cas 7790-86-5, CERAMICS-AEium(III) chloride

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Oxa-adamantyl cannabinoids
As a continuation of earlier work on classical cannabinoids bearing bulky side chains we report here the design, synthesis, and biological evaluation of 3′-functionalized oxa-adamantyl cannabinoids as a novel class of cannabinergic ligands. Key synthetic steps involve nucleophilic addition/transannular cyclization of aryllithium to epoxyketone in the presence of cerium chloride and stereoselective construction of the tricyclic cannabinoid nucleus. The synthesis of the oxa-adamantyl cannabinoids is convenient, and amenable to scale up allowing the preparation of these analogs in sufficient quantities for detailed in vitro evaluation. The novel oxa-adamantyl cannabinoids reported here were found to be high affinity ligands for the CB1 and CB2 cannabinoid receptors. In the cyclase assay these compounds were found to behave as potent and efficacious CB1 receptor agonists. Isothiocyanate analog AM10504 is capable of irreversibly labeling both the CB1 and CB2 receptors.
Ho, Thanh C.,Tius, Marcus A.,Nikas, Spyros P.,Tran, Ngan K.,Tong, Fei,Zhou, Han,Zvonok, Nikolai,Makriyannis, Alexandros
supporting information

(2021/03/14)

The morphology evolution, tunable down-conversion luminescence, and energy transfer of [CaY]F2crystals doped with Li+/Ce3+/Tb3+
Octahedral [CaY]F2 crystals with an average particle size of 1 μm were synthesized via a mild one-step hydrothermal route without employing any surfactants. Various morphologies, including cubes, truncated cubes, truncated octahedrons, and spheres, were achieved via manipulating the amount of EDTA used, and a possible growth mechanism was proposed based on the surface energies of different crystal planes and the influence of the surfactant. XRD, SEM, EDS, TEM, HRTEM, and PL analysis were used to characterize the products. The effects of the morphologies and Li+ doping concentrations on the luminescence intensities of the [CaY]F2:Ce3+/Tb3+ phosphors were explored, and the strongest luminescence intensity is obtained when the sample is cubic with (100) crystal faces and the doping concentration of Li+ is 0.25 mol%. Additionally, multicolor emission (blue → aquamarine blue → green) was obtained from [CaY]F2:Ce3+/Tb3+ phosphors via adjusting the doping concentration of Tb3+, which resulted from the Ce3+ → Tb3+ energy transfer behavior; the energy transfer here happened through a dipole-dipole mechanism. This work may result in the as-synthesized phosphors having great application potential in many optoelectronic device fields, such as in displays and multicolor lighting.
Hu, Shanshan,Jiang, Li,Mao, Yini,Wang, Zhiyi,Yang, Jun,Ye, Rui
p. 15433 - 15442
(2020/11/18)

Thermodynamic stability of RECl3·xH2O (RE = Ce, Pr) determined by dynamic transpiration technique
In the present study, decomposition mechanism of CeCl3·xH2O(s) and PrCl3·xH2O(s) was investigated using thermogravimetry, differential thermal analysis and evolved gas analysis techniques. Intermediate products formed in the dehydration of RE (Ce, Pr) Cl3·xH2O(s) were characterized by X-ray diffraction analyses. Thermodynamic stability of the RECl3·xH2O(s) and their intermediate products has been determined from the vapor pressure of water measured over the compounds employing dynamic transpiration technique.
Sahoo,Mishra,Kumar, Raj,Kain, Vivekanand
p. 1183 - 1193
(2019/07/17)

Highly-selective recognition of latent fingermarks by La-sensitized Ce nanocomposites: Via electrostatic binding
Herein, a series of binuclear (Ce,La) nanocomposite fluorescent powders was elaborately designed for highly-selective recognition of latent fingermarks by the powder dusting method, which were proved to interact with fingermark residues via electrostatic binding without any damage to touch-DNA.
Peng, Di,Huang, Mengjun,Xiao, Yaruo,Zhang, Yuyan,Lei, Li,Zhu, Jiang
supporting information
p. 10579 - 10582
(2019/09/12)

Two Series of New Volatile Rare-Earth Metal Tris(guanidinates) and Tris(amidinates)
Two series of new volatile, homoleptic lanthanide(III) tris(guanidinate) and tris(amidinate) complexes were synthesized and fully characterized. Treatment of anhydrous rare-earth metal(III) chlorides, LnCl3, with three equiv. of the aziridine-derived lithium guanidinate Li[c-C2H4NC(NiPr)2] (3) afforded the new homoleptic tris(guanidinate) complexes [c-C2H4NC(NiPr)2]3Ln (4) (Ln = Sc, Pr, Nd, Sm, Eu, Ho, Tm) in good yields (68–80 %). In a similar manner, the homoleptic tris(amidinate) complexes [iPrC(NiPr)2]3Ln (6) Ln = Sc, Ce, Pr, Nd, Tb, Dy, Er, Yb) were prepared from LnCl3 and the all-isopropyl-substituted lithium amidinate Li[iPrC(NiPr)2] (5) in a molar ratio of 1:3. Variable-temperature 1H NMR studies of the paramagnetic derivatives 4Pr–4Tm revealed Curie-type behavior. 1H NMR spectroscopic data of complexes 6 indicated severe steric crowding due to the presence of nine isopropyl groups in these molecules. The molecular and crystal structures of eight title compounds (4Sc, 4Pr, 4Nd, 4Sm, 4Eu, 4Ho, 4Tm, and 6Er) were determined through single-crystal X-ray diffraction studies. All complexes 4 exhibit similar molecular structures, comprising distorted octahedral molecular structures with small bite angles. Sublimation temperatures of 4 at 0.05 mbar were determined to be in the range between 151 °C (4Eu) and 194 °C (4Tm), whereas the complexes 6 sublime in the temperature range between 140 °C (6Sc) and 180 °C (6Ce), so that the use of these precursors in future ALD or CVD studies appears feasible.
Tutacz, Peter,Harmgarth, Nicole,Z?rner, Florian,Liebing, Phil,Hilfert, Liane,Engelhardt, Felix,Busse, Sabine,Edelmann, Frank T.
p. 1653 - 1659
(2018/10/31)

PROCESS FOR THE PREPARATION OF SUBSTITUTED PHENOXYPHENYL ALCOHOLS
The present invention relates to a process for the preparation of the compounds of formula (II) using a lanthanoid salt.
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(2019/01/08)

Refractive indices and molar refractivities of molten rare-earth trichlorides and their mixtures with alkali chlorides
New experimental data on the refractive indices and molar refractivities of molten cerium, neodymium, samarium, and gadolinium trichlorides and CeCl3-ACl, SmCl3-ACl, Gd3Cl-ACl (A = Na, 0.5Na-0.5K, K, and Cs) mixtures depending on the temperature and composition are reported. It is shown that the relative deviations of the molar refractivity of mixtures from their magnitudes inherent to the hypothetic ideal solutions increase as the radii of alkali metal cations rises. The difference in variation of the Ln3+-ions electron polarizability with the atomic number or ionic radius is revealed for cerium and yttrium subgroups of the lanthanide row.
Kochedykov, Victor A.,Khokhlov, Vladimir A.
p. 44 - 51
(2017/11/10)

Lanthanide-doped Sr2ScF7 nanocrystals: controllable hydrothermal synthesis, the growth mechanism and tunable up/down conversion luminescence properties
Sr2ScF7:Ln3+ (Ln = Ce, Tb, Eu, Sm, Dy, Er, Tm, Ho and Yb) nanocrystals were firstly synthesized via a one-step hydrothermal route without employing any surfactants. The shape and size of the Sr2ScF7 nanocrystals could be readily tuned from nanorods with 120 nm length and 50 nm width to nanoparticles with a uniform diameter of 15 nm by doping 30% Ln3+ with a larger ionic radius. Furthermore, the influence of pH values, F? sources and different surfactants on the sizes and morphologies (including nanorods, quadrangular microplates, cubes and polyhedrons) of the as-prepared products was systematically investigated and the possible formation mechanism for the products has been proposed. The XRD, SEM, EDS, PL analysis and decay lifetimes were used to characterize the products. For DC photoluminescence, the Sr2ScF7:Ln3+ nanocrystals show the characteristic f-f transitions with emission colors of bluish violet (Ce3+, Tm3+), green (Tb3+, Er3+, Ho3+), blue (Dy3+) and orange (Eu3+, Sm3+) respectively. Under single wavelength 980 nm excitation, the blue UC emissions of Sr2ScF7:Yb3+,Tm3+ nanocrystals at 474 nm due to the 1G4 → 3H6 transition of Tm3+, the green UC emissions of Sr2ScF7:Er3+ nanocrystals at 522/544 nm assigned to the 2H11/2 → 4I15/2/4S3/2 → 4I15/2 transitions and the red UC emissions of Sr2ScF7:Yb3+,Er3+ at 660 nm from 4F9/2 → 4I15/2 transition of Er3+ were observed. Based on the generation of red, green, and blue emissions, the Sr2ScF7:Yb3+,Er3+,Tm3+ nanocrystals could produce multicolor, particularly in the white region (0.320, 0.330) by controlling the doping concentration of Tm3+ in the Sr2ScF7:Yb3+,Er3+,Tm3+ nanocrystals. Controlling the doping concentration of Tm3+ is an effective way of modulating the luminescence properties of Sr2ScF7:Ln3+ by controlling its size and morphology. The as-synthesized phosphors might be potentially applied in the fields of color displays, light, photonics and biological imaging.
Zhao, Bei,Shen, Dingyi,Yang, Jun,Hu, Shanshan,Zhou, Xianju,Tang, Jianfeng
p. 3264 - 3275
(2017/04/06)

Refractive indices and molar refractivities of molten rare-earth trichlorides and their mixtures with alkali chlorides
New experimental data on the refractive indices and molar refractivities of molten cerium, neodymium, samarium, and gadolinium trichlorides and CeCl3-ACl, SmCl3-ACl, Gd3Cl-ACl (A = Na, 0.5Na-0.5K, K, and Cs) mixtures depending on the temperature and composition are reported. It is shown that the relative deviations of the molar refractivity of mixtures from their magnitudes inherent to the hypothetic ideal solutions increase as the radii of alkali metal cations rises. The difference in variation of the Ln3+-ions electron polarizability with the atomic number or ionic radius is revealed for cerium and yttrium subgroups of the lanthanide row.
Kochedykov, Victor A.,Khokhlov, Vladimir A.
p. 44 - 51
(2017/12/02)

Luminescent coordination polymers for the VIS and NIR range constituting LnCl3 and 1,2-bis(4-pyridyl)ethane
A series of 14 lanthanide containing coordination polymers LnCl3 with 1,2-bis(4-pyridyl)ethane (bpe) was synthesized from either thiazole or pyridine. Depending on the ligand content, a structural diversity from 3D-frameworks 3∞[LnCl3(bpe)2]·thz, Ln = Ce-Lu, to 1D-strands 1∞[La2Cl6(bpe)2(thz)6] and 1∞[LnCl3(bpe)(py)2]·(bpe/py), Ln = Gd, Er, was obtained and characterized by X-ray single crystal diffraction, powder diffraction, differential thermal analysis and thermogravimetry (DTA/TG), IR-spectroscopy and photoluminescence spectroscopy. The compounds exhibit a variety of luminescence properties and different phenomena. This includes ligand centred fluorescence, metal-centred 5d-4f/4f-4f emission in the visible and the NIR range, antenna effects via Dexter and F?rster energy transfer mechanisms, excitation dependent emission with a correlating shift of the chromaticity coordinates and inner filter effects by combined re-absorption/emission.
Dannenbauer,Matthes,Müller-Buschbaum
p. 6529 - 6540
(2016/05/09)

Stereoelectronic factors in bridgehead C-H bond insertion: Studies toward the total synthesis of maoecrystal v
A strategy for the total synthesis of maoecrystal V is presented. The key interior vicinal quaternary carbon centers will be formed via sequential bridgehead C-H bond insertion and enolate functionalization. Studies herein validate the C-H bond insertion as feasible in model studies, though there are significant effects on the selectivity for the bridgehead position from neighboring groups. Both inductive electron withdrawing elements and sterics play a role in deactivating that position, with the former having a greater effect. Forming the second quaternary carbon is possible via enolate acylation and alkylation. Lastly, an approach to synthesize the cyclohexenone ring of maoecrystal V is described.
Jansone-Popova, Santa,May, Jeremy A.
p. 3734 - 3747
(2016/06/06)

Visible light photoredox and Polonovski-Potier cyclizations for the synthesis of (±)-5-epi-cermizine C and (±)-epimyrtine
Quinolizidine alkaloids epi-cermizine C and epimyrtine were synthesized from a common intermediate in 5–6 steps from commercially available materials. The key step involved an allylsilane cyclization with an iminium ion formed by oxidation of a tertiary amine. Oxidative annulation was promoted either catalytically by visible light photoredox catalysis or by stoichiometric Polonovski-Potier conditions. There was a modest difference in diastereoselectivity between the two methods, with photoredox providing the key quinolizidine intermediate in 4.7:1 dr versus 2:1 dr for the Polonovski route.
Benimana, Shami Eden,Cromwell, Nicholle E.,Meer, Humna N.,Marvin, Christopher C.
supporting information
p. 5062 - 5064
(2016/11/02)

Design of a Br?nsted acid with two different acidic sites: Synthesis and application of aryl phosphinic acid-phosphoric acid as a Br?nsted acid catalyst
A Br?nsted acid with two different acidic sites, aryl phosphinic acid-phosphoric acid, has been synthesized. Its catalytic performance was assessed in the hetero-Diels-Alder reaction of aldehyde hydrates with Danishefsky's diene, achieving high reaction efficiency.
Momiyama,Narumi,Terada
supporting information
p. 16976 - 16979
(2015/11/27)

Synthesis and Characterization of the Cerium(III) UV-Emitting 2D-Coordination Polymer 2 ∞[Ce2Cl6(4, 4′-bipyridine)4]·py
The 2D-coordination polymer 2 ∞[Ce2Cl6(bipy)4]·py (bipy = 4, 4′-bipyridine) shows a 5d-4f centered emission in the soft UV-B region. It was synthesized via the reaction of anhydrous CeCl3 and 4, 4′-bipyridine in pyridine under solvothermal conditions. The two-dimensional sheet structure consisting of 4, 4′-bipyridine coordinated Ce2Cl6 dimers closes the gap between the known lanthanum 3 ∞[La2Cl6(bipy)5]·4bipy framework and the 2D networks of the formula 2 ∞[Ln 2Cl6(bipy)3]·2bipy from praseodymium on. They differ in the number of coordinating bipy linkers, which decreases along La > Ce > Pr, with the remarkable observation that lanthanum, cerium, and praseodymium exhibit different network constitutions. The structure of 2 ∞[Ce2Cl6(bipy)4]·py exhibits a cem topology constituted of double strands, which are diagonally linked by 4, 4′-bipyridine forming trapezoid cavities in-between the strands. The cavities contain intercalated pyridine molecules.
Matthes, Philipp R.,Müller-Buschbaum, Klaus
p. 2847 - 2851
(2016/02/23)

Total synthesis of vinigrol
Carbocyclic cage fight: The substrate-controlled total synthesis of vinigrol features a strategic oxidative dearomatization/Diels-Alder cycloaddition reaction and a subsequent palladium-catalyzed cyclization cascade to construct the carbocyclic core. The C4, C9, and C12 stereocenters were installed using either reduction or oxidation reactions, and the diterpenoid core was unraveled by a ring fragmentation reaction. Copyright
Yang, Qingliang,Njardarson, Jon T.,Draghici, Cristian,Li, Fang
supporting information
p. 8648 - 8651
(2013/09/12)

Electrochemical and spectroscopic study of Ce(III) coordination in the 1-butyl-3-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ionic liquid containing chloride ion
Cyclic staircase voltammetry, controlled potential coulometry, and electronic absorption spectroscopy were used to probe the coordination and accessible oxidation states of Ce3+ dissolved in the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BuMePyroTf 2N) before and after the addition of chloride ion as BuMePyroCl. Controlled potential coulometry indicated that the oxidation of Ce metal in this ionic liquid produces only Ce3+. Spectroscopic examination of the resulting solutions indicated that Ce3+ was weakly solvated by Tf2N- ions as [Ce(Tf2N)x] (x-3)-, x ≥ 3. This species can be reduced at negative potentials, probably to a related Ce2+ species, but the latter is unstable and quickly disproportionates to Ce3+ and Ce0; the latter appears to react with the ionic liquid. The addition of Cl- to solutions of [Ce(Tf2N)x](x-3)- causes the precipitation of CeCl3(s), providing a convenient route to the nondestructive recovery of Ce3+ from the ionic liquid. However, as the Cl- concentration is further increased, the CeCl3(s) redissolves as the octahedral complex, [CeCl6]3-, and the voltammetric and spectroscopic signature for [Ce(Tf2N) x](x-3)- disappears. Absorption spectroscopy indicated that the bulk controlled potential oxidation of solutions containing [CeCl 6]3- produces [CeCl6]2-. Although stable on the time scale of voltammetry, this species slowly reacts with the ionic liquid and is converted back to [CeCl6]3-.
Chou, Li-Hsien,Cleland, Walter E.,Hussey, Charles L.
p. 11450 - 11457,8
(2020/10/15)

Study of the chemical chelates and anti-microbial effect of some metal ions in nanostructural form on the efficiency of antibiotic therapy norfloxacin drug
This paper has reviewed the chemical and biological impact resulting from the interaction between norfloxacin (norH) antibiotic drug and two lanthanide (lanthanum(III) and cerium(III)) metal ions, which prepared in normal and nano-features. La(III) and Ce(III) complexes were synthesized with chemical formulas [La(nor)3]·3H2O and [Ce(nor) 3]·2H2O. Lanthanum and cerium(III) ions coordinated toward norH with a hexadentate geometry. The norH acts as deprotonated bidentate ligand through the oxygen atom of carbonyl group and the oxygen atom of carboxylic group. Elemental analysis, FT-IR spectral, electrical conductivity, thermal analysis (TG/DTA), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) measurements have been used to characterize the mentioned isolated complexes. The Coats-Redfern and Horowitz-Metzger integral methods are used to estimate the kinetic parameters for the major successive steps detectable in the TG curve. The brightness side in this study is to take advantage for the preparation and characterization of single phases of La2O3 and CeO2 nanoparticles using urea as precursors via a solid-state decomposition procedure. The norH ligand in comparison with both cases (normal and nano-particles) of lanthanide complexes were screened against for antibacterial (Escherichia Coli, Staphylococcus Aureus, Bacillus subtilis and Pseudomonas aeruginosa) and antifungal (Aspergillus Flavus and Candida Albicans) activities. The highest antibacterial and antifungal activities data of the nano-particles complexes were observed with more potent than the free norH and normal lanthanide complexes.
Refat, Moamen S.,El-Hawary,Mohamed, Mahmoud A.
p. 45 - 54
(2012/04/23)

Analysis of the conformational behavior and stability of the SAP and TSAP isomers of lanthanide(III) NB-DOTA-type chelates
Controlling the water exchange kinetics of macrocyclic Gd3+ chelates, a key parameter in the design of improved magnetic resonance imaging (MRI) contrast media, may be facilitated by selecting the coordination geometry of the chelate. The water exchange kinetics of the mono- capped twisted square antiprism (TSAP) being much closer to optimal than those of the mono capped square antiprism (SAP) render the TSAP isomer more desirable for high relaxivity applications. Two systems have been developed that allow for selection of the TSAP coordination geometry in 1,4,7,10-tetraazacyclododecane-1,4,7,10- tetraacetic acid (DOTA)-type Gd3+ chelates, both based upon the macrocycle nitrobenzyl cyclen. In this paper we report investigations into the stability and formation of these chelates. Particular focus is given to the production of two regioisomeric chelates during the chelation reaction. These regioisomers are distinguished by having the nitrobenzyl substituent either on a corner or on the side of the macrocyclic ring. The origin of these two regioisomers appears to stem from a conformation of the ligand in solution in which it is hypothesized that pendant arms lie both above and below the plane of the macrocycle. The conformational changes that then result during the formation of the intermediate H2GdL+ chelate give rise to differing positions of the nitrobenzyl substituent depending upon from which face of the macrocycle the Ln3+ approaches the ligand.
Tircso, Gyula,Webber, Benjamin C.,Kucera, Benjamin E.,Young, Victor G.,Woods, Mark
p. 7966 - 7979
(2011/10/09)

Comparison of covalency in the lanthanide chloride and nitrate complexes based on the adsorption data on zeolite y
The changes of the distribution constants Kd of lanthanide chlorides in the system: zeolite Y (solid phase)-sodium chloride (aqueous phase) were investigated. The evident tetrad effect in the change of log Kd values within the lantha
G?adysz-P?aska, Agnieszka,Majdan, Marek,Ferenc, Wies?awa,Sarzyński, Jan
p. 469 - 474
(2012/03/22)

Variations modulo 4-4+, 4+3 -3+4-, 4-5+, 5 -4+4-5+4-4+ with rare earth carbide halides
The new compounds Pr8(C2)4Cl5 (1), Pr14(C2)7Cl9 (2), Pr 22(C2)11Cl14 (3), Ce 2(C2)Cl (4), La2(C2)Br (5), Ce 2(C2)Br (6), Pr2(C2)Br (7), Ce 18(C2)9Cl11 (8), and Ce 26(C2)13Cl16 (9) were prepared by heating mixtures of LnX3, Ln and carbon or in an alternatively way LnX3, and Ln2C3-x in appropriate amounts for several days between 750 and 1200 °C. The crystal structures were investigated by X-ray powder analysis (5-7) and/or single crystal diffraction (1-4, 8, 9). Pr8(C2)4Cl5 crystallizes in space group P21/c with the lattice parameters a = 7.6169(12), b = 16.689(2), c = 6.7688(2) A, β = 103.94(1) °, Pr14(C2)7Cl9 in Pc with a = 7.6134(15), b = 29.432(6), c = 6.7705(14) A, β = 104.00(3) °, Pr22(C2)11Cl14 in P21/c with a = 7.612(2), b = 46.127(9), c = 6.761(1) A, β = 103.92(3) °, Ce2(C2)2Cl in C2/c with a = 14.573(3), b = 4.129(1), c = 6.696(1) A, β = 101.37(3) °, La 2(C2)2Br in C2/c with a = 15.313(5), b = 4.193(2), c = 6.842(2) A, β = 100.53(3) °, Ce2(C 2)2Br in C2/c with a = 15.120(3), b = 4.179(1), c = 6.743(2) A, β = 101.09(3) °, Pr2(C2) 2Br in C2/c with a = 15.054(5), b = 4.139(1), c = 6.713(3) A, β = 101.08(3) °, Ce18(C2)9Cl 11 in Pβar{1}$ with a = 6.7705(14), b = 7.6573(15), c = 18.980(4) A,α = 88.90(3) °, β = 80.32(3) °, γ = 76.09(3) °, and Ce26(C2)13Cl16 in P21/c with a = 7.6644(15), b = 54.249(11), c = 6.7956(14) A, β = 103.98(3) ° The crystal structures are composed of Ln octahedra centered by C2 dumbbells. Such Ln6(C 2)-octahedra are condensed into chains which are joined into undulated sheets. In compounds 1-4 three and four up and down inclined ribbons alternate (4+4-, 4+3-3 +4-, 4+4-3+4 -4+3-), in compounds 8 and 9 four and five (4+5-, 5+4-4+5 -4+4-), and in compounds 4-7 one, one ribbons (1+1-) are present. The Ln-(C2)-Ln layers are separated by monolayers of X atoms. Copyright
Mattausch, Hansjuergen,Simon, Arndt
p. 1093 - 1100
(2011/09/13)

Destabilization of LiBH4 by (Ce, La)(Cl, F)3 for hydrogen storage
The mixtures of LiBH4 with halides of Ce or La in a molar ratio of 3:1 were investigated to explore their hydrogen storage properties. The ball milling of LiBH4 with chloride of Ce or La yielded Ce(BH 4)3 and La(BH4)3, while fluoride of Ce or La did not react with LiBH4 during extended ball milling at room temperature. The dehydrogenation temperatures of the ball-milled mixtures were reduced to 220-320 °C, which were much lower than that of pure LiBH4. The diborane emission during hydrogen release was observed at a low level. The dehydrogenation temperature is found to be affected by the composition of rare earth halides, but less influenced by ball milling time. The endothermic dehydrogenation reactions produced lithium halides, hydrides and borides of the corresponding rare earth element. Moreover, the LiBH4 + 1/3(Ce, La)(Cl, F)3 showed partial reversibility through the formation of an unknown borohydride, allowing for a potential hydrogen storage system.
Zhang, Bang Jie,Liu, Bin Hong,Li, Zhou Peng
p. 751 - 757
(2011/02/24)

Structural characterization of methanol substituted lanthanum halides
The first study into the alcohol solvation of lanthanum halide [LaX3] derivatives as a means to lower the processing temperature for the production of the LaBr3 scintillators was undertaken using methanol (MeOH). Initially the de-hydration of {[La(μ-Br)(H2O)7](Br)2}2 (1) was investigated through the simple room temperature dissolution of 1 in MeOH. The mixed solvate monomeric [La(H2O)7(MeOH)2](Br)3 (2) compound was isolated where the La metal center retains its original 9-coordination through the binding of two additional MeOH solvents but necessitates the transfer of the innersphere Br to the outersphere. In an attempt to in situ dry the reaction mixture of 1 in MeOH over CaH2, crystals of [Ca(MeOH)6](Br)2 (3) were isolated. Compound 1 dissolved in MeOH at reflux temperatures led to the isolation of an unusual arrangement identified as the salt derivative {[LaBr2.75·5.25(MeOH)]+0.25 [LaBr3.25·4.75(MeOH)]-0.25} (4). The fully substituted species was ultimately isolated through the dissolution of dried LaBr3 in MeOH forming the 8-coordinated [LaBr3(MeOH)5] (5) complex. It was determined that the concentration of the crystallization solution directed the structure isolated (4 concentrated; 5 dilute) The other LaX3 derivatives were isolated as [(MeOH)4(Cl)2La(μ-Cl)]2 (6) and [La(MeOH)9](I)3·MeOH (7). Beryllium Dome XRD analysis indicated that the bulk material for 5 appear to have multiple solvated species, 6 is consistent with the single crystal, and 7 was too broad to elucidate structural aspects. Multinuclear NMR (139La) indicated that these compounds do not retain their structure in MeOD. TGA/DTA data revealed that the de-solvation temperatures of the MeOH derivatives 4-6 were slightly higher in comparison to their hydrated counterparts.
Boyle, Timothy J.,Ottley, Leigh Anna M.,Alam, Todd M.,Rodriguez, Mark A.,Yang, Pin,Mcintyre, Sarah K.
p. 1784 - 1795
(2010/07/03)

Macrocyclic receptor exhibiting unprecedented selectivity for light lanthanides
We report a new macrocyclic ligand, N,N'-bis[(6-carboxy-2-pyridil)methyl]- 4,13-diaza-18-crown- 6 (H2bp18c6), designed for complexation of lanthanide ions in aqueous solution. Potentiometric measurements evidence an unprecedented selectivity of bp18c6 for the large LnIIIions. Among the different LnIII ions, LaIII and CeIII show the highest log KML values, with a dramatic drop of the stability observed from CeIII to LuIII asthe ionic radius of the LnIII ions decreases (log Cel- log KLul ) 6.9). The X-ray crystal structures of the GdIII and YbIII complexes show that the metal ion is directly bound to the10 donor atoms of the bp18c6 ligand. The structure of the complexes in solution has been investigated by 1H and 13C NMR spectroscopy, as well a s by theoretical calculations performed at the DFT (B3LYP) level. Our results indicate that a conformational change occurs around the middle of the lanthanide series: for the larger LnIII ions the most stable conformation is Δ( δ λδ)( δ λδ), while for the smallest LnIII ions (Gd-Lu) our calculations predict the Δ(λδ λ)( λδ λ form being the most stable one. This structural change was confirmed by the analysis of the Ce III-, PrIII-, and YbIII-induced paramagnetic 1H shifts. The selectivity that bp18c6 shows for the large LnIII ions can be attributed to a better fit between the light LnIII ions and the relatively large crown fragment of the ligand. Indeed, our DFT calculations indicate that the interaction between the LnIII ion and several donor atoms of the crown moiety is weakened as the ionic radius of the metal ion decreases.
Roca-Sabio, Adrian,Mato-Iglesias, Marta,Esteban-Gomez, David,Toth, Eva,Blas, Andres de,et al.
p. 3331 - 3341
(2009/07/30)

Stability, water exchange, and anion binding studies on lanthanide(III) complexes with a macrocyclic ligand based on 1.7-diaza-12-crown-4: Extremely fast water exchange on the Gd3+ complex
The picolinate-derivative ligand based on the 1,7-diaza-12-crown-4 platform (bp12c4 2-) forms stable Ln3+ complexes with stability constants increasing from the early to the middle lanthanides, then being relatively constant for the
Palinkas, Zoltan,Roca-Sabio, Adrian,Mato-lglesias, Marta,Esteban-Gomez, David,Platas-Iglesias, Carlos,De Blas, Andres,Rodriguez-Blas, Teresa,Toth, Eva
p. 8878 - 8889
(2009/12/25)

The first structure with isolated carbon-centered tetrahedra of rare-earth metals - The new compound Ce4CCl8
Ce4CCl8 is prepared by heating stoichiometric mixtures of cerium, CeCl3 and carbon in sealed tantalum capsules at 820 °C. It forms black polyhedral, in fragments transparent orange to red and moisture-sensitive crystals [s
Schaloske, Manuel C.,Kienle, Lorenz,Hoch, Constantin,Mattausch, Hansjurgen,Kremer, Reinhard K.,Simon, Arndt
p. 1023 - 1029
(2009/10/17)

MACROCYCLIC COMPOUNDS AND METHODS OF MAKING AND USING THEREOF
Described herein are tricyclic macrolactones. The macrolactones have a high binding affinity for PKC. The compounds described herein can be used in a number of therapeutic applications including cancer and Alzheimer's prevention and treatment. The compounds described herein can also treat memory loss. Also described herein are methods for producing macrolactones. The methods permit the high-yield synthesis of macrolactones in fewer steps and with a higher degree of substitution and specificity.
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Page/Page column 31-32

(2009/12/02)

Solubility behavior of rare earths with ammonium carbonate and ammonium carbonate plus ammonium hydroxide: Precipitation of their peroxicarbonates
The purpose of this work is to report the significant behavior of the rare earths when treated with ammonium carbonate and with a binary mixture of ammonium carbonate plus ammonium hydroxide. The carbonates of some rare earths are completely soluble in ammonium carbonate or in ammonium carbonate plus ammonium hydroxide, while others are only partially soluble and finally some are completely insoluble. Addition of hydrogen peroxide to the soluble complexed rare earth carbonates results in the precipitation of a series of a new compounds described as rare earth peroxicarbonates. The rare earths have some different precipitation behavior in the carbonate-peroxide system. Some are completely and immediately precipitated, others are completely precipitated after an aging period, and finally other are not precipitated at all. These different behaviors open a new possibility for the separation chemistry of the rare earths. Sm, Gd, Dy, Y, Yb and Tm are fast and completely soluble in ammonium carbonate. Ho, Eu and Tb are completely soluble in ammonium carbonate but slowly dissolved. La, Ce, Pr and Nd are only partially soluble in ammonium carbonate. While Ce, Pr, Nd, Sm, Eu and Dy are completely and easily soluble in the ammonium carbonate plus ammonium hydroxide mixture, La is only partially soluble and Tb is completely insoluble in the same mixture. Concerning the peroxicarbonates, La, Ce, Pr, Nd, Sm, Eu, Gd, Dy and Ho are quantitatively precipitated. The precipitation of the Er peroxicarbonate is quantitative, but after an aging period of 24 h. Y is not precipitated at all. The process is very easy, simple and economically attractive. Although proved in bench scale, its scale-up is easily feasible.
de Vasconcellos, Mari E.,da Rocha,Pedreira,Queiroz, Carlos A. da S.,Abr?o, Alcídio
p. 426 - 428
(2008/10/09)

Comparison of thermal properties of lanthanide trimellitates prepared by different methods
By diffusion in gel medium new complexes of formulae: Nd(btc) ·6H2O, Gd(btc)·4.5H2O and Er(btc)?5H2O (where btc=(C6H3(COO)33-) were obtained. Isomorphous compounds were crystallized in the
Lyszczek, Renata
p. 833 - 838
(2009/02/07)

The oxide nitride selenides M3ONSe2 of trivalent lanthanoids (M = Ce - Nd)
Oxide nitride selenides of the trivalent lanthanoids (M = Ce - Nd) with the composition M3ONSe2 can be prepared by the oxidation of the respective lanthanoid metal with selenium and sodium azide (NaN3) in presence of impurities containing oxygen when the corresponding lanthanoid trichloride (MCl3) is used as sodium trap for the coformation of NaCl. The thermal treatment of these mixtures along with additional NaCl as flux at 900°C in evacuated silica tubes secures the formation of fawn, transparent, lath-shaped crystals. The monoclinic structure (C2/m, Z = 6) was determined from X-ray single-crystal diffraction data (Ce3ONSe 2: a = 2480.51(14), b = 406.85(3), c = 952.83(6) pm, β = 95.506(4)°; Pr3ONSe2: a = 2462.72(14), b = 403.74(3), c = 947.26(6) pm, β = 95.731(4)°; Nd3ONSe2: a = 2440.35(14), b = 401.48(3), c = 944.02(6) pm, β = 95.763(4)°). Five crystallographically different M3+ cations reside in six- to eightfold coordination of the respective anions (three independent O 2-/N3- and Se2- each), for which a statistic distribution of the light elements (O2- : N3- = 1 : 1) has to be assumed. However, the main features of the crystal structure are (O 2-/N3-)-centred (M3+)4 tetrahedra. For the first time ever within the same structure of this kind, condensation of these anion-centred cation polyhedra forming strands and layers simultaneously could be detected. Cis-edge connected [(O/N)M4]9.5+ tetrahedra build up the chain components ∞1{[(O/N) (M4)3/3(M5)1/1]3,5+} running along [010], which are already known as dominating core in some crystal structures of pure nitride chalcogenides (e.g. Sm4N2S3 and Tb 4N2Se3). A new motif of condensed tetrahedral units comprises the second feature. By fusing [(O/N)M4] 9.5+ tetrahedra via vertices and edges, one-dimensional strand sections from the cationic sheets ∞2{([OCe 4/4]+)2} of the Ce2O 2S-type structure, which are further connected only via common vertices to form a lower-condensed steplike two-dimensional layer ∞2{[(O/N)4M5]5+}, spreading parallel to the (100) plane, emerge for the very first time.
Lissner, Falk,Schleid, Thomas
p. 2799 - 2804
(2009/05/30)

Bridgman growth of LaCl3:Ce3+ crystal in non-vacuum atmosphere
Growth of LaCl3:Ce3+ crystal by the vertical Bridgman process in non-vacuum atmosphere has been studied. Based on the dehydration procedure of LaCl3·7H2O and CeCl3·7H2O investigated by DTA/TG, anhydrous LaCl3 and CeCl3 were prepared by heating LaCl3·7H2O and CeCl3·7H2O at 200-230 °C for 6-7 h in dried HCl atmosphere. Using the feed materials prepared from the anhydrous lanthanon chlorides, a 4 mol% Ce3+ doped LaCl3 crystal with a size of ? 28 mm × 70 mm was successfully grown. The crystal was grown under the optimum conditions such as a growth rate of 0.5-0.8 mm/h and a temperature gradient of around 30 °C/cm across solid-liquid interface at a furnace temperature of 940-960 °C. The Bridgman process is confirmed to be promising for growing large size LaCl3:Ce3+ crystals with high quality.
Chen, Hongbing,Yang, Peizhi,Zhou, Changyong,Jiang, Chengyong
p. 172 - 175
(2008/10/09)

A systemic study of stepwise chlorination-chemical vapor transport characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by alkaline chlorides as complex former
A systematic study has been carried out for the stepwise chlorination-chemical vapor transport (SC-CVT) characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes KLnCl4 and NaLnCl4 (Ln = Sc, Y and La-Lu) used NaCl and KCl as complex former, respectively. The results showed that the SC-CVT characteristics are similarly for NaCl and KCl as complex former, the main deposition temperature of the rare earth chlorides LnCl3 is in the increasing order ScCl3 3 3, and then with a systematically decreasing trend from the early lanthanide chlorides to the end one. The results also showed that the total transported amount of the produced chlorides is YCl3 > ScCl3, and they are much higher than that of most lanthanoid chlorides. For lanthanoids, the total transported amount of chloride increases systematically from the early lanthanoid chlorides to the end one except for EuCl3 and GdCl3 mediated by KCl and NaCl as complex former, respectively, which showed the divergence effect of Gd in the total transport efficiency. But there are some differences in SC-CVT characteristics of pure rare earth oxide mediated by KCl and NaCl as complex former, that is the main deposition temperature region for the same rare earth element was lower for KCl than that for NaCl as complex former except for LaCl3, CeCl3, YbCl3 and LuCl3, while the total transport amount of rare earth chloride for KCl as complex former is higher than that for NaCl except for LaCl3 and EuCl3. More over, the discussion was carried out for Sc and Y on the one hand and the lanthanides contain 4f electron as another hand based on the 4f electron hybridization assumption. Further more, the transport characteristics of rare earth oxides with alkaline chlorides as complex former in this study were compared to that with AlCl3 as complex former.
Sun, Yan-Hui,He, Peng,Chen, Hua-Ni
p. 352 - 358
(2008/10/09)

Equilibria and structure of the lanthanide(III)-2-hydroxy-1,3- diaminopropane-N,N,N′,N′-tetraacetate complexes: Formation of alkoxo-bridged dimers in solid state and solution
The complex formed between 1,3-diamino-2-hydroxypropane-N,N,N′, N′-tetraacetic acid (H4L-OH) and Nd3+ at pH 7.5 was found to be a dinuclear dimer in the solid state by X-ray crystallography. In the complex K4[Nd2(L-O)2-(H2O) 2]-14H2O each ligand is coordinated to both Nd 3+ atoms with an iminodiacetate group (the Nd3+-Nd 3+ distance is 3.9283(8) A). The alcoholic OH groups are deprotonated, and the alkoxo oxygens are coordinated to both Nd3+ in a bridging position. The Nd3+ ions are nine-coordinated with one water molecule per Nd(III) ion in the inner sphere. The complex K 4[Nd2(L-O)2(H2O)2] ·14H2O has an inversion center, and the space group is P1. Two of the K+ counterions are six-coordinated, while the other two K+ ions are eight-coordinated; polar polymeric water-K+ layers are formed between the apolar ligand layers via the bridging water molecules. The dinuclear dimer complexes are also present in aqueous solution. The proton relaxivities of the Gd3+ complex decrease with the increase of pH, and at pH > 6, the low relaxivity values indicate the probable absence of H2O in the inner sphere and the predominance of the eight-coordinated dimer species [Gd2(L-O)2]. 4- The results of ESI-TOF MS studies of the complexes of La 3+, Nd3+, and Lu3+ proved the formation of dinuclear dimers in dilute (0.25 mM) solutions. pH-potentiometric titrations indicate the formation of complexes with 1:1 (Ln(L-OH)-, Ln(HL-OH), and Ln2(L-O)24-) and 2:1 (Ln 2(L-O)+) metal-to-ligand ratios. The stability constants of the Ln(L-OH)- species increase from La3+ (log K = 10.19) to Lu3+ (log K = 14.08). The alcoholic OH group of the Ln(L-OH)- species dissociates at unusually low pH values. The pH range of dissociation shifts to lower and lower pH's with the increasing atomic number of the lanthanides. This pH range is about 4-7 for the La3+ complex and 1-4 for the Lu3+ complex. The results of 1D and 2D 1H and 13C NMR studies of the La3+ complex, the number and multiplicity of signals, and the values of coupling constants are in agreement with the dinuclear dimer structure of the complex in solution.
Tircso, Gyula,Benyei, Attila,Bruecher, Erno,Kis, Anita,Kiraly, Robert
p. 4951 - 4962
(2008/10/09)

Luminescent CeCl3 nanoparticles by Tris(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)cerium diglyme photolysis in chlorinated solvents
Irradiation of [Ce(hfac)3(diglyme)] (hfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato and diglyme (DG) = 2,5,8,11,14-pentaoxapentadecane) in chlorinated solvents (CH2Cl2, CCl4) with UV light led to luminescent colloidal CeCl3 that was characterized by transmission electron microscopy (TEM) analysis. When a substrate, quartz or silicon was present in the reaction cell, photoluminescent films were obtained, containing either pure CeCl3 or mixtures of CeCl3, CeF3 and CeOx in function of the experimental parameters of irradiation. Nanostructured and luminescent pure CeCl3 films were obtained by irradiation of the cerium complex in CCl4 at high intensity light for a few minutes. The films were characterized by X-ray diffraction (XRD), Energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), TEM, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The kinetics of the [Ce(hfac)3(diglyme)] solution photodegradation, followed by UV spectrophotometry and spectrofluorimetry, pointed to CeCl3 formation by a solvent-initiated reaction, whereas the other inorganic compounds were the products of side reactions.
Giuffrida, Salvatore,Condorelli, Guglielmo G.,Costanzo, Lucia L.,Ventimiglia, Giorgio,Favazza, Maria,Petralia, Salvatore,L. Fragalà, Ignazio
p. 4043 - 4052
(2008/10/09)

Synthesis, structure, and 15N NMR studies of paramagnetic lanthanide complexes obtained by reduction of dinitrogen
The recently discovered LnZ3/M and LnZ2Z′/M methods of reduction (Ln = lanthanide; M = alkali metal; Z, Z′ = monoanionic ligands that allow these combinantions to generate "LnZ 2" reactivity) have been applied to provide t
Evans, William J.,Rego, Daniel B.,Ziller, Joseph W.
p. 10790 - 10798
(2008/10/09)

Effect of reaction temperature on the chlorination of a Sm 2O3-CeO2-C mixture
The chlorination of a Sm2O3-CeO2-C mixture with gaseous chlorine was studied by thermogravimetry (TG). The effect of the reaction temperature between 400 and 950°C on the reaction rate was analyzed. The reaction products were studied by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). Compared to the results previously found in the individual systems, it was concluded that each oxide evolves as being an individual in the mixture. Combined with TG results along with observations done using scanning electron microscopy (SEM), the stoichiometries of the reactions involved were obtained. From these results, a two-stage separation method for both oxides was proposed.
Esquivel,Bohé,Pasquevich
p. 47 - 55
(2008/10/09)

Extraction of lanthanide chlorides by binary extractants based on phosphinic acid derivatives
The extraction of lanthanide chlorides by methyltrioctylammonium dialkylphosphinate, dialkyl-monothiophosphinate, or dialkyldithiophosphinate in toluene was studied. In all cases, extractable MA3 compounds were formed in an organic phase. The extractability of metals increased in the order La a considerable effect on the distribution of the lanthanide salts. The extraction capacity of the binary extradants toward lanthanum chloride decreased in the order methyltrioctylammonium dialkylphosphinate > methyltrioctylammonium dialkylmonothiophosphinate > methyltrioctylammonium dialkyldithiophosphinate. Copyright
Egorova,Belova,Voshkin,Zhilov,Khol'kin
p. 1781 - 1784
(2008/10/09)

CeO2 nanorods and gold nanocrystals supported on CeO2 nanorods as catalyst
The formation mechanism of uniform CeO2 structure at the nanometer scale via a wet-chemical reaction is of great interest in fundamental study as well as a variety of applications. In this work, large-scale well-crystallized CeO2 nanorods with uniform diameters in the range of 20-30 nm and lengths up to tens of micrometers are first synthesized through a hydrothermal synthetic route in 5 M KOH solution at 180 ?°C for 45 h without any templates and surfactants. The nanorod formation involves dehydration of CeO2 nanoparticles and orientation growth along the ???110??? direction in KOH solution. Subsequently, gold nanoparticles with crystallite sizes between 10 and 20 nm are loaded on the surface of CeO 2 nanorods using HAuCl4 solution as the gold source and NaBH4 solution as a reducing agent. The synthesized Au/CeO 2 nanorods demonstrate a higher catalytic activity in CO oxidation than the pure CeO2 nanorods. ? 2005 American Chemical Society.
Huang,Wu,Zhu,Gao,Zhu,Yan,Huang,Wu,Song
p. 19169 - 19174
(2008/10/09)

La9Sb16Br3 and Ce9Sb 16Cl3: Stars and stripes in rare earth halide and intermetallic compounds
The title compounds were synthesized from Ln, LnX3 (Ln = La, Ce; X = Cl, Br), and Sb under an Ar atmosphere at 950°C. They crystallize in the space group P63/m (No. 176) with lattice constants a = 21.232(5) and 20.862(2) A and c = 4.323(2) and 4.2728(7) A for La9Sb 16Br3 and Ce9Sb16Cl3, respectively. The solids are the most metal-rich members in the reduced rare earth metal halide family and contain partial structures which are characteristic of reduced halides and intermetallic phases. These are the [Ln6X6]∞, hexagon stars, Sb-centered [Ln3Sb]∞ trigonal prismatic columns, and stripes of Sb square meshes. Computational analysis indicates that their electronic structure is valence-precise in the reduced halide part, but electron-deficient in the intermetallic part. Susceptibility and resistivity measurements reveal the metallic nature of the compounds.
Zheng, Chong,Mattausch, Hansjuergen,Simon, Arndt
p. 3684 - 3689
(2008/10/09)

1D-Polyoxometalate-Based Composite Compounds - Design, Synthesis, Crystal Structures, and Properties of [{Ln(NMP)6}(PMo12O 40)]n (Ln = La, Ce, Pr; NMP = N-methyl-2-pyrrolidone)
The structures of three 1:1 composite compounds prepared with the polyoxometalate (POM) [PMo12O40]3- and the cations [Ln(NMP)6]3+ [Ln = La (1), Ce (3), Pr (2); NMP = N-methyl-2-pyrrolidone] exhibit two types of zig-zag chains with alternating cations and anions through Mo-Ot-Ln-Ot-Mo links in the crystal. The compounds were characterized by IR, UV, and ESR spectroscopy, single-crystal X-ray structural analysis, and by a study of their thermal properties. In all the compounds, the La3+, Pr3+, and Ce3+ centers are eight-coordinate with the oxygen atoms in bicapped trigonal-prismatic geometries. The variation of the average Ln-O separations along the La, Ce, and Pr series is consistent with the effects of the lanthanide contraction. The results of the single-crystal X-ray diffraction analyses and the IR spectroscopic studies are in agreement and both show the metal cation units are coordinatively bonded to the Keggin clusters. The UV spectra of the title compounds suggest that their structures are entirely disrupted in dilute solution. Low-temperature ESR spectra indicate that thermal electron delocalization occurs among the Mo atoms in the three compounds. The results of cyclic voltammetry (CV) show that compounds 1, 2, and 3 all undergo five two-electron reversible reductions and that the [PMo12O 40]3- anions are the active centers for electrochemical redox reactions in solution, while the corresponding cations have only a small effect on the electrochemical properties. Studies of magnetic properties show that 1 is diamagnetic, while 2 and 3 exhibit antiferromagnetic Pr-Pr or Ce-Ce exchange interactions. In addition to the results of CV, the average bond lengths and the magnetic properties of compound 3 indicate that the oxidation state of cerium is iii in the compound of formula [{Ce(NMP) 6}(PMo12O40)]n. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Niu, Jing-Yang,Wei, Mei-Lin,Wang, Jing-Ping,Dang, Dong-Bin
p. 160 - 170
(2007/10/03)

Lanthanide contraction and pH value controlled structural change in a series of rare earth complexes with p-aminobenzoic acid
A series of rare earth complexes with p-aminobenzoic acid (HL) have been synthesized: [RE2L6(H2O)2] n [RE=La (1), Ce(2), Pr(3), Sm(4), Eu(5), Tb(6), Dy(7), Er(9)] and [RE2L6(H2O)4]·2H 2O [RE=Tb(6′), Ho(8), Yb(10), Lu(11), Y(12)]. The crystal structures of 1, 2, 6, 6′, 7, 9 and 12 have been determined and the isomorphous relationships of the others have been identified. Their structures change from two-dimensional (2D) array (the coordination number of the metal ions is nine for 1 and eight for 2-7 and 9) to double-nuclear structure (the metal ions are eight-coordinated) for 6′, 8 and 10-12, as controlled by lanthanide contraction. The structural type has been found influenced by the pH value of the reaction mixtures.
Sun, Hao-Ling,Ye, Chao-Hong,Wang, Xin-Yi,Li, Jun-Ran,Gao, Song,Yu, Kai-Bei
p. 77 - 83
(2007/10/03)

Method for preparing oestrogen derivatives
A process for the preparation of compounds of formula (I) in which R1, R2, R3 and n are defined as indicated in the description, use of said compounds as intermediates for the preparation of estrogen derivatives as well as the intermediates of this process.
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Page/Page column 6

(2010/02/08)

Chlorination of cerium dioxide
The chlorination of cerium dioxide was studied by thermagravimetry under controlled atmosphere between 800 and 950 °C. An apparent activation energy of 190 kJ mol-1 was observed. To discriminate the effect of the vaporization of the CeCl3 on the chlorination rate, this process was also studied with the same technique between 850 and 950 °C. An apparent activation energy of 184 kJ mol-1 was determined. The CeO2 chlorination rate was found to be under a chemical-mixed control influenced by the vaporization of CeCl3.
Esquivel,Bohé,Pasquevich
p. 81 - 91
(2008/10/08)

Ce10Cl4Ga5 and Ln3ClGa4 (Ln = La, Ce): Reduced halides or oxidized intermetallics?
The compounds Ce10Cl4Ga5 and Ln3ClGa4 (Ln = La, Ce) were synthesized from stoichiometric mixtures of Ln, LnCl3, and Ga under Ar atmosphere in sealed Ta ampules at 910-1020 °C for 25-26 days. Ce10Cl4Ga5 is isostructural to La10Cl4Ga5 (space group 14/mcm, No. 140) with lattice constants a = 7.9546(11) A, c = 31.793(6) A. Ln3ClGa4 represents a new structural type, also in the space group 14/mcm, with a = 8.1955(8) and 8.1123(11) A, c = 11.363(2) and 11.229(2) A, respectively, for Ln = La and Ce. Ce10Cl4Ga5 features building blocks of Ga-centered Ce6 trigonal prisms and distinctive two-dimensional intermetallic CuAl2 and U3Si2 type nets. Its electronic structure falls within the realm of reduced rare-earth halides. Ln3ClGa4 also contains the intermetallic CuAl2 type nets, but the interstitials are inverted: The building blocks are Cl-centered Ln6 octahedra. Its electronic structure is characterized by strong peripheral Ln-Ga bonding stabilizing the Ln6Cl octahedron which normally would have its Ln-Ln antibonding orbitals filled with electrons from interstitials beyond chalcogen. Magnetic susceptibility and conductivity measurements confirm the metallic nature of all three compounds.
Zheng, Chong,Mattausch, Hansjurgen,Oeckler, Oliver,Simon, Arndt
p. 3130 - 3135
(2008/10/08)

Preparation of cerium hydrides
The conditions of the reaction between CeCl3 and LiH are optimized so as to obtain CeH2.73 or a mixture of β- and γ-CeH2.
Osadchaya,Sokolov,Trushnikova,Zubareva
p. 1142 - 1143
(2008/10/08)

Synthesis and characterization of volatile, fluorine-free β-ketoiminate lanthanide MOCVD precursors and their implementation in low-temperature growth of epitaxial CeO2 buffer layers for superconducting electronics
A new class of volatile, low-melting, fluorine-free lanthanide metal-organic chemical vapor deposition (MOCVD) precursors has been developed. The neutral, monomeric Ce, Nd, Gd, and Er complexes are coordinatively saturated by a versatile, multidentate ether-functionalized β-ketoiminato ligand series, the melting point and volatility characteristics of which can be tuned by altering the alkyl substituents on the keto, imino, and ether sites of the ligand. Direct comparison with conventional lanthanide β-diketonate complexes reveals that the present precursor class is a superior choice for lanthanide oxide MOCVD. Epitaxial CeO2 buffer layer films can be grown on (001) YSZ substrates by MOCVD at significantly lower temperatures (450-650 °C) than previously possible by using one of the newly developed cerium β-ketoiminate precursors. Films deposited at 540 °C have good out-of-plane (Δω = 0.85°) and in-plane (Δφ = 1.65°) alignment and smooth surfaces (rms roughness ～ 4.3 A). The film growth rate decreases and the films tend to be smoother as the deposition temperature is increased. High-quality yttrium barium copper oxide (YBCO) films grown on these CeO2 buffer layers by pulsed organometallic molecular beam epitaxy exhibit very good electrical transport properties (Tc = 86.5 K, Jc = 1.08 x 106 A/cm2 at 77.4 K).
Edleman, Nikki L.,Wang, Anchuan,Belot, John A.,Metz, Andrew W.,Babcock, Jason R.,Kawaoka, Amber M.,Ni, Jun,Metz, Matthew V.,Flaschenriem, Christine J.,Stern, Charlotte L.,Liable-Sands, Louise M.,Rheingold, Arnold L.,Markworth, Paul R.,Chang, Robert P. H.,Chudzik, Michael P.,Kannewurf, Carl R.,Marks, Tobin J.
p. 5005 - 5023
(2008/10/08)

Fusibility and Vaporization Diagrams of the Systems CeCl3-CoCl2 and CeCl3-FeCl2
Temperature plateaus during heating are measured experimentally for theCeCl3-FeCl2 and CeCl3-CoCl2 salt systems, the latter system being studied for the first time. The fusibility diagrams are determined experimentally for these systems which belong to the eutetic type. The validity ofthe measurements is verified by comparing the data presented in this work with those published for the CeCl3-FeCl2 system. The solid-liquid equilibrium lines for these systems are theoretically calculated using theSchroeder's equation. The calculated results prove that CeCl3-CoCl2 andCeCl3-FeCl2 are ideal systems. The saturated vapor pressure is measuredexperimentally for these systems, which additionally confirms the ideality of the CeCl2-CoCl2 and CeCl3-FeCl2 systems.
Kritskaya, E. B.,Burylev, B. P.,Moisov, L. P.,Kostenko, N. B.
p. 119 - 122
(2008/10/08)

New derivatives of the 1,2-benzodiazepine ring system
The adducts 10, formed in high yield by condensations between the benzotriazole dianion 2 and enals 9, undergo smooth oxidation by manganese(IV) oxide to provide the expected conjugated enones. These then cyclise at varying rates, depending upon the substitution pattern around the enone function, by intramolecular Michael addition of the NHBoc group to provide examples 13 of a novel ring system based upon a 4,5,6,7-tetrahydro-1,2-benzodiazepine core. Allylic acetates 16 derived from the initial adducts 10 also undergo cyclisations via the derived π-allyl palladium complexes 15 to provide examples of the corresponding 4,5-dihydro-1,2-benzodiazepinenes 17, but in a less general manner.
Knight, David W.,Little, Paul B.
p. 3752 - 3757
(2008/10/08)

Synthesis, characterization and anticoagulant action of lanthanide complexes of warfarin
Thirteen lanthanide complexes of warfarin, LnL3·nH2O [n = 6 (Ln = La-Yb) or n = 4 (Ln = Y); L = (C19H15O4)-] have been synthesized and characterized by elemental analyses, IR, 1H
Jiao, Tian Quan,Wu, Ji Gui,Zeng, Fu Li,Fu, Yun Long,Deng, Ru Wen
p. 725 - 735
(2008/10/09)

Comparative study for stepwise chlorination-chemical vapor transport characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes LnAlnCl3n+3
A systematic study has been carried out for the stepwise chlorination-chemical vapor transport (SC-CVT) characteristics of pure rare earth oxides from Sc2O3 to Lu2O3 mediated by the vapor complexes LnAlnCl3n+3 (where Ln = rare earth elements) under identical conditions. The results show that the total transported amount of the produced chlorides is the highest for YCl3; it is also high for ScCl3, but low for LaCl3, and then increases systematically from the early lanthanide chlorides to the end lanthanide chlorides except CeCl3, EuCl3 and GdCl3. The results also show that the main deposition temperature of the chlorides is in the increasing order ScCl3 3 3 and then with a systematically decreasing trend from the early lanthanide chlorides to the end lanthanide chlorides. Based on the literature data for the solid complexes LnAl3Cl12 and LnAl3Br12, a similar coordination structure assumption is introduced for the vapor complexes LnAl3Cl3n+3 from Ln = Sc to Ln = Lu with the same stoichiometry to explain the SC-CVT characteristics of the pure rare earth oxides from Sc2O3 to Lu2O3 using a 4f electron hybridization assumption.
Wang, Zhi-Chang,Sun, Yan-Hui,Guo, Lei
p. 109 - 113
(2008/10/08)

Use ofcerium(III) chloride in the reactions of carbonyl compounds with organolithiums or grignard reagents for the suppression of abnormal reactions:1-butyl-1,2,3,4-tetrahydro-1-naphthol
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Takeda, Nobuhiro,Imamoto, Tsuneo
p. 228 - 228
(2017/09/30)