首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
Two novel lanthanide coordination polymers [Sm(Hdipic)(dipic)(H2O)2·4H2O]n (1) (H2dipic=2,6-pyridinedicarboxylic acid) and [Dy(Hdinic)(dinic)(phen)(H2O)·H2O]n (2) (H2dinic=2,5-pyridinedicarboxylic acid) have been synthesized under hydrothermal condition and characterized by single-crystal X-ray diffraction. The results reveal that both of them form a chain-like one-dimensional structure. The photophysical properties for the two complexes have been also reported. Complex 1 shows the characteristic luminescence of central Sm3+ while complex 2 exhibits the particular emission ascribed H2dinic ligands, which suggest the different energy transfer process takes place.  相似文献   

2.
Trichlorides of the lanthanide elements Ln=Ce–Lu form: (a) isotypic hexahydrates LnCl3·6H2O with a coordination number (CN) 8 for the Ln3+ ions. (b) Two isotypic groups of trihydrates LnCl3·3H2O, in the first group Ln=Ce-Dy the CN is 8; the structure of the second group Ln=Er–Lu is unknown. With Ho no trihydrate exists; a dihydrate is formed. (c) Two isotypic groups of monohydrates LnCl3·H2O with unknown structure – Ln=Ce–Dy and Ln=Ho–Lu. For all compounds and for anhydrous chlorides LnCl3 solution enthalpies were measured with an isoperibolic calorimeter. The ΔsolH0 values do not depend only on the difference (lattice enthalpies/hydration enthalpies), but also on the state in solution. According to Spedding the CN of the Ln3+ ions against water changes from 9 to 8 between Nd and Sm, causing minima in the series of solution enthalpies. Dihydrates LnCl3·2H2O are found for Ln=Ce, Pr, Nd, Sm and presumably for Eu and Gd. They are not yet well characterised.  相似文献   

3.
Two new lanthanide coordination polymers with mixed-carboxylates, [Ln(OX)(HAPA)(H2O)]n[Ln = Eu (1), Ho (2); H2APA = 5-aminoisophthalic acid; OX = oxalate] were obtained by hydrothermal reactions, and characterized by single crystal X-ray diffraction, elemental analysis and IR spectra. Complexes 1 and 2 are both 3-D supramolecular structure, in which lanthanide ions are bridged by oxalate and 5-aminoisophthalate ligands forming 2-D metal–organic framework, and 2-D networks are further architectured to form 3-D supramolecular structures by hydrogen bonds. The two carboxylate groups of H2APA ligand are all deprotonated and exhibit chelating and bridging bidentate coordination modes, respectively, and the amino group in HAPA presents – in the titled complexes. The thermogravimetric analysis was carried out to examine the thermal stability of the titled complexes. And the photoluminescence property of 1 was investigated.  相似文献   

4.
李娜  常泽  卜显和 《应用化学》2017,34(9):1046-1051
镧系金属配位聚合物因其独特的组成、结构和性质被广泛应用于荧光识别检测性质研究,但其功能导向构筑依然具有挑战性。本文基于双功能基团配体构筑策略构筑了一例Tb~(3+)配位聚合物[Tb(TZI)(DMF)_2(H_2O)]·(H_2O)(1)((H_3TZI=5-(1-氢-5-四唑基)间苯二甲酸,DMF=N,N-二甲基甲酰胺)),在对其进行详细结构表征的基础上研究了其金属离子识别检测性质。结果表明,基于羧酸和四唑基团与Tb~(3+)离子配位能力的不同,在确保Tb~(3+)配位聚合物成功构筑的同时可将四唑作为识别位点引入配位聚合物框架,使得配合物1可展现出基于金属离子与四唑功能位点配位导致的荧光增强,可实现对Zn~(2+)和Na~+离子的识别检测。本文所报道的结果可为镧系金属配位聚合物的荧光识别检测性质导向构筑提供有价值的参考。  相似文献   

5.
The X-ray crystallographic studies are reported for the water-soluble trivalent lanthanide complexes of the macrocyclic p-sulfonatothiacalix[4]arene [Gd(H2O)6((CH3)2SO)(p-sulfonatothiacalix[4]arene)]·H3O+·5H2O (1) and Na[Nd(H2O)6((CH3)2SO)(p-sulfonatothiacalix[4]arene)]·3H2O (2). The complexes are isostructural and belong to monoclinic system, C2/m space group. The Ln3+ metal ion is coordinated by the thiacalixarene ligand via the sulfonato group, and also ligated by an oxygen atom of a dimethyl sulfoxide (DMSO) molecule that occupies the cavity of the thiacalixarene and six aqua ligands. The thiacalixarenes are linked by the coordinated water molecules through hydrogen bonding to form a 2D polymer. The p-sulfonatothiacalixarenes maintain the clay-like bi-layer structure in the coordination network.  相似文献   

6.
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(5D07F0-3) and Tb3+ ion(5D47F6-3). 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   

7.
A new family of heteropolytungstate complexes (NH4)21[Ln(H2O)5{Ni(H2O)}2As4W40O140xH2O(Ln=Y, Ce, Pr, Nd, Sm, Eu, Gd) were prepared by the reaction of Na27[NaAs4W40O140]·60H2O with NiCl2·6H2O and Ln(NO3)3·xH2O at pH≈4.5. The crystal structures of (NH4)21[Gd(H2O)5{Ni(H2O)}2As4W40O140]·51H2O was determined by X-ray diffraction analysis and element analysis. The compound crystallizes in the monoclinic space group P21/n with a=19.754(3), b=24.298(4), c=39.350(6) Å, β=100.612(3)°, V=18564(5) Å3, Z=2, R1(wR2)=0.0544(0.0691). The central site S1 and two opposite sites S2 of the big cyclic ligand [As4W40O140]28− are occupied by one Ln3+and two Ni2+, respectively, each site supply four Od coordinating to metal ion, another one water molecule and other five water molecules coordinate, respectively, to Ni2+and Ln3+. Polyanion [Ln(H2O)5{Ni(H2O)}2As4W40O140]21− has C2v symmetry. IR and UV–vis spectra of [NaAs4W40O140]27− of the title compounds are discussed.  相似文献   

8.
Lewis acid/base addition between Ln(NO3)3 · 6H2O (Ln = Pr, Nd, Sm, Eu, Tb and Lu) and H2salen [H2salen = N,N′-ethylenebis(salicylideneimine)] gives rise to an array of coordination polymeric structures. Crystal structural analysis reveals that Salen effectively functions as a bridging ligand in these compounds. The size of the lanthanide ions controls the structures of these Salen lanthanide complexes. Two representative structures with one dimensional and two dimensional topologies, viz. [Pr(H2salen)(NO3)3(CH3OH)2]n (1) and [Ln(H2salen)1.5(NO3)3]n [Ln = Pr (2), Nd (3), Sm (4), Eu (5), Tb (6) and Lu (7)] are reported. Luminescent spectra of complexes 4 and 5 exhibit characteristic metal-centered emission lines. However, the characteristic luminescence of the terbium(III) ion is not observed either in solution or in the solid state of complex 6.  相似文献   

9.
Four lanthanide coordination polymers, LaL3(H2O)2(1), LnL23-OH)(H2O)[Ln=Eu(2),Tb(3)] and ErL3·2H2O(4) were synthesized via hydrothermal reactions of lanthanide oxide with 4-pyridin-4-ylbenzonic acid(HL), and characterized by means of elemental analyses, infrared(IR) spectrometer, powder X-ray diffraction(PXRD), thermogravimetric analyses(TGA) and single-crystal XRD. The results reveal that complex 1 possesses a linear chain structure, complexes 2 and 3 possess isostructural ladder-like chains, while complex 4 possesses a 2D layer with 4-connected sql topology. Furthermore, the luminescence properties and UV-Vis spectra of complexes 2 and 3 were investigated.  相似文献   

10.
Three new gallium complexes formulated as [Ga(PDA)2][Ga(H2O)(PDA)(phen)]·4H2O(1), [Ga(PDA)2]· (H2IN)·2H2O(2) and [Ga(OH)(PDA)(H2O)]2(3)(H2PDA=pyridine-2,6-dicarboxylic acid; phen=1,10-phenanthroline; HIN=isonicotinic acid) have been synthesized under hydrothermal conditions. In the mixed-ligand system of complex 1, PDA2? and phen are connected to the central Ga3+ cation as tri- and bi-dentate ligands, respectively. In complex 2, each Ga3+ cation is six-coordinated by two PDA2? anions octahedrally. Complex 3 shows a binuclear structure, with the bond distance of Ga1-Ga2 being 0.30061(3) nm. The 3D supramolecular structures of the three complexes are constructed via hydrogen bonds and aromatic π-π packing interactions. All the three complexes exhibit intense blue emission at room temperature in the solid state, which are attributed to π*-π transition centered on the ligands.  相似文献   

11.
Ternary terbium complexes with p-aminobenzoic acid (HL), [TbL3(DMSO)(H2O)]2 (1), [TbL3(DMF)(H2O)]2 (2) and [TbL3(Bpy)(H2O)]2·2H2O (3) (DMSO=dimethyl sulfoxide, DMF=N, N- dimethylformamide, Bpy=2, 2′- bipyridyl) have been synthesized, and their crystal structures determined. The luminescence properties of these complexes, including both the emission quantum yield and the fluorescence lifetime, have been investigated. The effect of a second ligand on the crystal structure and luminescence property of the ternary terbium p-aminobenzoic acid complexes, and the relationship between luminescence properties and crystal structure, including coordination mode of the L ligand and the characteristics of a second ligand, are discussed.  相似文献   

12.
Based on a new biscarboxyl-functionalized Schiff base ligand 1,2-cyclohexanediamino-N,N'-bis[3-methoxyl-5-(p-carboxyl-phenylazo)] salicylidene(H4L), four polymers,[(CH3)2NH2]2·[Mn3(L)2(H2O)4]·2DMF(CP1),[Fe2(L)(H2O)(DMF)](CP2),[(CH3)2NH2]·[Cu(HL)]·H2O(CP3) and[Ni2(L)(teta)]·2DMF·H2O(CP4), have been synthesized(teta=5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane). In CP1, both of the internal[N2O2] pocket and the external carboxylate groups of L4- anion are ligated by Mn2+ ions, and the structure displays a layer. In CP2, the Fe2+ cations are linked by L4- anions to form a binuclear double chain. CP3 displays a[Cu2(HL)2] dimer. In CP4, the Ni2+ ions are connected by L4- anions to form a chain. The structures are further linked by hydrogen bonds to form 2D or 3D supramolecular architectures, respectively. CP1 exhibits adsorption ability to three organic dyes.  相似文献   

13.
金属-有机框架物在荧光识别领域表现出良好的应用前景,为探究合成更为精确识别的物质,本文利用二羧酸配体(H_2PAIA=5-丙酰胺基间苯二甲酸)和硝酸铜通过溶剂调控合成了两例结构不同的铜基金属-有机框架物(MOFs){[Cu(PAIA)(H_2O)]·2H_2O}(1)和{[Cu_3(PAIA)_2(DMSO)(Pyridine)_(1.5)]}(DMSO:二甲基亚砜;Pyridine:吡啶)(2)。尽管由相同的金属离子和有机配体构筑而成,但显示出具有显著溶剂导向特征的不同框架结构:配合物1为三维NbO型拓扑结构,而配合物2为二维sql型拓扑结构。正是由于这些结构上的差异,导致两个配合物的荧光识别性能和疏水性能展现出显著的不同。配合物1能够同时识别Pb~(2+)和Ag~+离子,而配合物2只能识别Pb~(2+),对Ag~+没有明显的信号响应。配合物1的疏水角85.06°比配合物2的52.71°有显著的增加。  相似文献   

14.
Five transition metal coordination compounds, [Mn2(8-qoac)2(bdc)(H2O)4](1)(8-qoacH=quinoline-8-oxy- acetate acid, H2bdc=benzene-1,4-dicarboxylic acid), [Zn4(8-qoac)4(bdc)2]n(2), {[Cd2(8-qoac)2(Hip)2(H2O)2]· (H2O)4}n(3)(H2ip=benzene-1,3-dicarboxylic acid), [Pb3(8-qoac)2(bdc)1.5(H2O)Cl]n(4) and [Zn2(8-qoac)(8-ql)(bdc)]n (5)(8-Hql=8-hydroxyquinoline), were synthesized by hydrothermal syntheses of metal salts with benzenedicarboxy- lic acid and 8-qoacH. Compound 1 possesses a discrete dimer bridged by bdc2- ligand. Compound 2 presents a 2D layer network constructed from bdc2- linkers and 1D infinite ribbons, in which Zn(II) centers are bridged by 8-qoac- with a tetradentate binding mode. Compound 3 displays a 1D zigzag chain, with adjacent chains further connected via extensive O-H···O hydrogen bonds to generate a 3D supramolecular structure. Compound 4 shows a 3D framework containing trinuclear lead secondary building units and bdc2- linkers, in which a new coordination mode of 8-qoac- ligand is observed. In compound 5, Zn(II) ions are simultaneously bridged by 8-qoac-, 8-ql- and bdc2- ligands to form tetranuclear zinc units, which are further interlinked by bdc2- linkers to yield a 2D wave-like layer. Based on intraligand(IL)(π-π*) fluorescent emission, compounds 1―5 possess strong purple fluorescent emissions. In addition, the thermal stabilities of compounds 1―5 were studied.  相似文献   

15.
The enthalpies of dissolution in water of new ternary complexes of four late trivalent lanthanide ions Ln(Gly)4Im(ClO4)3·nH2O (Ln=Gd, Tb, Dy, Y; Gly: glycine; Im: imidazole and n=1 or 2) were measured by means of a Calvet microcalorimeter. Empirical formulae for the calculation of the enthalpies of dissolution (ΔdissH), relative apparent molar enthalpies (ΔdissH (app)), relative partial molar enthalpies (ΔdissH (partial)) and enthalpies of dilution (ΔdilH1,2) were obtained from the experimental data of the enthalpies of dissolution of these complexes. The plot of ΔdissHmΘ, ΔdissH (app) and ΔdissH (partial) versus the values of the ionic radius of the lanthanide element (r) showed a grouping effect of the lanthanide elements, indicating that the coordinated bond between the lanthanide ions and the ligands has some covalent character. The unknown value of the standard enthalpy of dissolution for the similar complex: Ho(Gly)4Im(ClO4)3·H2O was estimated according to the plot of ΔdissHmΘ versus r.  相似文献   

16.
The infrared spectra of isotopically dilute (matrix-isolated HDO molecules) isostructural compounds M(HCOO)2·2H2O (M=Mn,Fe,Co,Ni,Zn,Cu) are presented and discussed in the region of the OD stretching modes. According to the structural data the compounds under study are divided into two groups: in M(HCOO)2·2H2O (M=Mn,Ni,Zn) the H2O(1) molecules form stronger hydrogen bonds as compared to H2O(2); in M(HCOO)2·2H2O (M=Fe,Co,Cu) the H2O(2) molecules form stronger hydrogen bonds as compared to the H2O(1) molecules. The influence of the metal–water interactions (synergetic effect) and the unit-cell volumes (repulsion potential of the lattice) on the hydrogen bond strength within the isostructural series is discussed. The wavenumbers of the uncoupled OD stretching modes of the HDO molecules influenced by guest ions (Cu2+ ions matrix-isolated in M(HCOO)2·2H2O and M2+ ions matrix-isolated in Cu(HCOO)2·2H2O) are presented and commented. For example, the analysis of the spectra reveals that when Cu2+ ions are included in the structure of M(HCOO)2·2H2O the hydrogen bonds of the type M–OH2OCHO–Cu are considerably weaker as compared to those of the same type formed when M2+ ions are included in the structure of Cu(HCOO)2·2H2O if the cations remain unchanged.  相似文献   

17.
A series of new 2D-layered structural rare-earth coordination polymers with the general formal [Ln(C8H4O5)(H2O)5]·(H2O)·(C8H4O5)1/2 (Ln=Eu for (1); Gd for (2); Tb for (3); Dy for (4); and Er for (5)) have been yielded by hydrothermal synthesis. The coordination polymers crystallize in monoclinic space group C/2c with a=19.838(16), b=10.529(8), c=17.752(14) Å, β=107.503(14)° for (1), with a=19.823(7), b=10.552(4), c=17.762(6) Å, β=107.443(6)° for (2), with a=19.770(4), b=10.519(2), c=17.698(4) Å, β=107.52(3)° for (3), with a=19.632(2), b=10.492(2), c=17.617(3) Å, β=107.470(12)° for (4), with a=19.648(7), b=10.480(3), c=17.598(6) Å, β=107.502(6)° for (5), respectively. And the metal ions (Ln3+) are located in nine-member coordination environment. The carboxyl groups from 5-hydroxyisophthalate chelate the metal ions to form 1D helical cation chains. It is interesting that these helical cation chains are arranged to form 2D anion–cation layers by the uncoordinated ligands' anions as template. And the luminescence properties of the rare-earth ions are studied in the paper.  相似文献   

18.
There has been great interest in the study of the magnetic properties of molecular-based compounds[1,2]. In the present work, we employed N,N-dimethylformide (DMF) as a hybrid ligand to synthesize a new family of cyano-bridged complexes contain rare earth and Manganese:[Ln(DMF)4(H2O)2Mn(CN)6·H2O]n (abbreviated as LnMn, Ln=Sm, Eu, Gd, Tb, Dy, Er) and the crystal data of former three complexes has been obtained, which display a remarkable variety of magnetochemical behavior and a rich structural chemistry.  相似文献   

19.
The praseodymium and europium dichloroacetates were obtained in the form of monocrystals. Crystal structures of the Ln(HCl2CCOO)3·2H2O (Ln=Pr, Eu) compounds were determined by X-ray analysis. Both crystals proved to be isomorphous. They are monoclinic, space group P21/n with: a=9.747(6), b=13.857(7), and c=23.595(9) Å, β=95.03(4)°, U=3175(3) Å3, Z=8 for C6H7Cl6O8Pr and a=9.634(7), b=13.757(11), and c=23.524(14) Å, β=94.84(4)°, U=3107(4) Å3, Z=8 for C6H7Cl6O8Eu. There are two symmetry independent lanthanide cations, which adopt a nine-coordinate geometry with seven oxygen atoms from carboxylate groups and two oxygen atoms from water molecules. Absorption (Pr3+, Eu3+), emission and emission excitation (Eu3+) spectra of single crystals of Ln(HCl2CCOO)3·2H2O were recorded at room temperature and low temperatures down to 4.2 K. Spectral intensities of the investigated systems are parametrized in terms of the Judd–Ofelt theory and compared to those of lanthanide trichloroacetates and acetates crystals. The relationship between the hypersensitivity and covalency is discussed. The nephelauxetic ratio β and Sinha's parameter δ are calculated based on the absorption spectra. The variation of these parameters and their correlation with the nature of metal–ligand bond is discussed. The bond polarity and bond strength of coordination complex determine the activity and stereospecifity of the catalyst thus the study of these properties are very important because of the application of lanthanide carboxylates as precursors of catalysts. The spectroscopic results are correlated with those from the crystal structure studies, especially with Ln–O distances and the co-ordinating forms of the carboxylate ions. The vibronic coupling in the f–f transitions were analysed. In order to determine the vibronic coupling quantitatively, calculations of the R=IVIB./I0-phonon rates were performed from the low temperature absorption spectra. The correlation between the vibronic coupling and covalency is analysed.  相似文献   

20.
Two 3D multifunctional lanthanide metal-organic frameworks(MOFs), Pr(HTCPS)(H2O)·2DMF·C2H5OH· 5H2O(JUC-93) and Pr3(TCPS)2(NO3)(H2O)4(DMA)2·2DMA·C2H5OH·3H2O(JUC-94)[H4TCPS=tetrakis(4-carboxyphenyl)- silane, DMF=N,N'-dimethylformamide, DMA=N,N'-dimethylacetamide and JUC=Jilin University China] were synthesized by the self-assembly of a rigid silicon-centered tetrahedral carboxylate ligand H4TCPS and Pr(III) ions in different solvothermal reactions. X-Ray crystallography revealed that they exhibited a rare CaF2 topology framework, constructed from the 4-connected tetrahedral TCPS unit with the 8-connected dinuclear praseodymium cluster unit and trinuclear praseodymium cluster unit, respectively. In addition, the luminescent and magnetic properties of the two compounds were investigated.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号