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1.
Lighter and heavier lanthanide(III) ions react with dihydrazinium salts of ethylenediaminetetraacetic acid (H4edta) in aqueous solution to yield hydrazinium lanthanide ethylenediaminetetraacetate hydrate, N2H5[Ln(edta)(H2O)3]·(H2O)5 where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb and Dy. The numbers of water molecules present inside the coordination sphere have been confirmed by X-ray single crystal studies. The presence of five water molecules as lattice water is clearly shown by the mass loss from the TG analyses. Dehydration of a known amount (1 g) of each sample were carried out at constant temperature (100–110°C) for about 5 min further confirms the number of non-coordinated water molecules. The complexes after the removal of lattice water undergo multi-step decomposition to give respective metal oxide as the final product. The DTA shows endotherms for dehydration and exotherms for the decomposition of the anhydrous complexes. The formation of the metal oxides was confirmed by X-ray powder diffraction studies.  相似文献   

2.
The new hydrazinium lanthanide metal complexes of 2-pyrazinecarboxylic acid (HpyzCOO) of the formulae (N2H5)2[Ln(pyzCOO)5] · 2H2O (1), where Ln = La or Ce and (N2H5)3[Ln(pyzCOO)4(H2O)] · 2NO3 (2), where Ln = Pr, Nd, Sm or Dy have been synthesized and characterized by physico-chemical methods. The IR absorption bands of N–N stretching at 960 cm−1 unambiguously prove the existence of N2H5 + ions. The bonding parameters β, b1/2, % δ and η, have been calculated from the electronic spectroscopic (hypersensitive) bands of Pr(III) and Nd(III) complexes. All the complexes undergo endothermic followed by exothermic decomposition to leave the respective metal oxides as the end products. However, the DTA of the complexes 2 demonstrate rather sharp peak than the complexes 1, owing to overwhelming exothermicity, which may be due to the loss of both hydrazine and nitrate moieties in the same step. The X-ray powder diffraction studies reveal the existence of isomorphism among the member complexes.  相似文献   

3.
Some new and bis-hydrazine lanthanide glyoxylates Ln[OOC-CHO]3(N2H4)2 where Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb or Dy have been prepared and the compositions of the complexes have been determined by chemical analysis and elemental analysis. The magnetic moment and electronic spectra suggest except Ln3+ which is diamagnetic and all the other complexes are paramagnetic. Infrared spectral data indicate the bidentate coordination of carboxylates group is coordinate to lanthanide ion in a monodentate fashion. However, as a whole, glyoxylate ion acts as a bidentate ligand. The curves of all the complexes show multi-step degradation and the final products are found to be the respective metal oxides. The final residues were identified by their metal analysis, infrared spectra and the X-ray powder diffraction patterns. X-ray powder patterns of the complexes are almost super-imposable as expected which is in favour of isomorphism among the series.  相似文献   

4.
Two types of isostructural complexes of lanthanide chlorides with diglyme have been synthesized. These are mononuclear molecular complexes [LnCl3(diglyme)(THF)] (Ln = Eu ( 1 ), Gd ( 2 ), Dy ( 3 ), Er ( 4 ), Yb ( 5 ); diglyme = diethylen glycol dimethyl ether) and binuclear molecular complexes [LnCl3(diglyme)]2 (Ln = Dy ( 3d ), Er ( 4d ), Yb ( 5d )). Complex 1 was obtained by the reaction of [EuCl3(DME)2] with diglyme in THF. The complexes 2 – 5 and 3d – 5d resulted from reactions of LnCl3·6H2O, (CH3)3SiCl and diglyme in THF. The mononuclear complexes 2 – 5 crystallized directly from the solutions where the reactions of lanthanide compounds with diglyme took place. Recrystallizations of the powder products of the same reactions from dichloromethane resulted in the binuclear complexes 3d – 5d . Reactions of lanthanide bromide hydrates, (CH3)3SiBr and diglyme in THF achieved mononuclear molecular complexes [LnBr3(diglyme)(L)] (Ln = Gd, L = H2O ( 6 ); Ln = Ho, L = THF ( 7 )). Crystals of 6 and 7 were grown by recrystallization from dichloromethane. The lanthanide atoms (Ln = Eu–Yb) are seven‐coordinated in a distorted pentagonal bipyramidal fashion in all reported complexes, 1 – 7 and 3d – 5d . Four oxygen atoms and three halide ions are coordinated to lanthanide atoms in 1 – 7 , [LnX3(diglyme)(L)]. Four chloride ions, two bridging and two nonbridging, and three oxygen atoms are coordinated to lanthanide atoms in 3d – 5d , [LnCl3(diglyme)]2.  相似文献   

5.
Treatment of Ln(NO3)3?nH2O with 1 or 2 equiv 2,2′‐bipyrimidine (BPM) in dry THF readily afforded the monometallic complexes [Ln(NO3)3(bpm)2] (Ln=Eu, Gd, Dy, Tm) or [Ln(NO3)3(bpm)2]?THF (Ln=Eu, Tb, Er, Yb) after recrystallization from MeOH or THF, respectively. Reactions with nitrate salts of the larger lanthanide ions (Ln=Ce, Nd, Sm) yielded one of two distinct monometallic complexes, depending on the recrystallization solvent: [Ln(NO3)3(bpm)2]?THF (Ln=Nd, Sm) from THF, or [Ln(NO3)3(bpm)(MeOH)2]?MeOH (Ln=Ce, Nd, Sm) from MeOH. Treatment of UO2(NO3)2?6H2O with 1 equiv BPM in THF afforded the monoadduct [UO2(NO3)2(bpm)] after recrystallization from MeOH. The complexes were characterized by their crystal structure. Solid‐state luminescence measurements on these monometallic complexes showed that BPM is an efficient sensitizer of the luminescence of both the lanthanide and the uranyl ions emitting visible light, as well as of the YbIII ion emitting in the near‐IR. For Tb, Dy, Eu, and Yb complexes, energy transfer was quite efficient, resulting in quantum yields of 80.0, 5.1, 70.0, and 0.8 %, respectively. All these complexes in the solid state were stable in air.  相似文献   

6.
We report the synthesis of Ln3+ nitrate [Ln(Tpm)(NO3)3] ⋅ MeCN (Ln=Yb ( 1Yb ), Eu ( 1Eu )) and chloride [Yb(Tpm)Cl3] ⋅ 2MeCN ( 2Yb ), [Eu(Tpm)Cl2(μ-Cl)]2 ( 2Eu ) complexes coordinated by neutral tripodal tris(3,5-dimethylpyrazolyl)methane (Tpm). The crystal structures of 1Ln and 2Ln were established by single crystal X-ray diffraction, while for 1Yb high resolution experiment was performed. Nitrate complexes 1Ln are isomorphous and both adopt mononuclear structure. Chloride 2Yb is monomeric, while Eu3+ analogue 2Eu adopts a binuclear structure due to two μ2-bridging chloride ligands. The typical lanthanide luminescence was observed for europium complexes ( 1Eu and 2Eu ) as well as for terbium and dysprosium analogues ([Ln(Tpm)(NO3)3] ⋅ MeCN, Ln=Tb ( 1Tb ), Dy ( 1Dy ); [Ln(Tpm)Cl3] ⋅ 2MeCN, Ln=Tb ( 2Tb ), Dy ( 2Dy )).  相似文献   

7.
A series of neutral mononuclear lanthanide complexes [Ln(HL)2(NO3)3] (Ln = La, Ce, Nd, Eu, Gd, Dy, Ho) with rigid bidentate ligand, HL (4′-(1H-imidazol-1-yl)biphenyl-4-carboxylic acid) were synthesized under solvothermal conditions. The coordination compounds have been characterized by infrared spectroscopy, thermogravimetry, powder X-ray diffraction and elemental analysis. According to X-ray diffraction, all the complexes are a series of isostructural compounds crystallized in the P2/n monoclinic space group. Additionally, solid-state luminescence measurements of all complexes show that [Eu(HL)2(NO3)3] complex displays the characteristic emission peaks of Eu(III) ion at 593, 597, 615, and 651 nm.  相似文献   

8.

Abstract  

By using 1,4-benzene-dicarboxylic acid and 1,2,4,5-benzenetetracarboxylic acid as mixed-linkers, three novel 3D lanthanide coordination polymers, [Ln(BDC)0.5(BTEC)0.5(H2O)] (Ln = Eu (1) and Gd (2)) and [Tb(BDC)0.5(BTEC)0.5(H2O)] (3) (H2BDC = 1,4-benzene-dicarboxylic acid, H4BTEC = 1,2,4,5-benzenetetracarboxylic acid) were synthesized via hydrothermal reaction. The X-ray single crystal analyses reveal that the three coordination polymers present two types of different crystal cell parameters and hereby exhibited two kinds of different metal–organic frameworks, although they have the similar chemical formula [Ln(BDC)0.5(BTEC)0.5(H2O)]. Of these complexes, complexes 1 and 2 are isomorphous, crystallizing in monoclinic, space group P21/n. While 3 is a 3D eight-coordinated terbium complex with triclinic crystal system and P-1 space group. The occurrence of the different structures of these complexes under the similar preparation method may be related to the lanthanide contraction effect. Additional, the thermogravimetric analyses and photoluminescent properties for complexes 1 and 3 were discussed in detail.  相似文献   

9.
New complexes of lanthanide nitrates with 4N-(2′-hydroxy benzylidene)-aminoantipyrine (HBAAP) having the general formula [Ln(HBAAP)2(NO3)3] (where Ln = La, Pr, Nd, Sm, Gd, Tb, Dy, Ho and Y) have been prepared and characterized. Conductance studies indicate non-electrolytic behaviour for these complexes. Their infrared spectra show that both the ligand and the nitrate group are bound to the metal ion in a bidentate fashion. Electronic spectra indicate weak covalent character in the metal-ligand bond. Thermogravimetric studies indicate that these complexes are stable up to ~200°C and undergo complete decomposition in the range 200–550° resulting in the formation of the stable lanthanide oxides.  相似文献   

10.
The multi-step dehydration and decomposition of trivalent lanthanum and lanthanide heptanediate polyhydrates were investigated by means of thermal analysis completed with infrared study. Further more, X-ray diffraction data for investigated heptanediate complexes of general stoichiometry Ln2(C7H10O4)3.nH2O (wheren=16 in the case of La, Ce, Pr, Nd and Sm pimelates,n=8 for Eu, Gd, Tb, Dy, Er and Tm pimelates,n=12 for Ho, Yb and Lu pimelates) were also reported.
Zusammenfassung Mittels TG, DTG, DTA wurde in Verbindung mit IR-Methoden der mehrstufige Dehydratations- und der Zersetzungsvorgang der Polyhydrate der PimelinsÄuresalze von dreiwertigem Lanthan und dreiwertigen Lanthanoiden untersucht. Röntgendiffraktionsdaten der untersuchten Heptandiat-Komplexe mit der allgemeinen Formel Ln2(C7H10O4)3 nH2O (mitn=16 für Ln=La, Ce, Pr, Nd und Sm,n=8 für Ln=Eu, Gd, Tb, Dy, Er und Tm sowien=12 für Ln=Ho, Yb und Lu) werden ebenfalls gegeben.
  相似文献   

11.
Double sulfates of rare earths and tetramethylammonium with empirical formula (CH3)4NLn(SO4)2 · 3H2O (Ln=Ce, Pr, Nd, Eu, Gd, Tb and Dy) were synthesized and studied by the methods of TG, DTG and DTA in the temperature range from 20 to 500°C, and by X-ray powder diffraction and chemical analysis. Two isostructural groups were obtained: one from Ce to Eu and another from Gd to Dy. It was found that rare earth sulfates are obtained as final products at 500°C. For comparison, TG, DTG and DTA curves of the thermal decomposition of tetramethylammonium sulfate are given.
Zusammenfassung Doppelsulfate von Seltenerden und Tetramethylammonium der empirischen Formel (CH3)4NLn(SO4)2 · 3H2O mit Ln=Ce, Pr, Nd, Eu, Gd, Tb und Dy wurden synthetisiert und im Temperaturbereich 20–500°C mittels TG, DTG und DTA, weiterhin mittels Röntgenpulverdiffraktion und chemischer Analyse untersucht. Es wurden zwei isostrukturelle Gruppen erhalten, die eine von Ce bis Eu, die andere von Gd bis Dy. Man fand, daß man bei 500°C als Endprodukt die Seltenerdensulfate erhält. Zum Vergleich wurden die TG-, DTG- und DTA-Kurven der thermischen Zersetzung von Tetramethylammoniumsulfat gegeben.


Financial support by the Research Council of Slovenia is gratefully acknowledged.  相似文献   

12.
A series of lanthanide–transition metal (Ln–M) complexes, namely, {[Ln2Cu(pydc)4(H2O)3]·H2O} n (Ln = Tb, Eu, Sm or Gd) (H2pydc = 2,5-pyridinedicarboxylic acid) have been synthesized hydrothermally by self-assembly of the lanthanide ions, copper(II) ions and 2,5-pyridinedicarboxylic acid. All the complexes were characterized by physicochemical and spectroscopic methods; in addition, structural analyses revealed that all four complexes crystallized in monoclinic space group P21 /c. The molecular structure contains both Cu and Ln atoms, with pydc ligands bridging the four coordinate Cu(II) centers and eight coordinate lanthanide centers to form a 3-D net structure. Hence, copper is oxidized from Cu(I) to Cu(II) during the preparation. In addition, the thermogravimetric analysis of 1 is discussed. Contrary to expectations, compounds 13 show no photoluminescent properties. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

13.
Twelve oxamide-bridged Ln(III)–Cu(II) heteropentanuclear complexes Ln[Cu(PMoxd)]4(ClO4)3 · 5H2O (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and PMoxd = the N,N′-Bi(α-pyridylmethyl)-oxamide dianion) and 12 oxamide-bridged Ln(III)–Cu(II) heteropentanuclear complexes with the formula of Ln[Cu(PEoxd)]4(ClO4)3 · 5H2O (PEoxd = the N,N′-Bi(α-pyridylethyl)-oxamide dianion) were synthesized and characterized. The magnetic properties of Gd[Cu(PMoxd)]4(ClO4)3 · 5H2O (7) and Gd[Cu(PEoxd)]4(ClO4)3 · 2H2O (19) show that there are ferromagnetic interactions between Gd(III) and Cu(II) in the complexes with J Cu–Gd = 1.38 cm?1 and J Cu–Gd = 1.00 cm?1, respectively. Fluorescent quenching phenomena for Eu[Cu(PMoxd)]4(ClO4)3 · 5H2O (6) and Tb[Cu(PMoxd)]4(ClO4)3 · 5H2O (8) were also observed.  相似文献   

14.
The synthesis of a new series of cationic monoporphyrinates with “light” lanthanide ions is reported. The meso-tetrakis(4-pyridyl)porphyrin, (tpyp)H2, was used as the tetrapyrrole ligand, and the metallation reaction with the lanthanide ions in acetyl-acetonato form, leading to Ln(tpyp)acac, where Ln = Sm, Eu, Gd and Tb, was carried out. The cationic monoporphyrinates, Ln(tmepyp)acac, were synthesized via the corresponding Ln(tpyp)acac. These complexes are freely soluble in aqueous and non-aqueous solutions, like MeOH, H2O or N,N-dimethylformamide. Their spectroscopic properties in water and DMF solutions are reported. All the complexes were characterized on the basis of their UV-vis, IR and ESR data. No ESR spectra were obtained for cationic porphyrins in DMF for Sm, Eu and Tb, while the spectra of Gd(tmepyp)acac in DMF exhibits smaller ΔHpp (103.1 G) among the spectra of GdIII complexes. The unexpected broad signal of Eu(t-mepyp)acac, ΔHpp = 126.9 G, in H2O is discussed in terms of the formal oxidation state +2 for the central ion.  相似文献   

15.
The reaction of 1,8-diamino-3,6-diazaoctane and diethyl malonate in dry methanol yielded a 13-membered macrocycle. Complexes of the type [Ln(tatd)Cl2 (H2O)3]Cl [LnIII=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy; tatd=1, 5, 8, 11-tetra-azacyclotridecane-2,4-dione] have been synthesized by template condensation. The complex [La(tatd)Cl2 (H2O)3]Cl in methanol was reacted with lanthanide chlorides to yield the trinuclear complexes of type [2{La(tatd)Cl2(H2O)3}LnCl3]Cl2 [LnIII=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy]. The chemical compositions of mono and trinuclear complexes have been established on the basis of analytical, molar conductance, electrospray (ES) and fast atom bombardment (FAB) mass data. In mononuclear complexes the Ln3+ ion is encapsulated by four ring nitrogens and in trimetallic complexes the exo-carbonyl oxygens of two mononuclear units coordinate to the Ln3+ ions resulting in a polyhedron around the lanthanide ions. Thus the macrocycle is bonded in a tetradentate fashion in the former complexes and hexadentate in the latter. The coordination number nine around the encapsulated Ln3+ and seven around the exo-oxygen bonded Ln3+ ions are established. The symmetry of the ligand field around the metal ions is indicated from the emission spectra.  相似文献   

16.
A mesogenic Schiff-base, N,N′-di-(4-decyloxysalicylidene)-1′,3′-diaminobenzene, H2ddsdbz (abbreviated as H2L), that exhibits a nematic mesophase was synthesized and its structure was studied by elemental analysis, mass spectrometry, NMR, and IR spectral techniques. The Schiff-base, H2L, upon condensation with hydrated lanthanide(III) nitrates yields LnIII complexes, [Ln2(LH2)3(NO3)4](NO3)2, where Ln?=?La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Ho. Analyses of the IR and NMR spectral data imply bidentate Schiff-base through two phenolate oxygen atoms in its zwitterionic form to LnIII, rendering the overall geometry of the complexes as a seven-coordinate polyhedron – possibly distorted mono-capped octahedron. Polarizing optical microscope and differential scanning calorimetry studies reveal that despite H2L being mesogenic, none of the LnIII complexes synthesized under this study exhibits mesomorphism.  相似文献   

17.
Three new solid lanthanide(III) complexes, [Ln(1-AMUH)3] · (NO3)3 (1-AMUH = 1-amidino-O-methylurea; Ln = Eu(III), Gd(III), or Tb(III)) were synthesised and characterised by elemental analysis, infrared spectra, magnetic moment measurement, and electron paramagnetic resonance (EPR) spectra for Gd(III) complex. The formation of lanthanide(III) complexes is confirmed by the spectroscopic studies. The photophysical properties of Gd(III), Eu(III), and Tb(III) complexes in solid state were investigated. The Tb(III) complex exhibits the strongest green emission at 543 nm and the Eu(III) complex shows a red emission at 615 nm while the Gd(III) complex shows a weak emission band at 303 nm. Under excitation with UV light, these complexes exhibited an emission characteristic of central metal ions. The powder EPR spectrum of the Gd(III) complex at 300 K exhibits a single broad band with g = 2.025. The bi-exponential nature of the decay lifetime curve is observed in the Eu(III) and Tb(III) complexes. The results reveal them to have potential as luminescent materials.  相似文献   

18.
An exchange reaction of the sodium salt of 3-methyl-1-phenyl-4-formylpyrazol-5-one (HL) with chlorides or nitrates of lanthanides (Ln = La, Nd, Sm, Eu, Gd, Tb, Dy, and Yb) was used to synthesize coordination compounds of composition LnL3·nSolv (Solv = H2O or EtOH). According to powder X-ray diffraction data, these compounds constitute two series: one comprises lanthanum and neodymium complexes, and the other, samarium, europium, gadolinium, terbium, dysprosium, and ytterbium complexes. For the complexes of the first series, the structure was solved in a single-crystal diffraction experiment carried out on [La2(μ-L)3(L)3(H2O)3]·2MeOH. The lanthanum atoms in the complex are at a distance of 4.222(2) — from each other, and they are structurally nonequivalent and linked by three 5-hydroxy-4-formylpyrazole anions. Solid-phase samples of the coordination compounds under study feature weak luminescence in the spectral regions intrinsic to lanthanide cations.  相似文献   

19.
A novel mixed-ligand complexes with empirical formulae: Ln(4-bpy)1.5(CCl3COO)3·nH2O (where Ln(III) = Pr, Sm, Eu, Gd, Tb; n = 1 for Pr, Sm, Eu and n = 3 for Gd, Tb; 4-bpy = 4,4′-bipyridine) were prepared and characterized by chemical, elemental analysis and IR spectroscopy. Conductivity studies (in methanol, dimethylformamide and dimethylsulfoxide) were also described. All complexes are crystalline. The way of metal–ligand coordination was discussed. The thermal properties of complexes in the solid state were studied under non-isothermal conditions in air atmosphere. During heating the complexes decompose via intermediate products to the oxides: Pr6O11, Ln2O3 (for Sm, Eu, Gd) and Tb4O7. TG-MS system was used to analyze principal volatile thermal decomposition and fragmentation products evolved during pyrolysis of Pr(III) and Sm(III) compounds in air.  相似文献   

20.
Three series of copper–lanthanide/lanthanide coordination polymers (CPs) LnIIICuIICuI(bct)3(H2O)2 [Ln=La ( 1 ), Ce ( 2 ), Pr ( 3 ), Nd ( 4 ), Sm ( 5 ), Eu ( 6 ), Gd ( 7 ), Tb ( 8 ), Dy ( 9 ), Er ( 10 ), Yb ( 11 ), and Lu ( 12 ), H2bct=2,5‐bis(carboxymethylmercapto)‐1,3,4‐thiadiazole acid], LnIIICuI(bct)2 [Ln=Ce ( 2 a ), Pr ( 3 a ), Nd ( 4 a ), Sm ( 5 a ), Eu ( 6 a ), Gd ( 7 a ), Tb ( 8 a ), Dy ( 9 a ), Er ( 10 a ), Yb ( 11 a ), and Lu ( 12 a )], and LnIII2(bct)3(H2O)5 [Ln=La ( 1 b ), Ce ( 2 b ), Pr ( 3 b ), Nd ( 4 b ), Sm ( 5 b ), Eu ( 6 b ), Gd ( 7 b ), Tb ( 8 b ), and Dy ( 9 b )] have been successfully constructed under hydrothermal conditions by modulating the reaction time. Structural characterization has revealed that CPs 1 – 12 possess a unique one‐dimensional (1D) strip‐shaped structure containing two types of double‐helical chains and a double‐helical channel. CPs 2 a – 12 a show a three‐dimensional (3D) framework formed by CuI linking two types of homochiral layers with double‐helical channels. CPs 1 b – 9 b exhibit a 3D framework with single‐helical channels. CPs 6 b and 8 b display visible red and green luminescence of the EuIII and TbIII ions, respectively, sensitized by the bct ligand, and microsecond‐level lifetimes. CP 8 b shows a rare magnetic transition between short‐range ferromagnetic ordering at 110 K and long‐range ferromagnetic ordering below 10 K. CPs 9 a and 9 b display field‐induced single‐chain magnet (SCM) and/or single‐molecule magnet (SMM) behaviors, with Ueff values of 51.7 and 36.5 K, respectively.  相似文献   

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