tris(hexafluoroacetylacetonato)europium(III) ([Eu(hfa)3(Me‐BIPYPO)]), were synthesized for lanthanide‐based sensor materials having high emission quantum yields and effective chemosensing properties. The emission quantum yields of [Eu(hfa)3(BIPYPO)] and [Eu(hfa)3(Me‐BIPYPO)] were 71 and 73%, respectively. Metal‐ion sensing properties of the EuIII complexes were also studied by measuring the emission spectra of EuIII complexes in the presence of ZnII or CuII ions. The metal‐ion sensing and the photophysical properties of luminescent EuIII complexes with a bidentate phosphine oxide containing 2,2′‐bipyridine framework are demonstrated for the first time. 相似文献
11.
Craig P. Montgomery Elizabeth J. New Lars O. Palsson David Parker Andrei S. Batsanov Laurent Lamarque 《Helvetica chimica acta》2009,92(11):2186-2213
A series of seven emissive europium(III) and terbium(III) complexes was prepared, incorporating a 3‐pyridyl‐4‐azaxanthone or 3‐pyrazolyl‐4‐azaxanthone sensitising moiety within a polydentate macrocyclic ligand. High overall emission quantum yields in aqueous media are attenuated in the presence of protein or certain oxy anions due to displacement of the N,N′‐chelated sensitiser. Nevertheless, these complexes are taken into cells and tend to localise over the first few hours in mitochondria before being trafficked to endosomal compartments. Cell uptake studies, in the presence of competitive inhibitors or promoters of well‐defined uptake pathways, reveal a common uptake mechanism involving macropinocytosis. 相似文献
12.
Michael Andrews Benjamin D. Ward Rebecca H. Laye Benson M. Kariuki Simon J. A. Pope 《Helvetica chimica acta》2009,92(11):2159-2172
The syntheses of the two tetraazamacrocyclic ligands L1 and L2 bearing a [(methoxy‐2‐nitrophenyl)amino]carbonyl chromophore, i.e., an N‐(methoxy‐2‐nitrophenyl)acetamide moiety, together with their corresponding lanthanide‐ion complexes are described. A combined spectroscopic (UV/VIS, 1H‐NMR), structural (X‐ray), and theoretical (DFT) investigation revealed that the absorption properties of the chromophores were dictated by the extent of electronic delocalisation, which in turn was determined by the position of the MeO substituent at the aromatic ring. X‐Ray crystallographic studies showed that when attached to the macrocycle, both isomeric forms of the N‐(methoxy‐2‐nitrophenyl)acetamide unit can participate in coordination, via the C?O, to an encapsulated potassium cation. Luminescence measurements confirmed that such a binding mode also exists in solution for the corresponding lanthanide complexes (q ca. ≤1), with the para‐MeO derivative allowing longer wavelength sensitization (λex 330 nm). 相似文献
13.
《无机化学与普通化学杂志》2018,644(18):1108-1114
Five new 4,5‐dichlorophthalate (dcpa)‐extended lanthanide coordination polymers (CPs) with formulas [Ln2(H2O)(dcpa)3]n (Ln = Tb for 1 , Sm for 2 , Pr for 3 , and Nd for 4 ) and [Yb(H2O)2(dcpa)(Hdcpa)]n ( 5 ) were solvothermally synthesized. Structural determinations demonstrate that CPs 1 – 4 are crystallographically isostructural, exhibiting an infinite two‐dimensional layer with dimeric {Ln2(COO)3} subunits extended by aromatic skeleton of fully deprotonated dcpa2– connectors. In contrast, complex 5 features a one‐dimensional broad ribbon with centrosymmetric {Yb2(COO)2} subunits propagated by pairs of ditopic dcpa2– ligands. Interestingly, the anionic dcpa2– connector can serve as a good antenna ligand to sensitize the characteristic emissions of the different LnIII ions in both the ultraviolet (for 1 – 3 ) and near‐infrared (for 4 and 5 ) regions. 相似文献
14.
Three Isostructural 4‐Sulfophthalate‐Based Lanthanide Complexes: Syntheses,Crystal Structures,and Luminescent Properties
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Three lanthanide complexes with the ligand 4‐sulfophthalate (sp3–), [Ln(H2O)2(sp)]n [Ln = Dy ( 1 ), Tb ( 2 ), and Er ( 3 )], were solvo‐/hydrothermally synthesized by changing the rare earth cations, and were characterized structurally and photophysically. Complexes 1 – 3 are isostructural, exhibiting a two‐dimensional layered structure with centrosymmetric dinuclear subunits infinitely extended by 4‐connected sp3– connectors. Photoluminescence spectra of 1 – 3 demonstrate that anionic sp3– ligand can serve as a functionalized chromophore to sensitize the luminescent emission of the lanthanide ion, suggesting that the sp3–‐involved lanthanide complexes can be used as novel optical materials. 相似文献
15.
Nandu Bala Sharma Anirudh Singh Ram C. Mehrotra† 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1527-1539
The interaction of Bu2Sn(OPri)2 with a trifunctional tetradentate Schiff base (LH3) (where H3L = HOC6H4CH═NCH3C(CH2OH)2) yields the precursor complex Bu2Sn(LH) 1, which, on equimolar reactions with different metal alkoxides [Al(OPri)3, Bu3Sn(OPri), Ge(OEt)4]; Al(Medea)(OPri) (where Medea = CH3N- (CH2CH2O)2); and Me3SiCl in the presence of Et3N], affords, respectively, the complexes Bu2Sn(L)Al(OPri)2 2, Bu2Sn(L)Al(Medea) 3, Bu2Sn(L)Bu3Sn 4, Bu2Sn(L)Ge(OEt)3 5, and Bu2Sn(L)SiMe3 6. The reactions of 2 with 2,5-dimethyl-2,5-hexanediol in a 1:1 ratio and with acetylacetone (acacH) in a 1:2 molar ratio afforded derivatives Bu2Sn(L)Al(OC(CH3)2CH2CH2C(CH3)2 O) 7 and Bu2Sn(L)Al(acac)2 8, respectively. All of the derivatives 1– 8 have been characterized by elemental analyses, molecular weight measurements, and spectroscopic [IR and NMR (1H, 119Sn, 29Si, and 27Al)] studies. 相似文献
16.
Three novel lanthanide complexes [Ln(3,4-DEOBA)3phen]2[Ln=Eu(1), Tb(2), Dy(3); 3,4-DEOBA=3,4- diethoxybenzoate; phen=1,10-phenanthroline] were synthesized and characterized by elemental analysis, molar conductance, X-ray diffraction and infrared spectrometry. The luminescence spectra of complexes 1 and 2 show the characteristic emission of Eu3+ ion(5D0→7F0-3) and Tb3+ ion(5D4→7F6-3). The thermal decomposition mechanism of the title complexes and the analysis of the evolved gases were investigated by thermogravimetry/differential scanning calorimetry-Fourier transform infrared(TG/DSC-FTIR) technology. The results indicate the complexes are thermally stable. In the thermal decomposition of the complexes, phen molecules lost firstly, and then 3,4-DEOBA ligand decomposed into H2O, CO2 and other gaseous molecules. Besides, several gaseous organic fragments were also detected. The heat capacities of complexes 1―3 were measured by DSC in a temperature range of 263.15―340.15 K. Based on the fitted polynomial and thermodynamic equations, the smoothed heat capacities and thermodynamic functions of the three complexes were calculated. The study on biological activity showed that the complexes exhibited good antibacterial activity against Candida albicans, Staphylococcus aureus and Escherichia coli. 相似文献
17.
《Helvetica chimica acta》2017,100(4)
Heavy metal complexes exhibit high phosphorescent efficiency and have been used extensively for electrophosphorescent emitters in the past 16 years. In 2006, we initially reported the use of the popular ligand, 8‐hydroxyquinoline (Q) to coordinate with the heavy metal ions and obtained the red‐infrared phosphorescent emission. In this paper, 8‐hydroxyquinoline has been modified at the 5‐position by electron‐donating and attracting groups and platinum complexes based on 2‐phenylpyridine and 8‐hydroxyquinoline derivatives were synthesized. The electron‐withdrawing group CF 3 and NO 2 lowers the HOMO level of the Q ligand and results in a N^O centered enhanced red‐infrared phosphorescence emission. The complex with CF 3 modification exhibits the highest phosphorescence quantum yield in solid state with a life time of 1.17 μs. 相似文献
18.
Takuya Nishioka Yuji Yamamoto Kimikazu Hashino Kazuko Matsumoto 《Helvetica chimica acta》2009,92(11):2357-2374
Two chelate ligands for europium(III) having minocycline (=(4S,4aS,5aR,12aS)‐4,7‐bis(dimethylamino)‐1,4,4a,5,5a,6,11,12a‐octahydro‐3,10,12,12a‐tetrahydroxy‐1,11‐dioxonaphthacene‐2‐carboxamide; 5 ) as a VIS‐light‐absorbing group were synthesized as possible VIS‐light‐excitable stable Eu3+ complexes for protein labeling. The 9‐amino derivative 7 of minocycline was treated with H6TTHA (=triethylenetetraminehexaacetic acid=3,6,9,12‐tetrakis(carboxymethyl)‐3,6,9,12‐tetraazatetradecanedioic acid) or H5DTPA (=diethylenetriaminepentaacetic acid=N,N‐bis{2‐[bis(carboxymethyl)amino]ethyl}glycine) to link the polycarboxylic acids to minocycline. One of the Eu3+ chelates, [Eu3+(minocycline‐TTHA)] ( 13 ), is moderately luminescent in H2O by excitation at 395 nm, whereas [Eu3+(minocycline‐DTPA)] ( 9 ) was not luminescent by excitation at the same wavelength. The luminescence and the excitation spectra of [Eu3+(minocycline‐TTHA)] ( 13 ) showed that, different from other luminescent EuIII chelate complexes, the emission at 615 nm is caused via direct excitation of the Eu3+ ion, and the chelate ligand is not involved in the excitation of Eu3+. However, the ligand seems to act for the prevention of quenching of the Eu3+ emission by H2O. The fact that the excitation spectrum of [Eu3+(minocycline‐TTHA)] is almost identical with the absorption spectrum of Eu3+ aqua ion supports such an excitation mechanism. The high stability of the complexes of [Eu3+(minocycline‐DTPA)] ( 9 ) and [Eu3+(minocycline‐TTHA)] ( 13 ) was confirmed by UV‐absorption semi‐quantitative titrations of H4(minocycline‐DTPA) ( 8 ) and H5(minocycline‐TTHA) ( 12 ) with Eu3+. The titrations suggested also that an 1 : 1 ligand Eu3+ complex is formed from 12 , whereas an 1 : 2 complex was formed from 8 minocycline‐DTPA. The H5(minocycline‐TTHA) ( 12 ) was successfully conjugated to streptavidin (SA) (Scheme 5), and thus the applicability of the corresponding Eu3+ complex to label a protein was established. 相似文献
19.
通过三茂基镧系化合物Cp_3Ln(Cp=C_5H_5;Ln=Sm,Dy,Ho)与8-羟基喹啉反应(HL),合成了3种新的镧系金属有机化合物,通式为Cp_2LnL(Ln=Sm,Dy,Ho)。经元素分析、红外光谱、X光电子能谱、质谱及分子量测定,推断化合物具有二聚体结构,分子内存在通过喹啉氮原子和氧原子与金属配位而形成的五元螯合环。对化合物的热稳定性进行了研究和比较,发现化合物Cp_2SmL对热不稳定,在180℃以上分解为Cp_3Sm和SmL_3。 相似文献
20.
Michelle Sternberg Jörg Rust Christian W. Lehmann Fabian Mohr 《Helvetica chimica acta》2013,96(2):280-288
Two glucose‐derived thiourea derivatives, 2a and 2b , were prepared by addition of the corresponding amino sugars to a solution of 4‐nitrobenzoyl isothiocyanate (Scheme 1). The thioureas were isolated as colorless solids in good yields and were fully characterized by NMR spectroscopy, optical rotation, elemental analysis, and also by single‐crystal X‐ray diffraction. Attempts to obtain CuII and NiII bis(chelate) complexes with these thioureas failed. However, the C(1)‐protected thiourea derivative 2a reacted with orthopalladated acetato‐bridged dimers to afford the corresponding monomeric PdII complexes 3 and 4 (Scheme 2). In these compounds, the thiourea coordinates to the metal as monoanionic O,S chelate ligand, which was confirmed by X‐ray crystallography. 相似文献