Lanthanide Halides Research Articles

ChemInform Abstract: Synthesis and Structure of Gd4I5Si and Gd3I3Si: The First Examples of Reduced Rare Earth Halides Containing Second‐Row Non‐Metal Interstitial Atoms.

AbstractGd4I5Si (I) and Gd3I3Si are prepared by annealing appropriate mixtures of Gd, GdI3, and Si ((I): 1050 °C, 4 weeks; (II): 1100 °C, 2 weeks).

Regioselective hydrogenation of conjugated dienes catalyzed by hydridopentacyanocobaltate anion using .beta.-cyclodextrin as the phase transfer agent and lanthanide halides as promoters

{beta}-Cyclodextrin is a useful phase-transfer agent for the hydrogenation of conjugated dienes to monoolefins catalyzed by the in situ generated hydridopentacyanocobaltate anion. This reaction, which usually proceeds by 1,2-addition to the diene, is promoted by cerium or lanthanum chloride. Polyethylene glycol (PEG-400), with or without added lanthanide, can also be used as the phase-transfer agent for the reduction process.

Magnetic susceptibilities of rare-earth ions in an unusual tetrahedral site.

Magnetic susceptibilities of the series of compounds ${\mathrm{Cs}}_{2}$NaR(${\mathrm{NO}}_{2}$${)}_{6}$ have been measured for most of the rare earths (R) from Ce to Yb. These materials are cubic, with an unusual ${T}_{h}$ point symmetry at the rare-earth site. They exhibit not only many similarities but also interesting differences with the related, but octahedrally coordinated, rare-earth elpasolite halides. They are analyzed in terms of a lowest-order crystal-field theory.

Synthesis and structure of Gd 4I 5Si and Gd 3I 3Si: The first examples of reduced rare earth halides containing second-row non-metal interstitial atoms

Gd 4I 5Si and Gd 3I 3Si were prepared from gadolinium, GdI 3 and silicon at 1050–1100 °C in tantalum ampoules. The crystal structures were determined and are isotypic with Y 4I 5C and Gd 3Cl 3C (for Gd 4I 5Si C2/ m, Z = 2, a = 18.917 5(19) A ̊ , b = 4.1966(4) A ̊ , c = 8.7099(9) A ̊ , β = 103.298(8)°, R = 2.23% and R w = 1.81% ; for Gd 3I 3Si, I4 132, Z = 8, a = 12.052(2) A ̊ , R = 3.74% and R w = 3.33% ). Gd 4I 5Si and Gd 3I 3Si have cation-deficient NaCl structures and contain infinite one-dimensional chains and a three-dimensional network of edge-sharing silicon-centred gadolinium octahedra respectively. Results of structural analyses and extended Hückel molecular orbital band calculations are presented. The importance of the ionic interactions and the metal-metal and metal-silicon bonding is discussed as is the dimensionality of the structure in regard to the optimization of the size of the Gd 6 octahedra with the interstitial atom.

Stimulated emission from thulium bromide vapor

Stimulated emission was achieved for the first time due to atomic transitions in a rare-earth element by dissociation of vapor of a rare-earth element halide in a pulsed discharge. The range of existence of lasing due to the λ = 1448 nm transition in Tm I was studied in thulium bromide vapor.

An intermediate neglect of differential overlap (INDO) technique for lanthanide complexes: studies on lanthanide halides

An intermediate neglect of differential overlap method of use for examining the electronic structure of lanthanide complexes is developed. It is characterized by a basis set obtained from relativistic Dirac-Fock atomic calculations, the inclusion of all one-center two-electron integrals, and a parameter set based on molecular geometry. Lanthanide halides MX2, MX3 and MX4 are studied here, as well as initial results for the twelve coordinate Ce(NO3)6 −2 ion. Geometries obtained are in excellent agreement with experimental values when available. Many MX3 complexes are found to be pyramidal, and EuCl2 and YbCl2 are calculated to be bent even at the SCF level. Models invoking London type forces are therefore not required. Ionization potentials are calculated for the trihalides (δSCF) and are in reasonable agreement with experiment. Contrary to conclusion of others, f-orbital participation, although small, is required — at least in this model — to obtain the spread of metal to halide bond distance observed in these complexes. However f-orbital participation does not seem to be significant even in the twelve coordinate Ce(NO3)6 −2 complex: rather the large coordination number seems to be a consequence of the relatively large size of the lanthanide ion.

Study of the electronic structure of UBr4 using X-ray photoelectron spectroscopy

X-Ray photoelectron spectra of uranium and bromine core levels and valence bands have been recorded from UBr4 using a Kratos ES300 electron spectrometer. The spectra are compared to their counterparts recorded from UF4, UCl4 and UO2. The results obtained are discussed as a function of metal ionicity, covalency of the metal–ligand bond and the participation of 5f electrons in bonding. The satellite structure associated with the principal core levels in the early lanthanide and actinide halides are compared to the equivalent satellites observed in transition-metal halides and their origins are discussed.

X-Ray Photoelectron Spectroscopy of Rare Earth Halides

Abstract Rare earth (RE) halides (fluorides, chlorides, bromides, and iodides) have been studied by X-ray photoelectron spectroscopy. The binding energies (BE’s) of the RE 3d and 4d peaks for the chlorides, bromides, and iodides are related to the atomic charge calculated on the basis of Pauling’s scale of electronegativity (Pauling charge). Except for Y and Lu, the observed RE 3d and 4d BE’s for the fluorides are lower than those expected. For Y and Lu, the observed RE 3d and 4d BE’s for all halides are related to the Pauling charge. For the fluorides and chlorides, the BE’s of the ligand peak show variations with increasing atomic number of RE’s and a specific “tetrad effect” is observed in plots of BE versus RE atomic number and versus 1/R (where R is the mean distance from the ligand atom to the neighboring RE atom), except for the BE’s of the F 1s peaks from the light RE fluorides. For the iodides and bromides, no or little characteristic variations are seen in the BE’s of I and Br.

Spectroscopic study of rare earth chlorocomplexes in methanol and mixed methanol-water solvents

A new spectroscopic method for the investigation of rare earth halides in methanolic solutions is used to determine the effects of the solvent and solvation on the stability, electronic spectra and structures of individual rare earth chlorocomplexes. A numerical treatment of several thousand experimental optical density data covering all absorption ranges in the UV, visible and near IR is performed. Several possible models of the constitution of the solutions are tested to ensure the uniqueness of the conclusions. In methanol, the stabilities of LnCl 2+ and LnCl 2 2+ (Ln ≡ Pr, Nd, Sm) are a maximum for the neodymium complexes; the presence of water in the mixed methanol-water solvents leads to a decrease in the number and stabilities of the rare earth chlorocomplexes.

A simple empirical analysis of the enthalpies of formation of lanthanide halides and oxides

The author proposes a simple and general method whereby the lattice energies of lanthanide (II) and (IV) compounds are derived directly from those found experimentally for the corresponding lanthanide (III) compounds.

ChemInform Abstract: TERNARY RARE‐EARTH HALIDES OF THE A2MX5 TYPE (A = K, IN, NH4, RB, CS; X = CL, BR, I)

AbstractDie Titelverbindungen werden nach bereits beschriebenen und hier nur kurz skizzierten Verfahren dargestellt, wobei von In2PrCl5, Rb2PrCl5, KZPrBrS und KZPrIS Einkristalle, von den übrigen AzMxs‐Verbindungen Pulverproben erhalten werden, die röntgenographisch untersucht werden.

Empty, filled, and condensed metal clusters

Aspects of structure, bonding, physical, and chemical properties are discussed for (a) compounds containing discrete empty clusters and clusters with interstitial H atoms: Nb6I11, HNb6I11, HCsNb6I11, (b) metal-rich lanthanide halides and halide carbides,-nitrides and -hydrides, focusing on the role of interstitial atoms: Gd2Br2C2, Gd2Br2C, Gd3Cl3C, Gd10Cl18C4, Gd10Il17C4, Gd10I16C4, GD2Cl3N, GdXHn (X=Cl, Br, I; 0.6<n<0.9), GdBrD2; (c) metal-rich oxides of the alkali metals rubidium and cesium. Chemical bonding in the suboxide clusters Rb9O2 and Cs11O3 is discussed along the lines valid for (a) and (b) and covers recently described “hypervalent” species as Li6C, Li4O, etc.

Enthalpies of mixing of some binary liquid mixtures of rare earth halides

Enthalpies of mixing of some binary liquid mixtures of rare earth halides

Raman spectroscopy of superionic solid solutions of alkaline-earth and rare-earth halides

Raman spectroscopy of superionic solid solutions of alkaline-earth and rare-earth halides

ChemInform Abstract: THERMOCHEMICAL STUDIES OF MIXTURES OF SOME LANTHANIDE HALIDES WITH COPPER(I) CHLORIDE, SILVER CHLORIDE, AND THALLIUM(I) CHLORIDE

Chemischer InformationsdienstVolume 14, Issue 48 Physical Inorganic Chemistry ChemInform Abstract: THERMOCHEMICAL STUDIES OF MIXTURES OF SOME LANTHANIDE HALIDES WITH COPPER(I) CHLORIDE, SILVER CHLORIDE, AND THALLIUM(I) CHLORIDE R. BLACHNIK, R. BLACHNIKSearch for more papers by this authorE. ENNINGA, E. ENNINGASearch for more papers by this author R. BLACHNIK, R. BLACHNIKSearch for more papers by this authorE. ENNINGA, E. ENNINGASearch for more papers by this author First published: November 29, 1983 https://doi.org/10.1002/chin.198348023AboutPDF 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. Volume14, Issue48November 29, 1983 RelatedInformation

Reduced ternary rare earth halides: State of the art

Since the first discovery of Gd 2Cl 3 in 1964, a plethora of reduced binary rare earth halides with formal oxidation states less than 2 + has been obtained. Their common structural feature is an M 6 metal cluster surrounded by halide ions and, whenever necessary, edge connected. At present this appears to have no analogy in reduced ternary rare earth halide chemistry. Compounds with the oxidation state 2 + have been obtained for europium, ytterbium, samarium, thulium, dysprosium and scandium. The formula types AMX 3, A 2MX 4 and AM 2X 5 have been observed. AMX 3 compounds are either of the perovskite type ( e.g. cubic CsTmCl 3 or RbTmCl 3 with three modifications and two transitions near 185 and 375 °C) or isotypic with CsNiCl 3 (scandium(II) halides AScX 3 with A ≡ Cs, Rb, X ≡ Cl, Br and CsScI 3). A 2MX 4 compounds (examples are Cs 2YbCl 4 and Cs 2TmCl 4) are isostructural with K 2NiF 4 which is related to the perovskite structure. Samarium(II) and europium(II) halides of the AM 2X 5 type ( e.g. KSm 2Cl 5) are structurally closely related to K 2SmCl 5. In KSm 2Cl 5 (equivalent to KSm[SmCl 5]) samarium(II) has coordination numbers of 8 and 7. The successful synthesis of ternary scandium(II) halides gave a first indication that there is a possibility of producing ternary reduced halides with other than the four classical divalent rare earths. The example LiDy 2Cl 5 (with coordination numbers of 8 for dysprosium(II) and 6 for lithium) which was obtained via lithium metal (metallothermic) reduction of DyCl 3 clearly shows that the production of further compounds is possible.

Metal-metal bonding with reduced halides and halide carbides of rare earth metals

Special aspects of a d metal chemistry of low valent lanthanide halides (metal clusters, condensed clusters, heteroatoms in clusters) are discussed.

The synthesis and structures of complex rare-earth halides

The subject is reviewed under the following headings: introduction; nomenclature and definitions; the divalent state: A/sup +1/sub(w)Re/sup +2/sub(y)X/sup -1/sub(z) (synthesis; ARE/sub 2/X/sub 5/ compounds; AREX/sub 3/ compounds; A/sub 2/REX/sub 4/ compounds); in between: A/sup +2/sub(w)RE/sup +3/sub(y)X/sup -1/sub(z); the trivalent state: A/sup +1/sub(w)RE/sup +3/sub(y)X/sup -1/sub(z) and A/sup +1/sub(w)B/sup +1/sub(x)RE/sup +3/sub(y)X/sup -1/sub(z) (synthesis; ARE/sub 2/X/sub 7/ compounds; A/sub 2/REX/sub 5/ compounds: inohalides; the monohydrates: A/sub 2/RECl/sub 5/.H/sub 2/O; close-packed structures and derivatives; volume chemistry; the elpasolites: A/sub 2//sup +1/B/sup +1/RE/sup +3/X/sub 6//sup -1/; A/sub 3/RE/sub 2/X/sub 9/ compounds: sorohalides; A/sub 3/REX/sub 6/ compounds: nesohalides; a survey of the complex rare-earth fluorides); the tetravalent state (synthesis; A/sub 3/REF/sub 7/ and A/sub 2/BREF/sub 7/ compounds; miscellaneous compounds); references.

Magnetic properties of reduced rare earth halides

Magnetic properties of reduced rare earth halides

希土類ハロゲン化物入りメタルハライドランプの発光特性

希土類ハロゲン化物入りメタルハライドランプの発光特性