- Synthesis and crystal structure of (NH4)3Cu4Ho2Br13. Further bromides of the (NH4)3Cu4M2Br13 Type (M = Dy-Lu, Y) and on Rb3Cu4Ho2Br13
-
Single crystals of (NH4)3Cu4Ho2Br13 were obtained for the first time from the reaction of CuBr with HoBr3 which was contaminated with NH4Br: cubic, space group Pn3, Z = 2, a = 1101.71(5) pm. The crystal structure may be considered as a variant of the fluorite type according to [(HoBr6)4] [(NH4)6Cu4Br)2] ≡ Ca4F8. Pure products can be prepared from the binary halides in glass ampoules at 350°C. The bromides (NH4)3Cu4M2Br13 (M = Dy-Lu, Y) and Rb3Cu4Ho2Br13 are isotypic with (NH4)3Cu4Ho2Br13. Johann Ambrosius Barth 1996.
- Wickleder, Mathias S.,Bohnsack, Andreas,Meyer, Gerd
-
-
Read Online
- 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)
-
- Systematics and anomalies in rare earth/aluminum bromide vapor complexes: Thermodynamic properties of the vapor complexes LnAl3Br12 from Ln = Sc to Ln = Lu
-
Systematics and anomalies in the rare earth/aluminum bromide vapor complexes have been investigated by the phase equilibrium-quenching experiments. The measurements suggest that the LnAl3Br12 complexes are the predominant vapor compl
- Wang, Zhi-Chang,Yu, Jin
-
p. 4248 - 4255
(2008/10/09)
-
- Vibrational modes and structure of rare earth halide-alkali halide binary melts YBr3-ABr (A = Li, K, Cs) and YF3-KF
-
Raman spectra of the following binary molten salt systems have been measured: (a) YBr3-ABr (A = Li, K, Cs) at temperatures up to 920 °C and at different compositions; (b) YF3-KF at temperatures up to 1000 °C and compositions up to 50% YF3. The spectral changes occurring upon melting of Cs2NaYBr6, YBr3 and K3YF6 crystalline compounds were also measured. The data indicate that, in mixtures rich in alkali halide, YXg (X = F, Br) octahedra are the predominant species giving rise to two main bands Pt (polarized) and Dt (depolarized) which are assigned as follows: (a) YBrg , P: = 156 cm 1, vt(Alg) and Dt = 78 cm 1, vs (F2g); and (b) YF , Pj = 445 cm 1, Vj(Alg) and Dt = 225 cm 1, v5(F2g). In molten mixtures rich in YBr3 in addition to the P! and D! bands a new depolarized D2 (ca. 210 cm 1) and a strong new polarized P2 band appear in the spectra. The P2 band shifts from ca. 200 cm 1 to ca. 250 cm 1 with increasing YBr3 content. The presence of these four bands and their polarization characteristics suggest that the predominant vibrational modes in the YBr3-rich mixtures are due to a close C3v pyramidal like 'unit' arising from the ￡>3 distortions of the YBr octahedra bound by edges in the melt. This behaviour, as well as the spectral changes upon melting YBr3, supports the view that the structure of pure molten YBr3 consists of edge-sharing distorted octahedra. The molten fluoride mixtures YF3-KF at composition A YFj > 0.25 also show four bands, two depolarized at ca. 240 cm 1 (Dj), ca. 370 cm 1 (D2) and two overlapping polarized bands at ca. 440 cm 1 (Pj), ca. 460 cm 1 (P2). Finally, the trends of the YX3-KX spectra on going from the bromide to chloride to fluoride melts suggest that pure molten YF3 is likely to possess a loose 'network' structure of edge-bridged distorted octahedra as in the case of molten YC13 and YBr3.
- Dracopoulos,Gilbert,Borrensen,Photiadis,Papatheodorou
-
p. 3081 - 3088
(2007/10/03)
-
- Oligomeric Rare-Earth-Metal Halide Clusters. Three Structures Built of (Y16Z4)Br36 Units (Z = Ru, Ir)
-
Suitable reactions in sealed Nb tubing at 850-950 °C gave good yields of a family of oligomeric cluster phases that were characterized by single-crystal X-ray diffraction means. The basic Y16Z4 units (?4? symmetry) can be derived from 2+2 condensation of centered Y6Br12Z-type clusters or as tetracapped truncated tetrahedra Y16 that are centered by a large tetrahedral Z4. These are surrounded by 36 bromine atoms which bridge edges or cap faces of the Y16Z4 nuclei and, in part, bridge to metal atoms in other clusters. The principal bonding appears to be Y-Z and Y-Br, with weaker Y-Y (d ? 3.70 A?) and negligible Z-Z interactions. The phase Y16Br20Ru4 (P42/nnm, Z = 2; a = 11.662(1) A?, c = 16.992 (2) A?) is isostructural with Y16I20Ru4 and with the new Sc16-Br20Z4 (Z = Fe, Os). Syntheses only in the presence of Ir and ABr-YBr3 fluxes (A = K-Cs) produce Y16-Br24Ir4 (Fddd, Z = 8; a = 11.718(3) A?, b = 22.361(7) A?, c = 44.702(2) A?), in which the electron-richer Ir interstitials are compensated by four additional bromine atoms and altered bridging between macroclusters. Larger amounts of YBr3 yield a third example, Y20Br36Ir4 (Y16Br24Ir4·4YBr3, I41; a, Z = 4; a = 12.699(1) A?, c = 45.11-(1) A?). Here infinite zigzag chains of YBr6/2 octahedra that share cis edges lie between and bridge to the Y16Ir4 clusters. All of these phases contain 60-electron, closed-shell macroclusters. Y16Br20Ru4 and Y20Br36Ir4 were found to exhibit temperature-independent (Van Vleck) paramagnetism with values typical of those found for other rare-earth-metal, zirconium, niobium, and tantalum cluster halides.
- Steinwand, Sharon J.,Corbett, John D.
-
p. 7056 - 7067
(2008/10/09)
-
- COMPLEXES OF YTTRIUM AND LANTHANIDE BROMIDES WITH 4-N-(2'-HYDROXYBENZYLIDENE)AMINOANTIPYRINEY
-
Ten new complexes of bromides of yttrium and lanthanides with 4-N-(2'-hydroxybenzylidene)aminoantipyrine (HBAAP) having the formula [Ln(HBAAP)2Br2]Br, where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho and Er have been prepared and characterized. Molar conductance studies indicate 1:1 electrolytic behaviour for these complexes. Their infrared spectra show that HBAAP acts as a neutral tridentate ligand coordinatin throuhg the carbonyl oxzgen, azomethine nitrogen and phenolic oxygen. Electronic spectra showthe week covalent character in the metal-ligand bond. Thermogravimetric studies indicate that these complexes are stable up to about 170.degree .C and undergo decomposition in two stages forming the respective metal bromides as the final products.
- Joseph, M.,Nair, M. K. M.,Radhakrishnan, P. K.
-
p. 1331 - 1344
(2008/10/09)
-
- Thermodynamics of lanthanide elements, IV. Molar enthalpies of formation of Y3+(aq), YCl3(cr), YBr3(cr), and YI3(cr)
-
Enthalpies of solution of high-purity yttrium metal and of yttrium trichloride, tribromide, and triiodide in hydrochloric acid of various molalities lead to the following standard molar enthalpies of formation ΔfH0m/(kJ *
- Xiang-Yun, Wang,Zhu, Jin Tian,Goudiakas, J.,Fuger, J.
-
p. 1195 - 1202
(2007/10/02)
-
