II) And Europium Research Articles

Cd(II) and Cd(II)–Eu(III) Complexes with Pentafluorobenzoic Acid Anions and N-Donor Ligands: Synthesis and Structures

The reactions of cadmium(II) and europium(III) pentafluorobenzoates ([Cd(Pfbz) $$\left( {{{{\text{H}}}_{{\text{2}}}}{\text{O}}} \right)_{{\text{4}}}^{ + }$$ }n ∙ n(Pfbz)–] (I) and [Eu2(Pfbz)6(H2O)8] ∙ 2H2O (II), respectively; Pfbz is pentafluorobenzoic acid anion) with the N-donor ligands (pyridine (Py), 2-phenylpyridine (Phpy), and 3-ethynylpyridine (Etypy)) afford a series of new Cd–Ln complexes with Pfbz– anions and Py or its substituted analogues: [Cd2Eu2(Pfbz)10(Py)4] (III), [Cd2Eu2(Pfbz)10(Phpy)2(MeCN)2] · 5MeCN (IV), and [CdEu2(Pfbz)8(Etypy)(H2O)2]n ∙ 3nMeCN ∙ n(Etypy) (VI). Similar reactions of compounds I and II with 2,4-lutidine (Lut), isoquinoline (Iquin), 2,2'-biquinoline (Biquin), and 7,8-benzoquinoline (Bquin) give the following cadmium complexes as the major products of crystallization from the reaction solutions: [Cd(Pfbz)2(Lut)]n (V), [Cd(H2O)(Pfbz)2(Iquin)2]n (VII), [Cd(Рfbz)2(Biquin)] (VIII), and $$[{\text{Cd}}{{({\text{Pfbz}})}_{{\text{3}}}}]_{n}^{-}$$ ∙ n(HBquin)+ (IX), respectively. The X-ray diffraction data (CIF files CCDC nos. 1987805 (I), 1987808 (III), 1987829 (IV), 1987817 (V), 1987822 (VI), 1987823 (VII), 1987824 (VIII), and 1987826 (IX)) are examples of the formation of new unusual coordination polymers.

Bimetallic 3d—4f-molecules [MEu(ButCOO)5(1,10-phen)] (M = Zn2+, Co2+, phen is phenanthroline): synthesis, structure, luminescent and magnetic properties

New heterometallic complexes [MEu(Piv)5(1,10-phen)]•MeCN (M = Zn2+ (1), Co2+ (2), Piv– = ButCOO–, 1,10-phen is 1,10-phenanthroline) were obtained. Luminescence spectra of compound 1 reveal a metal-centered Eu3+ luminescence, the luminescence lifetime is about 1 ms. Using TGA and DSC methods, it was shown that [ZnEu(Piv)5(1,10-phen)] is a stable binuclear molecule undergoing a structural transformation in the 210—230 °C temperature range, which leads to a partial transition of the sample into the glass state. Complex 2 does not exhibit luminescence due to the presence of high-spin cobalt(II) ions. The magnetic behavior of 2 according to calculations based on the molecular field model is determined by spin-orbit interactions of cobalt(II) and europium(III) ions.

Luminescent properties of europium ions in CaAl2SiO6

The CaAl2SiO6 aluminosilicate nanocrystals doped with europium(II) and europium(III) ions have been synthesized using the sol–gel method. To obtain Eu2+ ions, samples were annealed in the reducing atmosphere.The XRD diffractograms, excitation and emission spectra, as well as the decay time profiles were measured and analyzed. Nanocrystals doped with Eu3+ ions possess sharp emission peaks, which are assigned to the 5D0 → 7FJ transitions, where the most intensive is 5D0 → 7F2 luminescence. The decay curve of the europium(III) emission is single exponential. The asymmetry factor around the Eu3+ ions was calculated from the emission spectrum.CaAl2SiO6 nanocrystallites containing Eu2+ ions possess the broad emission band in the visible range with maximum at 530 nm. Emission decay time of the 0.2% sample is equal 1.7 μs at 300 K and has multi exponential character.

Syntheses and structures of heterometallic complexes M-Co(II) (M = Li(I), Mg(II), and Eu(III)) with anions of 2-naphthoic acid. An influence of the heterometal on the structure of the complex

A series of polynuclear heterometallic cobalt(II) 2-naphthoate complexes with lithium(I), magnesium(II), and europium(III) is synthesized: [(2,2′-Bipy)2Li2Co2(Naph)6], [(2,4-Lut)2Co2Mg(Naph)6], and [(2,2′-Bipy)2(EtOH)2Co2Eu2(Naph)10] (Naph is 2-naphthoic acid anion, 2,2′-Bipy is 2,2′-bipyridine, and 2,4-Lut is 2,4-lutidine). The single crystals of the synthesized compounds are characterized by X-ray diffraction analysis (CIF files CCDC 1401987 (I), 1401988 (II), 1401989 (III), and 1401990 (IV)). The compositions and structures of the molecular heterometallic complexes based on cobalt(II) cations and anions of 2-naphthoic acid are determined by the radius and coordination number of the introduced heterometal: the isomorphic substitution of one of the cobalt(II) ions is observed for the magnesium(II) complex, and tetranuclear complexes are formed in the case of lithium(I) and europium(III).

A Europium-151 Mössbauer Spectral Study of Eu14MnP11, Eu14MnAs11, and Eu14MnSb11

The europium-151 Mossbauer spectra of the Eu(14)MnP(11), Eu(14)MnAs(11), and Eu(14)MnSb(11) Zintl compounds, measured between 4.2 and 100 K, reveal europium(II) for all four crystallographically inequivalent europium sites in Eu(14)MnAs(11) and Eu(14)MnSb(11) and europium(II) and europium(III) for the three 32g and the 16f europium sites in Eu(14)MnP(11), respectively. Below the ordering temperatures of 52, 74, and 92 K, only very small hyperfine fields of 2-4 T are observed at the europium sites as a result of the polarization by the manganese magnetic moments. At 4.2 K, the europium(II) magnetic moments are ordered, and hyperfine fields of 24.4, 24.8, and 19.3 T are observed in Eu(14)MnP(11), Eu(14)MnAs(11), and Eu(14)MnSb(11), respectively, fields that are typical for magnetically ordered europium(II) ions. At 4.2 K the 16f europium(III) sites in Eu(14)MnP(11) experience a transferred hyperfine field of 33 T from the neighboring ordered europium(II) moments. Between its Curie temperature and 4.2 K, the europium-151 Mossbauer spectra of Eu(14)MnSb(11) reveal that the europium(II) moments order below ca. 13 K, i.e., below the second magnetic transition observed in magnetic measurements. Between their Curie temperatures and 4.2 K, the europium-151 Mossbauer spectra of Eu(14)MnP(11) and Eu(14)MnAs(11) are complex and have been analyzed with two models, models that give equivalently good fits. However, the second model in which the spectra are fit with a three-dimensional relaxation of the europium(II) and europium(III) hyperfine fields is preferred for its physical meaning and its reduced number of fitted parameters.

Solvation of uranyl(II) and europium(III) cations and their chloro complexes in a room-temperature ionic liquid. A theoretical study of the effect of solvent "humidity".

We report a molecular dynamics study of the solvation of the UO2(2+) and Eu3+ cations and their chloro complexes in the [BMI][PF6][H2O] "humid" room-temperature ionic liquid (IL) composed of 1-butyl-3-methylimidazolium+ and PF6- ions and H2O in a 1:1:1 ratio. When compared to the results obtained in dry [BMI][PF6], the present results reveal the importance of water. The "naked" cations form UO2(H2O)5(2+) and Eu(H2O)9(3+) complexes, embedded in a shell of 7 and 8 PF6- anions, respectively. All studied UO2Cln(2-n) and EuCln(3-n) chloro complexes remain stable during the dynamics and coordinate additional H2O molecules in their first shell. UO2Cl4(2-) and EuCl6(3-) are surrounded by an "unsaturated" water shell, followed by a shell of BMI+ cations. According to an energy component analysis, the UO2Cl4(2-) and EuCl6(3-) species, intrinsically unstable toward dissociation, are more stable than their less halogenated analogues in the IL solution, due to the solvation forces. The different chloro species also interact better with the humid than with the dry IL, which hints at the importance of solvent humidity to improve their solubility. Humidity markedly modifies the local ion environment, with major consequences as far as their spectroscopic properties are concerned. We finally compare the aqueous interface of [BMI][PF6] and [OMI][PF6] ionic liquids, demonstrating the importance of imidazolium substituents (N-butyl versus N-octyl) to the nature of the interface and miscibility with water.

Redox Potentials of Samarium and Europium in Molten Lithium Chloride

Abstract The samarium (III)/(II) and europium (III)/(II) redox potentials in molten lithium chloride were measured using the direct potentiometric method in the temperature range from 923 to 1094 K. Glassy carbon was used as the indifferent working electrode, and the standard chlorine electrode as a reference. The total concentration of rare-earth chlorides dissolved in molten lithium chloride did not exceed 4.5 mol%.

Synthesis and Crystal Structures of Mono-Helical Complexes of Zinc(II) and Europium(III) with 1,2-Bis{[3-(2-pyridyl)pyrazol-1-yl]ethoxy}ethane

A new multidentate ligand L, 1,2-bis{[3-(2-pyridyl)pyrazol-1-yl]ethoxy}ethane, has been synthesized by linking two 3-(pyridin-2-yl)pyrazoles with a 1,2-bis(ethoxy)ethyl spacer. Coordination of L with zinc(II) and europium(III) centres has led to mononuclear complexes of [Zn(L)](ClO4)2 (1) and [Eu(L)Cl2](ClO4) (2). X-ray crystal structures of both complexes have shown that L adopted a helical coordination geometry around both metal centres. The spectroscopic properties of both complexes have also been determined. In 1, photoluminescence was dominated by ligand centred 1(π-π*) fluorescence. In 2, ligand-to-metal energy transfer leading to 5D0 7Fn luminescence at the europium(III) centre was observed.

Enhanced performance of polythiophene derivative based light emitting diodes by addition of europium and ruthenium complexes

Fabrication of polymer light emitting diodes (PLEDs) from a urethane containing processable polythiophene derivative, poly[2-(3-thienyl) ethanol n-butoxy carbonylmethyl urethane], (PURET) and its composites with luminescent Ruthenium (II) and Europium (III) complexes is discussed. Enhanced electroluminescence (EL) performance was observed, when 1% by weight of europium (III) or ruthenium (II) complexes were added to the PURET polymer. Multi-layered devices with polyaniline as a hole injecting layer and tris-8-hydroxyquinoline-aluminum as an electron injecting layer have also been fabricated. PLEDs from PURET polymer have a threshold voltage of 3.6 V and emit an orange-red light with a brightness of about 500 cd/m 2 under forward bias of 9 V, upon the addition of 1% of europium (III) thenoyl trifluoroacetonate complex to the polymer.

Selective detection of nitrogen and oxygen containing volatile organic compounds: use of metal-modified polysiloxanes as sensor coatings

Polysiloxanes containing 3-heptafluorobutanoyl (Hfb) camphorates of metal ions, e.g. zinc(II), nickel(II) and europium(III), have been used successfully as sensitive layers for thickness shear mode resonators (TSMRs). These sensing layers provide pronounced selectivity in detecting volatile organic compounds (VOCs) in the gas phase and in particular analytes containing heteroatoms, such as O and N. The selectivity results from co-ordinative binding between the electronically unsaturated metal complexes and the heteroatom-containing analytes. This leads to detection limits in the ng l −1 (ppb)-range especially for nitrogen-containing compounds under conditions of slow but perfect reversibility.

Electron transfer between Eu and Tb in complex fluorides

Europium (II) and europium (III) have been observed in MMgF4:xEu, yTb (M = Ca, Sr, Ba) phosphors using their typical photoluminescence spectra when are synthesized in Ar or an Ar/H2 stream. The valence state of Eu is influenced by terbium. It is notable that the intensities of the electron spin resonance peaks corresponding to Eu2+ change in a regular way when terbium ions are incorporated which can be explained by an electron transfer mechanism.

Elecutron Transfer and its Equilibrium between Eu and Tb in SrMgF<sub>4</sub> System

Emission of europium(II) and europium(III) have been observed in SrMgF4 xEu, yTb phosphors winch are synthesized in Ar flow. The valence state of En is influenced by terbium, It is noted that the intensities of the ESR peaks corresponding to Eu2+ are increased when terbium ion is codopech this can be explained by electron transfer mechanism which is Eu3++Tb3+-->Eu2++Tb4+. And its equilibrium constant is calculated.

A continuous spectrophotometric assay for the activation of plant NAD kinase by calmodulin, calcium(II), and europium(III) ions

A continuous spectrophotometric assay has been developed to quantify the calmodulin, calcium(II) ion, and europium(III) ion dependence of the activation of NAD kinase from pea seedlings. Experimental enzyme activation data are compared with the theoretical curves for the binding of calcium(II) ions to the individual calcium binding sites of calmodulin. These results indicate that the binding of three calcium(II) ions is necessary for activation of plant NAD kinase. Further studies demonstrate that europium(III) ions can replace calcium(II) ions in calmodulin with retention of its ability to activate NAD kinase.

Evaluation of electrochemical charge-transfer rates by using (real) laplace space analysis: Single potential-step chronoamperometry of hexacyanoferrate(III)/(II) and Europium(III)/(II) couples

The one-electron hexacyanoferrate(III)/(II) and europium(III)/(II) redox couples were evaluated by using single-pulse chronoamperometry at a planar glassy carbon electrode (and also a mercury-pool electrode for europium) to test Wijnen's method for calculating heterogeneous electron-transfer rate constants by using (real-axis) Laplace space analysis. The k 0 values obtained for the former couple in potassium or lithium chloride supporting electrolytes agreed well with published constants obtained by diverse real-time techniques. Transfer coefficients (α 0) obtained from (ϖ in k a /ϖη) η=0 for LiCl electrolyte were 0.4–0.5, rather than 0.22 previously reported. The cathodic rate values calculated for europium(III) reduciton (in NaClO 4/HClO 4) on both glassy carbon and mercury agreed very well with each other and with published values obtained by d.c. polarography and faradaic impedance measurements. Owing to several factors, including its ability to utilize virtually any set of recorded i( t) data points, Wijnen's Laplace technique offers an attractive alternative to conventional single-pulse analysis in real-time.

Temperature dependence of excited-state electron-transfer reactions. Quenching of RuL32+ emission by copper(II) and europium(III) in aqueous solution

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTemperature dependence of excited-state electron-transfer reactions. Quenching of RuL32+ emission by copper(II) and europium(III) in aqueous solutionJ. E. Baggott and M. J. PillingCite this: J. Phys. Chem. 1980, 84, 23, 3012–3019Publication Date (Print):November 1, 1980Publication History Published online1 May 2002Published inissue 1 November 1980https://doi.org/10.1021/j100460a008RIGHTS & PERMISSIONSArticle Views698Altmetric-Citations18LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts

Solvent extraction of cobalt(II), zinc(II) and europium(III) with 4-thiobenzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (SBMPP)

Solvent extraction of65zinc,60cobalt and152+154europium from aqueous buffers into benzene containing 4-thiobenzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one (SBMPP) has been investigated in detail (μ=0.1, T=26±1°C). The species extracted and the values of log Kex, where Kex refers to the extraction equilibrium, are ZnL2 (−2.68) CoL2(−3.08) and EuL3(−7.08), where L is the anion of the ligand. The sulfur analog appears to be more effective than the parent ligand 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-one in the extraction of zinc(II) and cobalt(II), whereas the reverse is true with europium(III).

ChemInform Abstract: POLAROGRAPHIC STUDIES OF BIS(2,2′,2′′‐TERPYRIDINE) COMPLEXES OF MANGANESE(II), COBALT(II), NICKEL(II) AND EUROPIUM(III) IN ACETONITRILE

Chemischer InformationsdienstVolume 6, Issue 20 Organoelement Compounds ChemInform Abstract: POLAROGRAPHIC STUDIES OF BIS(2,2′,2′′-TERPYRIDINE) COMPLEXES OF MANGANESE(II), COBALT(II), NICKEL(II) AND EUROPIUM(III) IN ACETONITRILE MAKOTO AIHARA, MAKOTO AIHARASearch for more papers by this authorHIROFUMI KISHITA, HIROFUMI KISHITASearch for more papers by this authorSEIZO MISUMI, SEIZO MISUMISearch for more papers by this author MAKOTO AIHARA, MAKOTO AIHARASearch for more papers by this authorHIROFUMI KISHITA, HIROFUMI KISHITASearch for more papers by this authorSEIZO MISUMI, SEIZO MISUMISearch for more papers by this author First published: May 20, 1975 https://doi.org/10.1002/chin.197520356AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume6, Issue20May 20, 1975 RelatedInformation

Polarographic Studies of Bis(2,2′,2″-terpyridine) Complexes of Manganese(II), Cobalt(II), Nickel(II) and Europium(III) in Acetonitrile

Abstract The reduction mechanism of bis 2,2′,2″-terpyridine complexes of manganese(II), cobalt(II), nickel(II) and europium (III) were investigated in acetonitrile by means of DC and AC polarograph and Kalousek polarograph at DME and cyclic voltammetry at an HDME. It was found that univalent metal complex anions, such as [M-(terpy)2]− (M=manganese and nickel), were formed at the electrode surface in acetonitrile. For the europium(III) complex, the standard rate constant of the second reduction step was estimated.

Preparation, characterisation, and europium-151 Mössbauer spectra of some carbides, nitrides, nitride-carbides, cyanides, and thiocyanates of europium

The reaction of europium metal with HCN and (CN)2 at elevated temperatures has been shown to yield Eu2C3, EuC2, and compounds of the type EuNxCy. X-Ray parameters for these phases are reported and they are shown by 151Eu Mossbauer spectroscopy to be band systems. EuN is shown to be ionic and to contain Eu3+ ions. The reactions in liquid NH3 of europium with HCN, C2H2, and NH4SCN have been shown to produce europium(II) and europium(III) cyanide, europium(III) acetylide, and europium(III) thiocyanate respectively. The width of the 151Eu Mossbauer resonance is discussed in relation to possible bonding situations and the relationship between chemical isomer shift and bond ionicity is considered.

Comparative liquid-liquid extraction behaviour of europium (II) and europium (III)

The liquid-liquid extraction behaviour of Eu(II) into solutions of acidic phosphoric and phosphonic esters has been investigated both on a macro-scale and tracer-scale. The distribution ratio of Eu(II) was investigated as a function of extractant concentration in the organic phase and HCl concentration in the aqueous phase using β-active 13, 16 year 152, 154Eu. Advantage was taken of the large separation factors Pm(III)/Eu(II), Sm(III)/Eu(II), and Gd(III)/Eu(II) in effecting the mutual separation of 147Pm and 152, 154Eu, the high purification of 147Pm with respect to 152, 154Eu, and the enrichment, concentration and recovery in high yield of europium from a rare earth oxide containing 0·1 per cent Eu.