Ternary system Er–Ni–In at T=870 K

Isothermal section of the Er–Ni–In system at T=870 K was constructed by means of X-ray powder diffraction and EDX-analyses. Nine ternary compounds, namely ErNi₉In₂ (YNi₉In₂-type), Er_1−1.22Ni₄In_1−0.78 (MgCu₄Sn-type), Er₁₀Ni_9.07In₂₀ (Ho₁₀Ni₉In₂₀-type), ErNi_1−0.60In_1−1.40 (ZrNiAl-type), Er₂Ni₂In (Mn₂AlB₂-type), Er₂Ni_1.78In (Mo₂FeB₂-type), Er₅Ni₂In₄ (Lu₅Ni₂In₄-type), Er₅Ni₂In (Mo₅SiB₂-type), and Er_13.53Ni_3.14In_3.33 (Lu₁₄Co₂In₃-type), exist in the Er–Ni–In system at this temperature. The substitution of Ni for In was observed for ErNi_1−0.60In_1−1.40 and In for Er in the case of related compounds ErNi₂ and ErNi₄In. Er can enter NiIn (CoSn-type) leading to including-substitution type of compound Er_0−0.12NiIn_1−0.89. Basic magnetic properties of the Er_0.04NiIn_0.97, ErNi₂, Er_0.9Ni₂In_0.1, and ErNi₄In phases were inspected. Electrical-resistivity studies were performed on the ErNiIn, ErNi_0.9In_1.1, and ErNi₄In phases.     

Variations of the FeGa3 Structure Type in the Systems CoIn3−xZnx and CoGa3−xZnx

We present an investigation of the quasibinary systems CoIn_3−xZn_x and CoGa_3−xZn_x which were structurally characterized by X-ray diffraction experiments and, in the case of CoGa_3−xZn_x, additionally by neutron powder diffraction experiments. The limiting compositions were found to be x=0.81(2) and x=0.73(2) for CoIn_3−xZn_x and CoGa_3−xZn_x, respectively. The isotypic binary compounds CoIn₃ and CoGa₃ crystallize with the FeGa₃ structure type (tetragonal, space group P4₂/mnm, Z=4) in which the p-block atoms form an array of columns of centered cubes defined by two different crystallographic sites. The substitution of In or Ga by Zn takes place in an ordered fashion and produces “colored” variants of the FeGa₃ parent structure: In both systems Zn enters exclusively the position corresponding to the cube centers. Additionally, in CoIn_3−xZn_x this position is substituted in such a way that for a composition CoIn_2.5Zn_0.5, columns of Zn- and In-filled In₈ cubes along the c axis alternate. The latter substitution pattern is accompanied by a symmetry lowering of the parent FeGa₃ structure: The structure of CoIn_3−xZn_x is described by the space group P4₂/m in which the cube center position is split into two separate sites. By performing first-principles electronic structure calculations we investigated the general bonding situation of the compounds CoIn₃ and CoGa₃ and the particular electronic effect when incorporating Zn. With respect to the density of states of the binary compounds the exchange of Ga or In by Zn virtually affects only the electronic states just below the Fermi level. On increasing Zn concentration a dip is created in the density of states which approximately coincides with the location of the Fermi level for an electron count corresponding to limiting composition of the two systems.     

Rare earth metal-rich indides RE14Rh3−xIn3 (RE=Y, Dy, Ho, Er, Tm, Lu)

The rare earth (RE) metal-rich indides RE₁₄Rh_3-xIn₃ (RE=Y, Dy, Ho, Er, Tm, Lu) can be synthesized from the elements by arc-melting or induction melting in tantalum crucibles. They were investigated by X-ray diffraction on powders and single crystals: Lu₁₄Co₃In₃ type, space group P4₂/nmc, Z=4, a=961.7(1), c=2335.5(5) pm, wR2=0.052, 2047 F² values, 62 variables for Y₁₄Rh₃In₃, a=956.8(1), c=2322.5(5) pm, wR2=0.068, 1730 F² values, 63 variables for Dy₁₄Rh_2.89(1)In₃, a=952.4(1), c=2309.2(5) pm, wR2=0.041, 1706 F² values, 63 variables for Ho₁₄Rh_2.85(1)In₃, a=948.6(1), c=2302.8(5) pm, wR2=0.053, 1977 F² values, 63 variables for Er₁₄Rh_2.86(1)In₃, a=943.8(1), c=2291.5(5) pm, wR2=0.065, 1936 F² values, 63 variables for Tm₁₄Rh_2.89(1)In₃, and a=937.8(1), c=2276.5(5) pm, wR2=0.050, 1637 F² values, 63 variables for Lu₁₄Rh_2.74(1)In₃. Except Yb₁₄Rh₃In₃, the 8g Rh1 sites show small defects. Striking structural motifs are rhodium-centered trigonal prisms formed by the RE atoms with comparatively short Rh-RE distances (271-284 pm in Y₁₄Rh₃In₃). These prisms are condensed via common corners and edges building two-dimensional polyhedral units. Both crystallographically independent indium sites show distorted icosahedral coordination. The icosahedra around In2 are interpenetrating, leading to In2-In2 pairs (309 pm in Y₁₄Rh₃In₃).     

Syntheses and Structure of Er6Co2.19(1)In0.81(1)

Summary. The erbium–cobalt–indide Er₆Co_2.19(1)In_0.81(1) was prepared by arc-melting of the pure elements. Single crystals were obtained through a special annealing procedure. Er₆Co_2.19(1)In_0.81(1) crystallizes with the orthorhombic Ho₆Co₂Ga structure: Immm, a = 934.3(1), b = 936.4(1), c = 985.4(1) pm, wR2 = 0.0557, 892 F ² values, and 35 variable parameters. The structure contains two gama;crystallographically independent Co₂ dumb-bells at Co–Co distances of 223 and 236 pm, respectively. Further structural motifs are distorted octahedral Er₆ clusters (336–401 pm Er–Er) which are condensed to a three-dimensional network via all corners. The In2 atoms have a distorted icosahedral erbium coordination (329–355 pm In2–Er). These icosahedra show an orthorhombically distorted bcc packing.     

The crystal structure of Sm4Ni11In20 and its relation to other indium-rich compounds

Polycrystalline Sm₄Ni₁₁In₂₀ was obtained by arc-melting of metal ingots. A subsequent high temperature treatment was used for single crystal growth. The Sm₄Ni₁₁In₂₀ crystal structure (U₄Ni₁₁Ga₂₀ type; C2/m, a = 22.5457(3) Å, b = 4.34929(5) Å, c = 16.5479(2) Å, β = 124.592(2)°, R1 = 0.0358, wR2 = 0.0934) was determined by single crystal synchrotron radiation X-ray diffraction from 2014 independent reflections with I > 2σ(I). Sm₄Ni₁₁In₂₀ extends the R ₄Ni₁₁In₂₀ (R = Y, Gd, Tb, Dy, Ho) series of phases. The R ₄Ni₁₁In₂₀ and RNi₃In₆ (LaNi₃In₆ type; R = La, Ce, Pr, Nd, Eu) series have similar compositions. Their structures share similar fragments; in particular the rare earth atom coordination polyhedra are pentagonal prisms with additional atoms.      

The crystal structure of Ho<Subscript>4</Subscript>Ni<Subscript>11</Subscript>In<Subscript>20</Subscript>

The polycrystalline Ho₄Ni₁₁In₂₀ was obtained by arc-melting of the elements. The subsequent high temperature procedure was used for single crystal growth. Crystal structure of the compound was investigated by X-ray single crystal method: U₄Ni₁₁Ga₂₀ type, C 2/m, a = 22.4528(17), b = 4.2947(3), c = 16.5587(13) Å, β = 124.591(5)°, R1 = 0.0276, wR2 = 0.0493 for 1989 independent reflections with [I>2σ(I)].The structure is composed of three-dimensional network from Ni and In atoms in which Ho atoms fill distorted pentagonal channels. Open image in new window     

Novel Cu and Cu2In/aluminosilicate type catalysts for the reduction of biomass-derived volatile fatty acids to alcohols

This work relates to the consecutive reduction of short chain carboxylic acids (volatile fatty acids, VFAs) to alcohols as main products. Acetic acid (AA) was used as a reactant to model the VFAs that can be produced by either thermochemical or biological biomass degradation. The amorphised zeolite supported copper catalysts (Cu/SiAl), especially the In-modified CuIn/SiAl catalysts, showed high hydroconversion activity and selectivity for alcohol, ester and aldehyde. Catalysts containing dispersed copper particles in amorphous aluminosilicate were obtained by dehydrating and H₂-reducing Cu-forms of low-silica synthetic zeolites (A, X, P). The activity of the highly destructed Cu-aluminosilicates was found to depend on the structure of the zeolite precursor. The formation of ethyl acetate could be suppressed by adding water to the AA feed and by modifying the catalyst, e.g. by In₂O₃ additive. In the catalysts modified by In₂O₃ additive formation of copper-indium alloy phase (Cu₂In intermetallic compound) was detected resulting in a different selectivity than the one recorded for the Cu/SiAl.      

Syntheses, structural determination, and binding studies of mononuclear nine-coordinate (EnH2)1.5[HoIII(Ttha)] · 4.5H2O and two dimensional unlimited network (EnH2)[HoIII(Egta)(H2O)]2 · 6H2O

Two novel complexes, (EnH₂)_1.5[Ho^III(Ttha)] · 4.5H₂O (I) (En = ethylenediamine and H₆Ttha = triethylenetetramine-N,N,N′,N″,N?,N?-hexaacetic acid) and (EnH₂)[Ho^III(Egta)(H₂O)]₂ · 6H₂O (II) (H₄Egta = ethyleneglycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid), were synthesized and their crystal structures were determined by single crystal X-ray diffraction techniques. Complex I has a nine-coordinate mononuclear structure with distorted tricapped trigonal prismatic conformation and crystallizes in the monoclinic crystal system with P2/n space group. The crystal data are as follows: a = 17.7541(18), b = 9.6810(10), c = 22.166(2) Å, β = 118.913(2)°, and V = 3335.0(6) ų. Complex II has a mononuclear nine-coordinate structure with pseudo-monocapped square antiprismatic conformation and crystallizes in the monoclinic crystal system with P2₁/n space group. The crystal data are as follows: a = 12.978(8), b = 12.685(8), c = 14.905(9) Å, β = 105.333(7)°, and V = 2366(2) ų. In I, there are two types of EnH ₂ ²⁺ anions. They connect to [Ho^III(Ttha)]^3? by hydrogen bonds leading to the formation of 3D pore structure along z axis. In II, EnH ₂ ²⁺ cation connects three adjacent [Ho^III(Egta)(H₂O)]^? complex anions through hydrogen bonds, these hydrogen bonds lead to the formation of 2D network structure in [101] plane. The results showed that ligand structures play a crucial role in crystal and molecular structure of their complexes. In addition, the protonated (EnH ₂ ²⁺ ) cations conjugating to [Ho^III(Ttha)]^3? and [Ho^III(Egta)(H₂O)]^? complex anions are reviewed, which act as an important beginning for study of Ho(III) complexes conjugating with other various amino and heterocyclic biomolecule.     

Thermal analysis of rare-earth metal(III) hexa(isothiocyanato)chromate(III) complexes with ɛ-caprolactam

Thermal decomposition of the complexes [LnL₈][Cr(NCS)₆] (Ln = La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Tm³⁺, Yb³⁺, Lu³⁺; L = ɛ-C₆H₁₁NO) in air and in inert atmosphere was studied by thermogravimetry, X-ray phase analysis, IR spectroscopy, and mass spectrometry. The compositions of gaseous and solid thermolysis products were established. A reversible thermochromic effect was found on heating to 200–210°C.     

Stability prediction of Cu2+, Ni2+ and Zn2+ N-salicylidene-aminoacidato complexes by models based on connectivity index 3 χ v

This paper presents models for the estimation of stability constants (K ₁ and β ₂) of nickel(II), copper(II) and zinc(II) mono- and bis-complexes with 5 Schiff bases (salicylideneglycine, salicylidenealanine, salicylideneserine, salicylidenephenylalanine, and salicylidenetyrosine). The models were based on the molecular-graph theory and valence molecular connectivity index of the 3^rd order, ³χ ^v , derived from it. Univariate linear models were developed for each metal separately, while in the common models for two and three metals, the indicator variable, In, was introduced. The standard error of models for the log K ₁ constant was less than 0.12, while for log β ₂ models, the S.E. did not exceed 0.14.      

Chemischer Transport fester Lösungen: Der chemische Transport von Mischkristallen im System Co3O4 /CoGa2O4

Chemical Transport of Solid Solutions: Transport Phenomena in the Co₃O₄ /CoGa₂O₄ System Chemical transport reactions are a suitable pathway to the preparation of mixed spinels Co(Ga, Co)₂O₄ in the Co₃O₄/CoGa₂O₄ system. Solid solutions with specific Co^III/Ga^III ratios are accessible via variation of the source material compositions, because Co₃O₄ and CoGa₂O₄ are completely miscible. Electron microprobe analyses indicate the beginning of a zoning process in the crystals deposited. Experiments are consistent with thermodynamic calculations.     

New rare earth metal-rich indides RE14Ni3In3 (RE=Sc, Y, Gd-Tm, Lu)—synthesis and crystal chemistry

The rare earth-nickel-indides RE₁₄Ni₃In₃ (RE=Sc, Y, Gd-Tm, Lu) were synthesized from the elements by arc-melting and subsequent annealing. The compounds were investigated on the basis of X-ray powder and single crystal data: Lu₁₄Co₂In₃ type, P4₂/nmc, Z=4, a=888.1(1), c=2134.7(4), wR2=0.0653, 1381 F² values, 63 variables for Sc_13.89Ni_3.66In_2.45; a=961.2(1), c=2316.2(5), wR2=0.0633, 1741 F² values, 64 variables for Y_13.84Ni_3.19In_2.97; a=965.3(1), c=2330.5(5), wR2=0.0620, 1765 F² values, 63 variables for Gd₁₄Ni_3.29In_2.71; a=956.8(1), c=2298.4(5), wR2=0.0829, 1707 F² values, 64 variables for Tb_13.82Ni_3.36In_2.82; a=951.7(1), c=2289.0(5), wR2=0.0838, 1794 F² values, 64 variables for Dy_13.60Ni_3.34In_3.06; a=948.53(7), c=2270.6(1), wR2=0.1137, 1191 F² values, 64 variables for Ho_13.35Ni_3.17In_3.48; a=943.5(1), c=2269.1(5), wR2=0.0552, 1646 F² values, 64 variables for Er_13.53Ni_3.14In_3.33; a=938.42(7), c=2250.8(1), wR2=0.1051, 1611 F² values, 64 variables for Tm_13.47Ni_3.28In_3.25; a=937.3(1), c=2249.6(5), wR2=0.0692, 1604 F² values, 64 variables for Tm_13.80Ni_3.49In_2.71; and a=933.4(1), c=2263.0(5), wR2=0.0709, 1603 F² values, 64 variables for Lu_13.94Ni_3.07In_2.99. The RE₁₄Ni₃In₃ indides show significant Ni/In mixing on the 4c In1 site. Except the gadolinium compound, the RE₁₄Ni₃In₃ intermetallics also reveal RE/In mixing on the 4c RE1 site, leading to the refined compositions. Due to the high rare earth metal content, the seven crystallographically independent RE sites have between 9 and 10 nearest RE neighbors. The RE₁₄Ni₃In₃ structures can be described as a complex intergrowth of rare earth-based polyhedra. Both nickel sites have a distorted trigonal-prismatic rare earth coordination. An interesting feature is the In2-In2 dumb-bell at an In2-In2 distance of 304 pm (for Gd₁₄Ni_3.29In_2.71). The crystal chemical peculiarities of the RE₁₄Ni₃In₃ indides are briefly discussed.     

DNA Intercalating Near-Infrared Luminescent Lanthanide Complexes Containing Dipyrido[3,2-a:2′,3′-c]phenazine (dppz) Ligands: Synthesis,Crystal Structures,Stability, Luminescence Properties and CT-DNA Interaction

In order to create near-infrared (NIR) luminescent lanthanide complexes suitable for DNA-interaction, novel lanthanide dppz complexes with general formula [Ln(NO₃)₃(dppz)₂] (Ln = Nd³⁺, Er³⁺ and Yb³⁺; dppz = dipyrido[3,2-a:2′,3′-c]phenazine) were synthesized, characterized and their luminescence properties were investigated. In addition, analogous compounds with other lanthanide ions (Ln = Ce³⁺, Pr³⁺, Sm³⁺, Eu³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Tm³⁺, Lu³⁺) were prepared. All complexes were characterized by IR spectroscopy and elemental analysis. Single-crystal X-ray diffraction analysis of the complexes (Ln = La³⁺, Ce³⁺, Pr³⁺, Nd³⁺, Eu³⁺, Er³⁺, Yb³⁺, Lu³⁺) showed that the lanthanide’s first coordination sphere can be described as a bicapped dodecahedron, made up of two bidentate dppz ligands and three bidentate-coordinating nitrate anions. Efficient energy transfer was observed from the dppz ligand to the lanthanide ion (Nd³⁺, Er³⁺ and Yb³⁺), while relatively high luminescence lifetimes were detected for these complexes. In their excitation spectra, the maximum of the strong broad band is located at around 385 nm and this wavelength was further used for excitation of the chosen complexes. In their emission spectra, the following characteristic NIR emission peaks were observed: for a) Nd³⁺: ⁴F_3/2 → ⁴I_9/2 (870.8 nm), ⁴F_3/2 → ⁴I_11/2 (1052.7 nm) and ⁴F_3/2 → ⁴I_13/2 (1334.5 nm); b) Er³⁺: ⁴I_13/2 → ⁴I_15/2 (1529.0 nm) c) Yb³⁺: ²F_5/2 → ²F_7/2 (977.6 nm). While its low triplet energy level is ideally suited for efficient sensitization of Nd³⁺ and Er³⁺, the dppz ligand is considered not favorable as a sensitizer for most of the visible emitting lanthanide ions, due to its low-lying triplet level, which is too low for the accepting levels of most visible emitting lanthanides. Furthermore, the DNA intercalation ability of the [Nd(NO₃)₃(dppz)₂] complex with calf thymus DNA (CT-DNA) was confirmed using fluorescence spectroscopy.     

In situ growth of Co3O4 nano-dodecahedeons on In2O3 hexagonal prisms for toluene catalytic combustion

In this paper, in situ growth of Co₃O₄ nano-dodecahedra on In₂O₃ hexagonal prisms were synthesized via pyrolysis of ZIF-67/MIL-68. Interestingly, the amount of Co₃O₄ dodecahedra on In₂O₃ hexagonal prisms was regularly regulated and controlled. In detail, four Co₃O₄/In₂O₃ catalysts with various Co/In molar ratio were prepared, including Co₄In₁ (Co/In molar ratio was 4:1), Co₂In₁ (Co/In molar ratio was 2:1), Co₁In₁ (Co/In molar ratio was 1:1), Co_0.5In₁ (Co/In molar ratio was 0.5:1). The catalytic performance of Co₃O₄/In₂O₃ catalysts was systematically investigated for toluene combustion. It could be noted that the Co₂In₁ sample exhibited the superior catalytic performance, and the temperatures for 90% toluene conversion (T₉₀) was 182 °C. Furthermore, the toluene conversion of Co₂In₁ sample had no significant decrease at 178 °C for 15 h, indicating that it presented superior stability for toluene oxidation reaction. Through various characterizations, it was verified that the Co/In molar ratio of Co₃O₄/In₂O₃ catalyst could obviously alter the surface atomic ratio of Co³⁺/(Co³⁺ + Co²⁺), BET surface area, the number of surface adsorbed oxygen, the interaction between In₂O₃ and Co₃O₄ of CoInO_x catalysts and so on. The lots of surface adsorbed oxygen, strong interaction between In₂O₃ and Co₃O₄ would promote the catalytic oxidation of toluene. Especially, we discovered that the catalytic activity of Co₃O₄/In₂O₃ was obviously improved with the increase of Co³⁺/(Co³⁺ + Co²⁺) surface atomic ratio.     

Co6H8(PiPr3)6: A Cobalt Octahedron with Face‐Capping Hydrides

A square‐planar Co₄ amide cluster, Co₄{N(SiMe₃)₂}₄ ( 2 ), and an octahedral Co₆ hydride cluster, Co₆H₈(PⁱPr₃)₆ ( 4 ), were obtained from metathesis‐type amide to hydride exchange reactions of a Co^II amide complex with pinacolborane (HBpin) in the absence/presence of PⁱPr₃. The crystal structure of 4 revealed face‐capping hydrides on each triangular [Co₃] face, while the formal Co^II₂Co^I₄ oxidation state of 4 indicated a reduction of the cobalt centers during the assembly process. Cluster 4 catalyzes the hydrosilylation of 2‐cyclohexen‐1‐one favoring the conjugate reduction. Generation of the catalytically reactive Co cluster species was indicated by a trapping experiment with a chiral chelating agent.     

Syntheses, crystal structures and optical spectroscopy of Ln2(SO4)3·8H2O (Ln=Ho, Tm) and Pr2(SO4)3·4H2O

The lanthanide sulphate octahydrates Ln₂(SO₄)₃·8H₂O (Ln=Ho, Tm) and the respective tetrahydrate Pr₂(SO₄)₃·4H₂O were obtained by evaporation of aqueous reaction mixtures of trivalent rare earth oxides and sulphuric acid at 300 K. Ln₂(SO₄)₃·8H₂O (Ln=Ho, Tm) crystallise in space group C2/c (Z=4, a_Ho=13.4421(4) Å, b_Ho=6.6745(2) Å, c_Ho=18.1642(5) Å, β_Ho=102.006(1) Å³ and a_Tm=13.4118(14) Å, b_Tm=6.6402(6) Å, c_Tm=18.1040(16) Å, β_Tm=101.980(8) Å³), Pr₂(SO₄)₃·4H₂O adopts space group P2₁/n (a=13.051(3) Å, b=7.2047(14) Å, c=13.316(3) Å, β=92.55(3) Å³). The vibrational and optical spectra of Ho₂(SO₄)₃·8H₂O and Pr₂(SO₄)₃·4H₂O are also reported.     

Synthesis of new (arylcarbonyloxy)aminopropanol derivatives and the determination of their physico-chemical properties

Eight hydrochlorides of 3-{2-[(2/4-fluorophenoxy)-ethylamino]}-2-hydroxypropyl-4-alkoxybenzoates and four hydrochlorides of 3-tert-butylamino-2-hydroxypropyl-4-butoxybenzoates were prepared as potential antagonists of the β₁-adrenergic receptor (beta-blockers). A multistep synthesis of these compounds is described as well as their detailed analytical characterization. The pharmacokinetic properties of these weak base compounds are significantly influenced by their acid-base dissociation constant, pK _a. The knowledge of this value is crucial for new drug development. This paper is aimed at developing a methodology that utilizes pH-dependent ¹H NMR spectroscopy for its routine analysis. The selected predicted physico-chemical parameters of the new (arylcarbonyloxy)aminopropanols (i.e., aryloxyaminopropanol derivatives) were compared with the model drugs esmolol and flestolol.      

Phase diagram of SrO-InO1.5-CoOx and a new compound Sr3In0.9Co1.1O6

Sr₃In_0.9Co_1.1O₆, isostructural to Ca₃Co₂O₆, is revealed by the study of the phase relations in the system SrO-InO_1.5-CoO_x (1000 °C). The structure of Sr₃In_0.9Co_1.1O₆ is refined by the combination of powder X-ray and neutron diffraction. Sr₃In_0.9Co_1.1O₆ crystallizes in a trigonal lattice with the cell parameters a=b=9.59438(3) Å, c=11.02172(4) Å with the space group R-3c. Its structure possesses 1D (In/Co)O₃ chains running along the c-axis constructed by alternating face-sharing CoO₆ octahedra and (In_0.9Co_0.1)O₆ trigonal prisms. The co-occupation of In³⁺ and Co³⁺ at the trigonal prismatic site is evidenced by elementary analysis and determined by the structure refinement. Sr₃In_0.9Co_1.1O₆ is paramagnetic, and the susceptibility is consistent with the occupation of Co³⁺ at 10% of the trigonal prismatic positions in a high spin state (HS, S=2). The HS Co³⁺ is well separated by diamagnetic CoO₆ octahedra and InO₆ trigonal prisms and shows a g factor of 2.0 in the magnetic measurements.     

Magneto-optic and luminescent properties of tellurite glass TeO<Subscript>2</Subscript>-ZnCl<Subscript>2</Subscript> doped with rare-earth elements

Tellurite glasses were synthesized on the basis of the binary system composed of 70 mol % TeO₂ and 30 mol % ZnCl₂ and doped with Nd³⁺, Pr³⁺, Tb³⁺, Er³⁺, Yb³⁺, Ho³⁺. The physicochemical, luminescent, and magneto-optic properties of these glasses were studied.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 8, 2004, pp. 1262–1265.Original Russian Text Copyright © 2004 by Grishin, Gurev, Intyushin, Elliev, Pavlova, Savikin.     

Crystallographic and structural characterization of heterometallic platinum compounds part IV: heterotetranuclear clusters

This review includes over two hundred heterotetranuclear platinum clusters. The clusters are of the compositions Pt₃M, Pt₃M₂, PtM₃, Pt′₂MM′, PtM₂M′ and PtMM′M”. There are twenty five different M atoms (transition and non-transition) as a partner(s) of platinum. The four metal atoms are found in a tetrahedral, planar-rhombohedral, butterfly, spited-triangular, cubane, eight — and oligo-membered rings and a unique structures. There is wide variety of the ligands from uni to- undecadentate, with the most common P and C donor sites. The shortest Pt-M (transition) versus Pt-M (non-transition) bond distances are 2.4833(8)Å (M=Pd) vs. 2.4365(5)Å (Ge). Several relationships between the various structural parameters were found and are discussed.