Ternary Indides Eu2Pd2In and Eu2Pt2In

The indides Eu₂Pd₂In and Eu₂Pt₂In were synthesized from the elements in sealed tantalum tubes in an induction furnace. The samples were characterized by powder X‐ray diffraction. The structures were refined on the basis of single‐crystal X‐ray diffractometer data: HT‐Pr₂Co₂Al type, C2/c, a = 1035.7(2), b = 592.9(1), c = 823.6(2) pm, β = 104.26(1) °, wR2 = 0.026, 1075 F² values, 25 variables for Eu₂Pd₂In and a = 1017.2(2), b = 588.7(1), c = 826.5(1) pm, β = 103.76(1) °, wR2 = 0.062, 706 F² values, 25 variables for Eu₂Pt₂In. The indium atoms have four platinum (palladium) neighbors in strongly distorted tetrahedral coordination at Pt–In and Pd–In distances ranging from 273 to 275 pm. These InPd_4/2 and InPt_4/2 units are condensed via common edges to infinite InPd₂ and InPt₂ chains, which are surrounded by the europium atoms. The chains form the motif of hexagonal rod packing.     

Rare Earth-Rich Indides <Emphasis Type="Italic">RE</Emphasis><Subscript>5</Subscript>Pt<Subscript>2</Subscript>In<Subscript>4</Subscript> (<Emphasis Type="Italic">RE</Emphasis> = Sc,Y, La–Nd,Sm, Gd–Tm,Lu)

Summary. The isotypic indides RE ₅Pt₂In₄ (RE = Sc, Y, La–Nd, Sm, Gd–Tm, Lu) were synthesized by arc-melting of the elements and subsequent annealing. They were investigated via X-ray powder diffraction. Small single crystals of Gd₅Pt₂In₄ were grown via slow cooling and the structure was refined from X-ray single crystal diffractometer data: Pbam, a = 1819.2(9), b = 803.2(3), c = 367.6(2) pm, wR ² = 0.089, 893 F ² values and 36 parameters. The structure is an intergrowth variant of distorted trigonal and square prismatic slabs of compositions GdPt and GdIn. Together the platinum and indium atoms build up one-dimensional [Pt₂In₄] networks (292–333 pm Pt–In and 328–368 pm In–In) in an AA stacking sequence along the c axis. The gadolinium atoms fill distorted square and pentagonal prismatic cages between these networks with strong bonding to the platinum atoms.     

Quaternary indides LaTIn3Mg (T = Rh and Ir) and CeIrIn3Mg with LaCoAl4 type structure

The quaternary indides LaTIn₃Mg (T = Rh and Ir) and CeIrIn₃Mg were prepared from the elements in sealed tantalum ampoules in an induction furnace. The samples were characterized by X-ray powder and single crystal data: LaCoAl₄ type, Pmma, Z = 2, a = 830.5(1), b = 436.1(1), c = 745.1(1) pm, wR2 = 0.038, 467 F ² values for LaRhIn_3.075Mg_0.925, a = 832.9(1), b = 436.5(1), c = 746.9(1) pm, wR2 = 0.077, 471 F ² values for LaIrIn_3.091Mg_0.909, and a = 832.2(1), b = 434.1(1), c = 743.9(1) pm, wR2 = 0.066, 465 F ² values for CeIrIn_3.07Mg_0.93 with 25 variables for each refinement. The transition metal, indium, and magnesium atoms build up three-dimensional [TIn₃Mg] networks which leave pentagonal prismatic voids for the lanthanum and cerium atoms. The transition metal atoms have tricapped trigonal prismatic coordination and the magnesium atoms fill distorted square prisms. All three crystals revealed a small degree of Mg/In mixing on the latter site.     

Das Indid‐Hydrid Ba9[In]4[H]: Synthese,Kristallstruktur, NMR‐Spektroskopie,Chemische Bindung

The new indide hydride Ba₉[In]₄[H] was synthesized from the elements in stoichiometric proportions using the inherent hydrogen content of commercial elemental barium as hydrogen source. Its structure, constituting a new type, was determined using single‐crystal X‐ray data (tetragonal, space group I4/m, a = 1397.3(2), c = 591.8(1) pm, Z = 2) in sufficient quality (R1 = 0.0261) to allow identification and location of the hydride ion as well as the refinement of its thermal parameter. The crystal structure of Ba₉[In]₄[H] exhibits isolated indium atoms, which are coordinated by 10 barium cations in a cubicosahedral arrangement. The hydride anions are octahedrally surrounded by six Ba²⁺ cations. According to [HBa₄Ba_2/2] these octahedra are connected by opposite corners to form chains running along the c axis. The presence of the hydride ion was determined by solid state NMR spectroscopy, where the chemical shift of the ¹H‐MAS‐NMR signal of–9.0 ppm nicely corresponds to the values in BaH₂ and other metallid hydrides. Like in other binary alkaline‐earth indides, the band structure calculated in the frame of the FP‐LAPW methods shows a pseudo band gap slightly above the Fermi level, associated with the electron precise valence electron count after Zintl (isolated In^5–). The title compound was compared to other hydrides and indides both according to the structural as well as the bonding features.     

Transition Metal Centered Trigonal Prisms as Building Units in Various Rare Earth–Transition Metal-Indides

Summary. The rare earth–transition metal-indides GdPdIn, ErPdIn, YbPdIn, YPtIn, TmPtIn, Dy₄Pd₁₀In₂₁, PrPt₂In₂, and Tb₂Pt₇In₁₆ were prepared by arc-melting of the elements or by induction melting of the elements in sealed tantalum tubes in a water-cooled sample chamber of a high-frequency furnace. Single crystals of Dy₄Pd₁₀In₂₁ and Tb₂Pt₇In₁₆ were grown through special annealing procedures. The indides were investigated via X-ray powder diffraction and all structures were refined from X-ray single crystal diffractometer data: ZrNiAl type, , a = 767.8(3), c = 390.7(2) pm, wR2 = 0.0722, 356 F² values for GdPdIn; a = 766.7(3), c = 376.7(1) pm, wR2 = 0.0433, 348 F² values for ErPdIn; a = 757.2(2), c = 393.59(8) pm, wR2 = 0.0388, 434 F² values for YbPdIn; a = 758.2(2), c = 384.95(8) pm, wR2 = 0.0643, 353 F² values for YPtIn; and a = 753.4(1), c = 376.71(4) pm, wR2 = 0.0844, 310 F² values for TmPtIn, with 14 variable parameters per refinement. Dy₄Pd₁₀In₂₁ crystallizes with the monoclinic Ho₄Ni₁₀Ga₂₁ structure: C2/m, a = 2284.5(8), b = 441.0(2), c = 1931.4(7) pm, β = 132.74(2)°, wR2 = 0.0419, 1690 F² values, 112 variable parameters. PrPt₂In₂ adopts the CePt₂In₂ type: P2₁/m, a = 1013.2(3), b = 447.2(3), c = 1019.5(3) pm, β = 116.69(2)°, wR2 = 0.0607, 1259 F² values, 63 variable parameters. Tb₂Pt₇In₁₆ is the second representative of the orthorhombic Dy₂Pt₇In₁₆ type: Cmmm, a = 1211.6(2), b = 1997.1(4), c = 440.52(9) pm, wR2 = 0.0787, 1341 F² values, 45 variable parameters. The common structural motif of the four different structure types are transition metal centered trigonal prisms formed by the rare earth metal and indium atoms. These prisms are condensed via common corners or via In–In bonds. The crystal chemistry of the four different structure types is discussed.     

Zr<Subscript>5</Subscript>Ir<Subscript>2</Subscript>In<Subscript>4</Subscript> – A Superstructure of the Lu<Subscript>5</Subscript>Ni<Subscript>2</Subscript>In<Subscript>4</Subscript> Type

Summary. Zr₅Ir₂In₄ was synthesized by reaction of the elements in a glassy carbon crucible in a water-cooled sample chamber of an induction furnace. The sample was characterized by X-ray diffraction on both powder and single crystals. Zr₅Ir₂In₄ crystallizes with a pronounced Lu₅Ni₂In₄ type subcell, space group Pbam, a=1739.5(6), b=766.3(2), c=338.9(2) pm. Weak additional reflections force a doubling of the subcell c axis. The superstructure of Zr₅Ir₂In₄ is of a new type: Pnma, a=1739.5(6), b=677.8(2), c=766.3(2) pm, wR2=0.0529, 1592 F² values, and 60 variable parameters. The group-subgroup scheme for the klassengleiche symmetry reduction is presented. The formation of the superstructure is most likely due to a puckering effect (size of the iridium atoms). The crystal chemistry of Zr₅Ir₂In₄ is briefly discussed.     

Rare earth metal-rich indides RE 4IrIn ( RE = Gd–Er), RE 4IrInO0.25 ( RE = Gd, Er), and RE 4 T In1– x Mg x ( RE = Y, Gd; T = Rh, Ir)

The rare earth-transition metal-indides RE ₄IrIn (RE = Gd–Er) and the solid solutions RE ₄ TIn_1–x Mg _x (RE = Y, Gd; T = Rh, Ir) were prepared by arc-melting of the elements and subsequent annealing. The rare earth sesquioxides were used as oxygen source for the suboxides RE ₄IrInO_0.25 (RE = Gd, Er). Single crystals of the indides were grown via slowly cooling of the samples and they were investigated via X-ray powder diffraction and single crystal diffractometer data: Gd₄RhIn type, F 3m, a = 1372.3(6) pm for Gd₄IrIn, a = 1365.3(6) pm for Tb₄IrIn, a = 1356.7(4) pm for Dy₄IrIn, a = 1353.9(4) pm for Ho₄IrIn, a = 1344.1(4) pm for Er₄IrIn, a = 1370.3(5) pm for Y₄RhIn_0.54Mg_0.46, a = 1375.6(5) pm for Gd₄IrIn_0.55Mg_0.45, a = 1373.0(3) pm for Gd₄IrInO_0.25, and a = 1345.1(4) pm for Er₄IrInO_0.25. The rhodium and iridium atoms have a trigonal prismatic rare earth coordination. Condensation of the RhRE ₆ and IrRE ₆ prisms leads to three-dimensional networks which leave voids that are filled by regular In₄ or mixed In_4–x Mg _x tetrahedra. The indium (magnesium) atoms have twelve nearest neighbors (3In(Mg) + 9RE) in icosahedral coordination. The rare earth atoms build up a three-dimensional, adamantane-like network of condensed, edge and face-sharing octahedra. For Gd₄IrInO_0.25 and Er₄IrInO_0.25 the RE1₆ octahedra are filled with oxygen. The crystal chemical peculiarities of these rare earth rich compounds are discussed. Correspondence: Rainer P?ttgen, Institut für Anorganische und Analytische Chemie, Westf?lische Wilhelms-Universit?t Münster, Germany.     

EuAuGe Type Indides RAgIn (R = Ca,Sr, La,Eu)

The equiatomic intermetallic phases CaAgIn [a = 482.75(7), b = 750.0(1), c = 835.5(1) pm], SrAgIn [a = 495.86(5), b = 794.71(9), c = 851.89(9) pm], LaAgIn [a = 489.99(5), b = 767.93(9), c = 837.53(9) pm], and EuAgIn [a = 493.02(7), b = 781.6(1), c = 844.2(1) pm] were synthesized from the elements in sealed niobum containers. They crystallize with the EuAuGe type structure, space group Imm2. The four structures were refined from single‐crystal X‐ray data. The silver and indium atoms build up orthorhombically distorted, puckered Ag₃In₃ hexagons, which are stacked in AA′ sequence, leading to direct Ag–Ag and In–In interlayer bonding (e.g. 303 and 304 pm in CaAgIn). Temperature dependent magnetic susceptibility measurements show a magnetic moment of 7.40(1) μ_B per europium atom. EuAgIn orders antiferromagnetically at 5.7(5) K. The divalent nature of europium is also evident from ¹⁵¹Eu Mössbauer spectra: δ = –10.50(1) mm · s^–1 at 78 K.     

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).     

Copper-indium ordering in RECu6In6 (RE=Y, Ce, Pr, Nd, Gd, Tb, Dy)

The rare earth metal-copper-indides RECu₆In₆ (RE=Y, Ce, Pr, Nd, Gd, Tb, Dy) were synthesized from the elements by arc-melting. Well-crystallized samples were obtained by slowly cooling the melted buttons from 1320 to 670 K in sealed silica tubes in a muffle furnace. They were investigated by X-ray diffraction on powders and single crystals: ThMn₁₂ type, space group I4/mmm, Z=2, a=916.3(2), c=535.8(2) pm, wR₂=0.063, 216 F² values, 15 variables for YCu₆In₆, a=926.5(4), c=543.5(3) pm, wR₂=0.064, 314 F² values, 15 variables for CeCu₆In₆, a=925.7(4), c=540.1(3) pm, wR₂=0.075, 219 F² values, 15 variables for PrCu₆In₆, a=923.1(4), c=540.3(3) pm, wR₂=0.071, 218 F² values, 15 variables for NdCu₆In₆, a=917.7(4), c=540.2(3) pm, wR₂=0.076, 207 F² values, 15 variables for GdCu₆In₆, a=917.0(5), c=540.5(4) pm, wR₂=0.062, 215 F² values, 15 variables for TbCu₆In₆, a=915.2(8), c=540.7(7) pm, wR₂=0.108, 218 F² values, 15 variables for DyCu₆In₆. The structures have been refined with a split position (50% Cu+50% In) for the 8j site. They can be explained by a tetragonal body-centered packing of CN 20 polyhedra (10Cu+10In) around the rare earth atoms. The ordering models of the copper and indium atoms and the limitations/resolution of X-ray diffraction for this topic are discussed.