共查询到20条相似文献,搜索用时 15 毫秒
1.
《Journal of Inorganic and Nuclear Chemistry》1978,40(8):1537-1541
The complexes formed in the reaction between some lanthanide perchlorates and N-(2-pyridyl)acetamide (aapH) have been prepared and characterized. The compounds have the formulae [Ln(aapH)4] (ClO4)3 (where Ln Pr, Nd, Eu, Gd, Ho, Yb and Lu) and are solid crystalline substances. The new compounds were characterized by means of chemical analyses, molar conductivities, vibrational spectra, thermograviemetry and electronic absorption and emission spectra. The vibrational spectra and molar conductances indicate that the perchlorate groups are ionic and that aapH acts as a bidentate ligand through the carbonyl oxygen and the ring nitrogen. The PMR of La(aapH)4 (ClO4)3 and [Lu(aapH)4]ClO4)3 reveals that the ligands are planar and corroborates the vibrational evidence that they coordinate in a bidentate manner. The oscillator strength (Pexp) of the hypersensitive transition of the Nd(III) complex has been studied and the nephelauxetic effect has been evalauted. The emission of the Eu(III) complex at 77° is very intense and a tentative assignment of its symmetry has been made. 相似文献
2.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1991,47(6):727-736
Salicylaldehyde(N-benzoyl)glycyl hydrazone (SalBzGH) has been synthesized and characterized. Metal complexes of the empirical formula [Ln(SalBzGH-2H)OH(H2O)2] where Ln = Y, Pr, Nd, Sm, Eu, Gd and Dy, have been synthesized and their structures studied by infrared, far-infrared, absorption, emission and NMR spectra. 1H and 13C NMR spectra indicate the presence of dynamic equilibrium between two isomers of SalBzGH over the 298–368 K temperature range and stabilization of a single isomer upon complexation with Ln(III). The hypersensitive band profile of the Nd(III) complex indicates a change in metal coordination number due to solvation, while an increase of temperature results in a decrease of εmax of the hypersensitive band. The emission spectrum of [Eu(SalBzGH-2H)OH(H2O)2] at 77 K indicates a low site symmetry. SalBzGH coordinates through imidolic oxygen, azomethine nitrogen and phenolate oxygen. 相似文献
3.
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
4.
Gilberto F. De Sá 《Polyhedron》1983,2(10):1057-1058
The synthesis of the mixed complexes of the europium ion with 2-pyridylcarbinol-N-oxide, and 2,2′-dipyridyl and 1,10-phenanthroline were prepared. The compounds, were characterized by means of chemical analyses, vibrational spectra, molar conductivities, and electronic spectra. The emission of the [EuL3, phen] complex at 10 K is very intense and an assignment of the point symmetry of the Eu(III) ion has been made. 相似文献
5.
《Journal of Coordination Chemistry》2012,65(5):741-753
The formation of ternary complexes between lanthanide ions [Nd(III) or Eu(III)], octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO), and bis-(2-ethylhexyl)phosphoric acid (HDEHP) was probed by liquid–liquid extraction and spectroscopic techniques. Equilibrium modeling of data for the extraction of Nd(III) or Eu(III) from lactic acid media into n-dodecane solutions of CMPO and HDEHP indicates the predominant extracted species are of the type [Ln(AHA)2(A)] and [Ln(CMPO)(AHA)2(A)], where Ln?=?Nd or Eu and A represents the DEHP? anion. FTIR (for both Eu and Nd) and visible spectrophotometry (in the case of Nd) indicate the formation of the [Ln(CMPO)(A)3] complexes when CMPO is added to n-dodecane solutions of the LnA3 compounds. Both techniques indicate a stronger propensity of CMPO to complex Nd(III) versus Eu(III). 相似文献
6.
《Journal of Coordination Chemistry》2012,65(17):2725-2734
Reactions of Ln(ClO4)3?·?6H2O (Ln=La(III), Eu(III), Nd(III)), 1,10-phenanthroline (phen) and phenoxyacetic acid (PA) or 2,4-dichlorophenoxyacetic acid (2,4-D) yield [La(PA)2 (phen)2]2(ClO4)2 (1), [Eu(2,4-D)2(phen)2]2(ClO4)2 (2) and [Nd(2,4-D)3(C2H5OH)] n (3). Compounds 1–3 are characterized by elemental analyses, IR, UV–Vis, ESI-MS spectra and TGA. 1 is also characterized by 1H and 13C NMR. Single crystal X-ray diffraction analyses reveal that 1 and 2 are binuclear, and 3 has a one-dimensional polymeric structure. The La(III), Eu(III) and Nd(III) are nine-coordinate with a distorted tricapped trigonal-prism geometry. 相似文献
7.
Complexes of lanthanoid trinitrates Ln(NO3)3 with 15-crown-5 ether 1 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd) and with 18-crown-6 ether 2 (Ln = La, Ce, Pr, Nd) having a 1:1 stoichiometry as well as 4:3 complexes with 2 (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd) have been synthesized and characterized. All the isolated complexes are solvent free. At 170–220° the 1:1 complexes of 2 are quantitatively transformed into 4:3 complexes. X-Ray powder diagrams of the neodymium complexes with 2 indicate that both the 1:1 and 4:3 complexes are genuine compounds. All the 1:1 complexes show a characteristic IR. absorption band at 875–880 cm?1 absent from both the spectra of the free ligands and of the 4:3 complexes. The spectroscopic properties (IR. and electronic spectra, fluorescence lifetimes) of the complexes and the low magnetic moments of the Ln(III) ions in the complexes with Ln = Ce-Eu are indicative of a strong interaction between the lanthanoid ions and the crown ethers 1 and 2 . 相似文献
8.
O. V. Konnik V. F. Shul’gin S. V. Abkhairova S. B. Meshkova E. B. Rusanov V. V. Minin 《Russian Journal of Coordination Chemistry》2014,40(1):28-33
Complexes of the general formula LnL3 · Phen (Ln = Nd, Sm, Eu, Gd, Tb, Dy, and Yb; HL = 4-formyl-3-methyl-1-phenylpyrazol-5-one, Phen = 1,10-phenanthroline) were obtained and examined by IR spectroscopy and thermogravimetry. The structure of the complex TbL3 · Phen was studied by X-ray diffraction. The coordination polyhedron of terbium is a distorted square antiprism made up of six O atoms of three 4-formylpyrazol-5-one anions and two N atoms of the 1,10-phenanthroline molecule. Polycrystalline samples of the complexes studied show emission in the spectral ranges characteristic of Ln(III). 相似文献
9.
Seven new μ‐oxamido copper(II)‐lanthanide(III) heterobimetalic complexes described by the formula Cu(obbz) Ln‐(Ph‐phen)2NO3(Ln = La, Nd, Eu, Gd, Tb, Ho, Er), where obbz denotes the oxamidobis(benzoato) and Ph‐phen represents 5‐phenyl‐1, 10‐phenanthroline, have been synthesized and characterized by the elemental analyses, spectroscopic (IR, UV, ESR) studies, magnetic moments (at room temperature) and molar conductivity measurement. The temperature dependence of the magnetic susceptibility of Cu(obbz)Gd(Ph‐phen)2NO3 complex has been measured over the range 4.2–300 K. The least‐squares fit of the experimental susceptibilities based on the spin Hamiltonian operator, ? = ?2 J?1·?2, yielded J= +1.28 cm?1, a weak ferromagnetic coupling, A plausible mechanism for a ferromagnetic coupling between Gd(III)‐Cu(II) is discussed in terms of spin‐polarization. 相似文献
10.
《Journal of Coordination Chemistry》2012,65(18):1537-1547
Solid complexes of lanthanide picrates with 1,1′-(3,6,9-trioxaundecanedionyl)diphenothiazine (L), [Ln(pic)3L] (Ln = La, Nd, Eu, Gd, Er, Y), have been prepared and characterized by elemental analysis, IR and 1H NMR spectra. The molecular structure of [Er(pic)3L]·1/2C2H5OH shows that five oxygens of L form a ring-like coordination structure. Er(III) is 9-coordinated by L together with the other two unidentate and one bidentate picrate anions, revealing a tri-capped distorted trigonal prism geometry. Solvent extraction of Ln(III) with L has been carried out in a water–nitrobenzene system by use of the multitracer method. The relationship between the complex structure and extractabilities of the ligand is discussed. 相似文献
11.
《Polyhedron》2002,21(18):1837-1844
This work reports the synthesis, characterization and spectroscopic studies of Eu(III)-perchlorate complexes with amide ligands derived from N-[x-methylpyridyl]acetamide where x=3, 4 and 6. The Eu(ClO4)33(x-mpa) complexes were characterized by elemental analyses, molar conductance, TG analyses and vibrational spectroscopy. Raman and infrared data show that the perchlorate ion, (ClO4 −), is bonded to Eu(III) as a monodentate ligand and that in these three complexes water molecules are not coordinated to the rare earth ion. The profiles of the emission spectra of the complexes with 3- and 4-mpa ligands are very similar but they differ from the complex containing 6-mpa ligand. This spectroscopic behavior can be rationalized in terms of the Ωλ (λ=2 and 4) and R02 experimental intensity parameters. The values of Ω2 (∼6.5×10−20 cm2) in these complexes are smaller than in Eu(III)-TTA compounds (Ω2∼35.0×10−20 cm2), indicating that in the former case the rare earth ion is in a chemical environment less polarizable. Lifetime and emission quantum efficiency measurements for the emitting level 5D0 were carried out and the results are discussed. 相似文献
12.
《Journal of Coordination Chemistry》2012,65(12):1862-1874
The synthesis and characterization of lanthanide(III) complexes with the Schiff-base hydrazone, o-hydroxyacetophenone-7-chloro-4-quinoline, (HL) are reported. The complexes were characterized by different physicochemical methods: mass spectrometry, 1H NMR, 13C NMR, and IR, UV-visible, molar conductance and magnetic studies. They have the stoichiometry [Ln(L)2(NO3)]·nH2O where Ln = La(III), Pr(III), Nd(II), Sm(III), Eu(III) and n = 1–3. The spectra of the complexes were interpreted by comparison with the spectrum of the free ligand. The Schiff-base ligand and its metal complexes were tested against one stain Gram +ve bacteria (Staphylococcus aureus), Gram ?ve bacteria (Escherichia coli), and Fungi (Candida albicans). The tested compounds exhibited high antimicrobial activities 相似文献
13.
《Journal of Coordination Chemistry》2012,65(3):424-430
Four 2-D coordination polymers Ln2(phen)2(C5H6O4)3 [Ln?=?Pr(1), Eu(2), Er(3), Yb(4), phen?=?1,10-phenanthroline] were obtained via hydrothermal reactions and determined by X-ray diffraction analysis. The crystal structure data reveal that these complexes are isostructural. In the asymmetric unit, the two Ln(III) ions are nine-coordinate and have similar coordination environments. The Ln(III) ions are built into 2-D layers by three different coordination modes of glutarate. The resulting 2-D layer forms 3-D supramolecular architecture by two types of π···π stacking interactions. All the complexes were characterized by IR spectra and thermogravimetric analysis, and the emission spectrum shows that Eu2(phen)2(C5H6O4)3 possesses strong luminescence. 相似文献
14.
Seven new μ-isophthalato dinuclear lanthanide(III) complexes, namely [Ln2(IPHTA)(Me2-phen)4-(ClO4)2](ClO4)2 (Ln=La, Nd, Sm, Eu, Gd, Ho, Er), where Me2-phen denotes 2,9-dimethyl-1,10-phenanthroline (Me2-phen), IPHTA represents isophthalate dianion, have been synthesized and characterized by elemental analyses, molar conductance measurements, IR, ESR and electronic spectra. The variable-temperature magnetic susceptibilities of [ Gd2 (IPHTA) (Me2-phen)4 ( ClO4 )2 ] ((ClO4 )2 complex were measured in the temperature range of 4–300 K and the observed data were successfully simulated by the equation based on the spin Hamiltonian operator, H = -2JS1. J2. giving the exchange parameter J = -0.19 cm?1. This result is commensurate with a weak antiferromagnetic spin-exchange interaction between Gd(III)-Gd(III) im within the complex. 相似文献
15.
Optical spectroscopy of lanthanide ions in ZnO-TeO2 glasses 总被引:2,自引:0,他引:2
Rolli R Wachtler K Wachtler M Bettinelli M Speghini A Ajò D 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2001,57(10):2009-2017
Zinc tellurite glasses of compositions 19ZnO-80TeO2-1Ln2O3 with Ln = Eu, Er, Nd and Tm were prepared by melt quenching. The absorption spectra were measured and from the experimental oscillator strengths of the f-->f transitions the Judd-Ofelt parameters ohm(lambda) were obtained. The values of the ohm(lambda) parameters are in the range usually observed for oxide glasses. For Nd3+ and Er3+, luminescence spectra in the near infrared were measured and the stimulated emission cross sections sigma(p) were evaluated for some laser transitions. The high values of sigma(p), especially for Nd3+, make them possible candidates for optical applications. Fluorescence line narrowing (FLN) spectra of the Eu3+ doped glass were measured at 20 K, and the energies of the Stark components of the 7F1 and 7F2 states were obtained. A crystal field analysis was carried out assuming a C2v site symmetry. The behaviour of the crystal field ratios B22/B20 and B44/B40 agrees reasonably well with the values calculated using the geometric model proposed by Brecher and Riseberg. The crystal field strength at the Eu3+ sites appears to be very low compared to other oxide glasses. 相似文献
16.
《Journal of Coordination Chemistry》2012,65(5):863-874
New heteronuclear Ln(III)–Bi(III) complexes (Ln?=?Nd, Eu, Tb, Yb, Lu) with ethylenediamine-N,N,N′,N′-tetraacetic (H4edta), trans-1,2-cyclohexane-diamine-N,N,N′,N′-tetraacetic (H4cdta), diethylenetriamine-N,N,N′,N″,N″-pentaacetic (H5dtpa), and triethylenetetraamine-N,N,N′,N″,N″′,N″′-hexaacetic (H6ttha) acids have been synthesized with a different synthetic approach. Bi(III) is a sensitizer of the 4f-luminescence in visible and near IR region. Emission spectra of Eu(III)–Bi(III) complexes were studied and the asymmetry of Eu(III) coordination environment was estimated, in good agreement with molecular models. The complexes synthesized by self-assembly are characterized by higher values of the 4f-luminescence quantum yield than other Ln(III)–Bi(III) complexes. 相似文献
17.
《Journal of Coordination Chemistry》2012,65(3):499-504
Abstract Complexes with composition Ln2(β-diketonate)6 (dmm) (Ln = Eu, Tb; dmm = 2,6-dimethyl-morpholine; β-diketonate = 4,4,4-trifluoro-l-(2-thienyl)-l,3-butanodionate (tta); 4,4,4-tri-fluoro-1-phenyl-1,3-butanodionate (tfpb) and l,l,l-trifluoro-l,4-pentanedionate (tfa)) have been synthesized. The adducts were characterized by microanalyses, IR spectra and emission spectra at room temperature and at 77K. The spectra of europium complexes indicate the oligomeric at least dimeric, nature of the compounds, since the bands are broad. The number of peaks in all cases was interpreted as C3V symmetry around the central ion. 相似文献
18.
《Journal of Coordination Chemistry》2012,65(2):95-103
Abstract A complex of europium perchlorate with methylene bis(diphenylphosphine oxide) (HMPPO), [Eu(HMPPO)4](ClO4)3·2H2O has been synthesized and characterized by X-ray crystallography, infrared spectroscopy and thermal analysis. The X-ray structure of the complex shows Eu(III) is coordinated by eight oxygen atoms from four HMPPO ligands, forming a distorted square antiprism coordination geometry. The complex crystallizes in space group P-1 with cell parameters a = 15.807(3), b = 17.868(4), c = 20.656(4) Å, α = 86.85(3)°, β = 82.33(3)°, γ = 66.75(3)°. The final Rl and Rw are 0.0803 and 0.1994, respectively, for 9540 observed reflections [I > 2[sgrave](I)]. Its luminescent properties have also been studied. 相似文献
19.
《Journal of Coordination Chemistry》2012,65(10):855-864
Four cyano-bridged 3d–4f hetero-bimetallic Ln(III)–Fe(III) assemblies, {[Ln(DMF)4(H2O)3(µ-CN)Fe(CN)5]· H2O} n (Ln?=?Ce (1), Nd (2), Sm (3) and Gd (4); DMF?=?N,N-dimethylformamide), have been synthesized. X-ray crystallographic analysis of both 3 and 4 reveals three-dimensional network structures resulting from hydrogen bonds in the crystals. With respect to the coordination number on Sm(III) atoms, 3 is different from previously reported structures. Structural comparison indicates that the differences in magnetic properties between 3 and 4 do not derive from structural factors. Mössbauer spectra at both 298 and 10?K reveal that the characteristic quadrupole splitting for low-spin Fe(III) ions (S?=?1/2) remains unchanged, indicating that the spin state of Fe(III) ions in 1–4 is not affected by temperature. The magnetic anisotropy derived from the ground states of Ln(III) ions with odd 4f n electrons (n?=?1, 3, 5 and 7), 2F5/2,4I9/2, 6H5/2 and 8S7/2 for Ce(III), Nd(III), Sm(III) and Gd(III), respectively, dominates the exchange interaction in the Ln(III)–NC–Fe(III) systems. 相似文献
20.
Synthesis and characterization of Pr(III), Nd(III) and Er(III) complexes with 2,6-pyridinedimethanol
The reactions of Ln(NO3)3?6H2O (Ln=Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H2pydm) in a 1:2 M ratio were investigated, and complexes with the formula [Ln(H2pydm)2(NO3)2](NO3) (Ln=Pr or Nd) (1 and 2) and [Er(H2pydm)3](NO3)3 (3) were isolated. The compounds contain 10-coordinate Pr(III) and Nd(III) ions that crystallize in the triclinic space group P-1 while the 9-coordinate Er(III) complex crystallizes in the monoclinic system (P21/n). A new lanthanide complex, [Pr(H2pydm)3](Cl)3?DMF (4), has been synthesized by reaction of PrCl3?6H2O and H2pydm. The nine-coordinate Pr(III) is bound to three H2pydm ligands. X-ray crystal structures of 1–4 reveal that the ligand coordinates tridentate via the pyridyl nitrogen and the two hydroxyl oxygens. The electronic absorption spectra of 1–4 show 4f–4f transitions. 相似文献