Comparative high-pressure study and chemical bonding analysis of Rh3Bi14 and isostructural Rh3Bi12Br2

The binary compound Rh₃Bi₁₄ was synthesized from the elements. The compound is isostructural with Rh₃Bi₁₂Br₂, crystallizes with the orthorhombic space group Fddd (no. 70) and lattice parameters a=6.8959(15) Å, b=17.379(3) Å, c=31.758(6) Å. The crystal structure consists of a three-dimensional (3D) framework of edge-sharing cubes and square antiprisms (RhBi_8/2). It is closely related to the intermetallic compound RhBi₄, in which two Y-like frameworks of antiprisms interpenetrate. In Rh₃Bi₁₄ and Rh₃Bi₁₂Br₂, additional bismuth and bromine anions, respectively, fill the channels of the 3D polyhedral framework formed by covalently bonded rhodium and bismuth atoms. High-pressure X-ray powder diffraction data from synchrotron measurements of Rh₃Bi₁₄ and Rh₃Bi₁₂Br₂ indicate a high stability of both compounds in the investigated range from ambient pressure to ca. 30 GPa at ambient temperature.     

Bi9Rh2Br3, Bi9Rh2I3 und Bi9Ir2I3 – Eine neue Strukturfamilie quasi‐eindimensionaler Metalle

Bi₉Rh₂Br₃, Bi₉Rh₂I₃, and Bi₉Ir₂I₃ – A New Structure Family of Quasi One‐dimensional Metals Bi₉Rh₂Br₃, Bi₉Rh₂I₃, and Bi₉Ir₂I₃ were synthesized from the elements using niobium bromides or iodides as auxiliaries to modify the partial pressures in the course of the reaction. X‐ray diffraction on single crystals showed that the compounds are not isomorphous. However they have a common structural principle: strands of condensed [MBi₈] polyhedra, which are separated by halide anions. The spatial arrangement of the [MBi_1/1Bi_7/2] strands differs with the combination of elements: In Bi₉Rh₂I₃ (monoclinic, P2₁/m (no. 11), a = 775.6(1), b = 1374.9(2), c = 901.1(2) pm, β = 109.29(2)°) all strands are oriented parallel to each other. Bi₉Rh₂Br₃ (monoclinic, P2₁/m (no. 11), a = 927.98(8), b = 1372.1(1), c = 1992.7(2) pm, β = 100.77(1)°) and Bi₉Ir₂I₃ (orthorhombic, Pnma (no. 62), a = 2677.5(5), b = 1394.2(2), c = 967.6(1) pm) are ordered polytypes with two orientations changing in alternating layers of characteristic widths. The experimental proof of metallic conductivity in Bi₉Ir₂I₃ supports the assumption of delocalised electrons inside the  [MBi_1/1Bi_7/2] strands. The magnetic susceptibility of Bi₉Rh₂Br₃ increases slowly with decreasing temperature and shows a local maximum at about 14 K.     

The Weak 3D Topological Insulator Bi12Rh3Sn3I9

Topological insulators (TIs) gained high interest due to their protected electronic surface states that allow dissipation-free electron and information transport. In consequence, TIs are recommended as materials for spintronics and quantum computing. Yet, the number of well-characterized TIs is rather limited. To contribute to this field of research, we focused on new bismuth-based subiodides and recently succeeded in synthesizing a new compound Bi₁₂Rh₃Sn₃I₉, which is structurally closely related to Bi₁₄Rh₃I₉ – a stable, layered material. In fact, Bi₁₄Rh₃I₉ is the first experimentally supported weak 3D TI. Both structures are composed of well-defined intermetallic layers of _∞²[(Bi₄Rh)₃I]²⁺ with topologically protected electronic edge-states. The fundamental difference between Bi₁₄Rh₃I₉ and Bi₁₂Rh₃Sn₃I₉ lies in the composition and the arrangement of the anionic spacer. While the intermetallic 2D TI layers in Bi₁₄Rh₃I₉ are isolated by _∞¹[Bi₂I₈]²⁻ chains, the isoelectronic substitution of bismuth(III) with tin(II) leads to _∞²[Sn₃I₈]²⁻ layers as anionic spacers. First transport experiments support the 2D character of this material class and revealed metallic conductivity.     

Bi24Ru3Br20: Ein pseudo-tetragonales Subbromid mit [RuBi6Br12]-Clustern und [Ru2Bi17Br4]-Gruppen

Bi₂₄Ru₃Br₂₀: A Pseudo-Tetragonal Structure with [RuBi₆Br₁₂] Clusters and [Ru₂Bi₁₇Br₄] Groups The melting reaction of Ru with Bi and BiBr yields black, lustrous, air insensitive crystals of the subbromide Bi₂₄Ru₃Br₂₀. The orthorhombic crystal structure (space group Pc2₁n, a = b = 1377.8(1) pm, c = 3222.3(4) pm, V = 6117.0 · 10⁶ pm³) deceives pseudo-symmetry with respect to the tetragonal space group P4/ncc leading to multiply twinned crystals. The structure can formally be subdivided in [RuBi₆Br₁₂] clusters, [Ru₂Bi₁₇Br₄] stacks, and [BiBr₄] groups.     

Bi12,86Ni4Br6 und Bi12,86Ni4I6: Subhalogenide mit intermetallischen und salzartigen Schichtpaketen in alternierender Abfolge

Bi_12.86Ni₄Br₆ and Bi_12.86Ni₄I₆: Subhalides with Alternating Intermetallic and Salt‐like Layers The reaction of bismuth and nickel with bromine or iodine at 730 K yields black, air insensitive, needle shaped crystals of the ternary subhalides Bi_12.86Ni₄X₆ (X = Br, I). The isotypic compounds crystallize in the orthorhombic space groups Immm with a = 405.69(6) pm, b = 874.00(8) pm, c = 3744.7(4) pm for X = Br, and a = 410.05(5) pm, b = 912.84(7) pm, c = 3826.7(3) pm for X = I. The crystal structures contain characteristic fragments of the intermetallic phase Bi₃Ni: chains consisting of face‐sharing mono‐capped trigonal prisms of bismuth atoms with a nickel atom in the center of each prism. The chains form corrugated layers which are separated by halogen atoms and oligomeric [Bi_nX_4n+2] units of varying length. The halogenobismutate(III) units consist of trans‐edge‐sharing [BiX₆] octahedra. They are disordered within the crystal structures. The non‐integer stoichiometric coefficients of Bi_12.86Ni₄X₆ are due to the metric adjustment between the ionic and intermetallic parts of the structure. Extended Hückel calculations indicate, that the partial oxidation of the intermetallic phase causes a strengthening of the chemical bonding within the Bi₃Ni chains. The subiodide Bi_12.86Ni₄I₆ is paramagnetic and shows ferromagnetic ordering below 25 K.     

Bi34Ir3Br37: Ein pseudosymmetrisches Subbromid aus Bi5+- und Bi62+-Polykationen sowie [IrBi6Br12]–- und [IrBi6Br13]2–-Clusteranionen

Bi₃₄Ir₃Br₃₇: A Pseudo-Symmetric Subbromide with Bi₅⁺ and Bi₆²⁺ Polycations, and [IrBi₆Br₁₂]^– and [IrBi₆Br₁₃]^2– Cluster Anions The melting reaction of Ir with Bi and BiBr₃ yields black, lustrous, air insensitive crystals of the subbromide Bi₃₄Ir₃Br₃₇. The triclinic crystal structure (space group P 1, a = b = 1303.4(2) pm, c = 1647.4(4) pm, α = β 90°, γ = 120°, V = 2423.7 × 10⁶ pm³) deceives pseudo symmetry with respect to the rhombohedral space group R 3, which results in multiply twinned crystals. The structure can formally be subdivided in four new types of ionic groups: (a) cuboctahedral [IrBi₆Br₁₂]^– clusters, (b) [IrBi₆Br₁₃]^2– clusters with an additional Br atom, (c) Bi₅⁺ square pyramids, and (d) distorted Bi₆²⁺ octahedra. The compound shows a range of homogeneity due to variable contributions of the different clusters.     

The Subbromide Bi5Br4 – On the Existence of a Hidden Phase

Black and irregularly shaped crystals of the bismuth-rich bromide Bi₅Br₄ were obtained as a by-product of the reaction of CsBr, Bi, and BiBr₃. X-ray diffraction on a single-crystal revealed its orthorhombic structure with the space group Pmmn (no. 59) and lattice parameters a = 1800.0(2) pm, b = 1476.1(1) pm, and c = 924.5(2) pm at 296 K. The structure is composed of Bi₈²⁺ and Bi₉⁵⁺ polycations and bromidobismuthate(III) anions according to the structured formula Bi₅Br₄ = Bi₂₀Br₁₆ = Bi₈²⁺Bi₉⁵⁺[BiBr₅]^2–[Bi₂Br₁₁]^5–. Bi₅Br₄ is the bismuth-richest among the bismuth subhalides containing isolated polycations. Extensive differential scanning calorimetry studies indicate that Bi₅Br₄ decomposes at 262 °C, i.e. one degree below the bismuth-rich eutectic at 263 °C. All attempts towards a rational synthesis yielded predominantly the neighboring phases BiBr and Bi₆Br₇.     

The crystal structure of eulytite Na3Bi5(PO4)6

The crystal structure of Na₃Bi₅(PO₄)₆ was solved using the single-crystal X-ray diffraction technique. The structural refinement has led to a reliability factor of R₁=0.0257 (wR₂=0.0533) for 428 independent reflections. This compound was found to crystallize in the cubic system (space group I4̄3d) with eulytite structure and the lattice parameters: a=10.097 (4) Å, V=1029.38 ų, Z=2, D_calc.=5.43 g cm⁻³ (D_exp.=5.32(5) g cm⁻³). The structure is characterized by the existence of one single general position (48a) for oxygen anions and two distinguished positions (16c) occupied by Na⁺ and Bi³⁺ cations, respectively. The site occupation factors are equal to 3/8 and 5/8 for sodium and bismuth, respectively. Although all PO distances are identical (1.529(4) Å), the OPO angles ranging from 108.06 (15) to 112.32 (31)°, show that [PO₄]³⁻ are rather distorted. Both sodium and bismuth cations are located in octahedral sites with corresponding mean distances of NaO and BiO equal to 2.428 and 2.386 Å, respectively. As expected from the close values of the ionic radii of Na⁺ and Bi³⁺, these distances lie in the same range.     

Ag3Bi14Br21: ein Subbromid mit Bi24+‐Hanteln und Bi95+‐Polyedern – Synthese,Kristallstruktur und Chemische Bindung

Ag₃Bi₁₄Br₂₁: a Subbromide with Bi₂⁴⁺ Dumbbells and Bi₉⁵⁺ Polyhedra – Synthesis, Crystal Structure and Chemical Bonding Black crystals of Ag₃Bi₁₄Br₂₁ = (Bi₉⁵⁺)[Ag₃Bi₃Br₁₅^3?](Bi₂Br₆^2?), the first argentiferous bismuth subhalide, were obtained from a stoichiometric melt of Ag, Bi, and BiBr₃. The compound crystallizes in the monoclinic space group P2₁/m with lattice parameters a = 1277.78(5) pm, b = 1466.87(6) pm, c = 1342.62(5) pm, and β = 108.47(1)° at 110(5) K. In contrast to all other bismuth subhalides that contain an electron‐rich transition metal, the silver atoms are not bonded to bismuth atoms. Instead they are integrated into the anionic bromometallate network, which consists of [MBr₆]‐octahedra (M = Ag, Bi) that share edges and vertices. These corrugated sheets alternate with tessellated layers formed by Bi₉⁵⁺ polycations and hitherto unknown (Bi^II₂Br₆)^2? groups. The latter anions contain Bi₂⁴⁺ dumbbells (299 pm) and can be represented by the structured formula [Br₂Bi^II(μ–Br)₂Bi^IIBr₂]^2?. The multi‐center bonding within the Bi₉⁵⁺ cluster and the bent single‐bond in the Bi₂ dumbbell can be visualized using the electron localization indicator (ELI‐D).     

Ein,altes‘ Rhodiumsulfid mit überraschender Struktur: Synthese,Kristallstruktur und elektronische Eigenschaften von Rh3S4

An ‘old' Rhodiumsulfide with surprising Structure – Synthesis, Crystal Structure, and Electronic Properties of Rh₃S₄ The reaction of rhodium with rhodium(III)‐chloride and sulfur at 1320 K in a sealed evacuated quartz glass ampoule yields silvery lustrous, air stable crystals of the rhodiumsulfide Rh₃S₄. Although a sulfide of this composition was described in 1935 a closer characterization has not been undertaken. Rh₃S₄ crystallizes in a new structure type in the monoclinic space group C2/m with a = 1029(2) pm, b = 1067(1) pm, c = 621.2(8) pm, β = 107.70(1)°. Besides strands of edge‐sharing RhS₆ octahedra which are connected by S₂ pairs (S–S = 220 pm), the crystal structure of Rh₃S₄ contains Rh₆ cluster rings in chair conformation with Rh–Rh single bond lengths of 270 pm. Both fragments are linked by common sulfur atoms. Extended Hückel calculations indicate bonding overlap for both S–S‐ and Rh–Rh‐interactions. Rh₃S₄ has a composition between the neighboring phases Rh₂S₃ and Rh₁₇S₁₅ and the structure combines typical fragments of both: RhS₆‐octahedra from Rh₂S₃ and domains of metal‐metal bonds as found in Rh₁₇S₁₅. Rh₃S₄ is a metallic conductor, down to 4.5 K the substance shows a weak, temperature independent paramagnetism.     

Über bismut-haltige heterocyclen: I. Methylierte und phenylierte bismocane,intra- und intermolekulare koordinationserhöhung an bismut(III)

Methyl and phenyl oxadithia and trithiabismocanes have been synthesized from methyl or phenyl diethoxybismutane and the respective dithiol. The light-sensitive compounds have been investigated by mass, vibrational and ¹³C NMR spectra: ν(BiMe) 470–460, ν(BiS₂) 300–240 cm^?1; δ(¹³Me) ?12 ppm. The crystal structure of 5-phenyl-1,4,6,5-oxadithiabismocane has been determined (R = 0.056). The eight-membered ring has the chair-chair conformation. Besides three direct bonds (BiPh 225(2), BiS 256.0(2) and 260.2(3) pm) there are one transannular (Bi?O 297(1) and two intermolecular contacts (Bi ?S 344.0(3) and 350.9(3) pm) to bismuth in resulting a ψ-monocapped octahedral sphere of coordination. These polyhedra are connected in sharing two different edges, and the crystal structure exhibits double chains of molecules.     

Synthesen,Kristallstrukturen und Drillingsbildung der Cluster‐Trimere Bi2[PtBi6Br12]3 und Bi2[PtBi6I12]3

Syntheses, Crystal Structures, and Triple Twinning of the Cluster Trimers Bi₂[PtBi₆Br₁₂]₃ and Bi₂[PtBi₆I₁₂]₃ Melting reactions of Bi with Pt and BiX₃ (X = Br, I) yield shiny black, air insensitive crystals of the subhalides Bi₂[PtBi₆X₁₂]. Bi₂[PtBi₆Br₁₂]₃ crystallizes in the monoclinic space group C2/m with lattice parameters a = 1617.6(2) pm, b = 1488.5(1) pm, c = 1752.4(2) pm, and β = 110.85(4)°. Bi₂[PtBi₆I₁₂]₃ adopts the triclinic space group with pseudo‐monoclinic lattice parameters a = 1711.2(2) pm, b = 1585.1(1) pm, c = 1865.7(2) pm, and α = 90°, β = 111.15(4)°, γ = 90°. The two homoeotypic compounds consist of cuboctahedral [Pt^?IIBi^II₆X^?I₁₂]^2? clusters that are concatenated into linear trimers by Bi^III atoms. The ordered distribution of Bi^III atoms destroys the inherent threefold rotation axes in the packing of cluster anions. As a consequence of the pseudosymmetry the crystals are triple twinned along [201]. Due to different orientations of the cluster trimers there are two Bi^II···X inter‐cluster bridges per Bi^II atom in Bi₂[PtBi₆Br₁₂]₃ but only one bridge in Bi₂[PtBi₆I₁₂]₃. The structure of the iodine compound can be deduced from the NaCl structure type, leaving 37 of 96 atomic positions unoccupied. The arrangement of the cuboctahedral clusters follows the motif of a body‐centered cubic packing.     

Spatial Separation of Covalent,Ionic, and Metallic Interactions in Mg11Rh18B8 and Mg3Rh5B3

The crystal structures of Mg₁₁Rh₁₈B₈ and Mg₃Rh₅B₃ have been investigated by using single‐crystal X‐ray diffraction. Mg₁₁Rh₁₈B₈: space group P4/mbm; a=17.9949(7), c=2.9271(1) Å; Z=2. Mg₃Rh₅B₃: space group Pmma; a=8.450(2), b=2.8644(6), c=11.602(2) Å; Z=2. Both crystal structures are characterized by trigonal prismatic coordination of the boron atoms by rhodium atoms. The [BRh₆] trigonal prisms form arrangements with different connectivity patterns. Analysis of the chemical bonding by means of the electron‐localizability/electron‐density approach reveals covalent B? Rh interactions in these arrangements and the formation of B? Rh polyanions. The magnesium atoms that are located inside the polyanions interact ionically with their environment, whereas, in the structure parts, which are mainly formed by Mg and Rh atoms, multicenter (metallic) interactions are observed. Diamagnetic behavior and metallic electron transport of the Mg₁₁Rh₁₈B₈ and Mg₃Rh₅B₃ phases are in agreement with the bonding picture and the band structure.     

Structure, and magnetic and transport behavior of twinned Ce2Rh3(Pb,Bi)5

Single crystals of a new compound, Ce₂Rh₃(Pb,Bi)₅, have been grown via a flux-growth technique using molten Pb as a solvent. The compound has been characterized by single crystal X-ray diffraction and found to be of the orthorhombic Y₂Rh₃Sn₅ structure type [Cmc2₁ (No. 36), Z=4] with lattice parameters a=4.5980(2), b=27.1000(17) and c=7.4310(4) Å, with V=925.95(9) Å³. Ce₂Rh₃(Pb,Bi)₅ has a complex crystal structure containing Ce atoms encased in Rh-X (X=Pb/Bi) pentagonal and octagonal channels in [100], with polyanions similar to those found in Ce₂Au₃In₅ and Yb₂Pt₃Sn₅. Magnetization measurements find that Ce₂Rh₃(Pb,Bi)₅ is a quasi-two-dimensional system, where the Ce moments are spatially well-localized. Heat capacity measurements show a transition at the Néel temperature of 1.5 K. Evidence for Fermi surface nesting is found in electrical resistivity measurements, and we argue that Ce₂Rh₃(Pb,Bi)₅ is very near a metal-insulator transition in zero field.     

Wismutmonojodid BiJ,eine Verbindung mit Bi(O) und Bi(II)

Bismuth Monoiodide, a Compound with Bi(O) and Bi(II) Bismuth monoiodide was synthesized in closed tubes from the elements as well as from Bi and HgI₂ as a black coloured crystalline compound. With increasing temperature BiI passes two transitions. α-BiI is stable below 370 K and changes to β-BiI by a martensitic transition. γ-BiI is the stable modification above 564 K and decomposes at 585 K peritectically to BiI₃ and a lower iodide. All three modification crystallize in the monoclinic space group C2/m. The structures (single crystal studies) of α-BiI and β-BiI are characterized by onedimensional infinite chains [Bi₄I₄] with covalent bonds but only weak interactions in between. The [Bi₄I₄]-chains are built up by two completely different Bi atoms. Bi(A) is only bonded to three Bi whereas Bi(B) has bonds to one Bi and four I. The average bond lengths are Bi? Bi = 304.5 pm and Bi? I = 313.7 pm respectively. The configuration of the Bi(A) atoms is typical for Bi^O and that one of the Bi(B) atoms is characteristic for Bi²⁺ with the electron configuration s²p¹. Therefore, α-BiI and β-BiI are mixed valence compounds [Bi^OBi²⁺I₄]. The structures are variants of the simple cubic polonium type of structure and differ in the stacking of connected units. The structures and their transitions, the possible configurations for monohalides BiX on principle as well as the energy balances of the disproportionation of Bi⁺ are discussed together in detail.     

Synthesis, crystal structure, and photocatalytic activity of the new three-layer aurivillius phases, Bi2ASrTi2TaO12 (A=Bi, La)

Two new three-layer Aurivillius phases Bi₂ASrTi₂TaO₁₂ (A=Bi, La) have been synthesized. The detailed structure determination of Bi₂ASrTi₂TaO₁₂ (A=Bi, La) performed by powder X-ray diffraction (XRD) and selected area electron microscopy (SAED) shows that they all crystallize in the space group I/4mmm. UV-visible diffuse reflection spectrum of the prepared Bi₂ASrTi₂TaO₁₂ (A=Bi, La) indicates that it had absorption in the ultraviolet (UV) region. The photocatalytic activity of the Bi₂ASrTi₂TaO₁₂ (A=Bi, La) powders was evaluated by degradation of rhodamine B (RB) molecules in water under UV light irradiation. The results showed that Bi₂ASrTi₂TaO₁₂ (A=Bi, La) has high photocatalytic activity at room temperature. Therefore, the preparation and properties studies of Bi₂ASrTi₂TaO₁₂ (A=Bi, La) with a three-layer Aurivillius structure suggest potential future applications in photocatalysis.     

Die Cluster‐Salze Bi14Si2MI12 (M = Rh,Ir): [Bi8Si2]‐ und [MBi6I12]‐Baugruppen in CsCl‐analoger Anordnung

The Cluster Salts Bi₁₄Si₂MI₁₂ (M = Rh, Ir): [Bi₈Si₂] and [MBi₆I₁₂] Building Groups in CsCl‐like Structure The reaction of bismuth and iridium with iodine in evacuated quartz ampoules at 1320 K yields black, air insensitive crystals of Bi₁₄Si₂IrI₁₂. The silicon therein is abstracted from the ampoule material whereby the oxygen is gettered in BiOI. The synthesis of Bi₁₄Si₂RhI₁₂ requires the addition of niobium, which gives NbOI₂ with the oxygen originating from the SiO₂. X‐ray diffraction on single crystals showed that the two isotypic compounds crystallize in the space groups P 4/m c c with a = 1018.3(1), c = 2020.1(4) pm for M = Ir, and a = 1019.0(1), c = 2018.7(4) pm for M = Rh. The crystal structures consist of two types of isolated clusters, which form a CsCl‐like packing. In the [MBi₆I₁₂] cuboctahedron the central transition metal atom is octahedrally surrounded by bismuth atoms, and the iodine atoms bridge the edges of the octahedron. The [Bi₈Si₂] polyhedron is a tetragonal antiprism of bismuth atoms of which square faces are capped by silicon atoms. Based on crystal chemistry and band structure calculations the compounds may be formulated as cluster salts [Bi₈Si₂]³⁺[MBi₆I₁₂]^3–. Measurements of the electrical conductivity showed that Bi₁₄Si₂IrI₁₂ is a semiconductor with a band gap of about 0.1 eV. A single unpaired electron out of 1903 electrons per formula causes paramagnetic behaviour that is superposed by strong diamagnetic contributions.     

High nuclearity PtRh carbonyl clusters. Synthesis and X-ray characterization of the [Pt2Rh9(CO)22]3− trianion

The new mixed PtRh cluster trianion [Pt₂Rh₉(CO)₂₂]^3? has been isolated as a minor product of the pyrolysis of [PtRh₅(CO)₁₅]^?, and has been characterized by X-ray diffraction. The metal skeleton, which has ideal D_3h symmetry, consists of three face-to-face condensed octahedra, as previously found in the isoelectronic species [Rh₁₁CO)₂₃]^3?, with the Pt atoms on the three-fold axis, in the positions of maximum MM connectivity.     

The Topochemical Pseudomorphosis of a Chloride into a Bismuthide

The heterogeneous reaction of crystals of the novel intermetallic subhalide Bi₁₂Rh₃Cl₂ with a solution of n‐butyllithium at 70 °C led to the complete topochemical exchange of chloride ions for bismuth atoms, that is, the transformation into the isostructural metastable intermetallic superconductor Bi₁₄Rh₃. The crystals underwent the reductive pseudomorphosis almost unchanged except some fissures perpendicular to the a‐axis. Detailed inspections of the transformed crystals by electron microscopy indicated no volume defects that would indicate internal chemical reactions. Thus, extensive mass transport must have occurred through the seemingly dense crystal structure. An efficient transport mechanism, based on an unusual breathing mode of the three‐dimensional network formed by edge‐sharing [RhBi₈] cubes and antiprisms, is proposed. The replacement of ionic interaction in the chloride by metallic bonding in the binary intermetallic compound closes the pseudo gap in the density of states at the Fermi level. As a result, the rod‐packing of conducting, yet electrically isolated strands of [RhBi₈] cubes in Bi₁₂Rh₃Cl₂ turns into the three‐dimensional metal Bi₁₄Rh₃.     

Synthesis,crystal structure and physical properties of Yb11Bi10 − xSnx

The intermetallic phase Yb₁₁Bi_{10 − x}Sn_x (x = 0 and 4.8) crystallizing in the Ho₁₁Ge₁₀ structure type was synthesized and characterized. The crystal structure was established by single-crystal X-ray diffraction data in the tetragonal space group I4/mmm (no.139), Pearson code tI84, Z = 4, a = 12.2043(4) Å, c = 17.7227(9) Å, and V = 2639.7(2) Å³, R_gt(F) = 0.040, 763 observed reflections for Yb₁₁Bi₁₀, and a = 12.0183(5) Å, c = 17.413(1) Å, and V = 2515.1(2) Å³, R_gt(F) = 0.027, 762 observed reflections for Yb₁₁Bi_5.2Sn_4.8. The crystal structure of Yb₁₁Bi₁₀ contains three discrete anionic moieties: isolated Bi³⁻ anions, Bi₂⁴⁻ dimers and Bi₄⁴⁻ squares. In Yb₁₁Bi_5.2Sn_4.8, the square units are formed solely by Sn, and the structure shows a mixed Bi/Sn occupancy at the 8i and 16m Wyckoff sites. Magnetization measurements show that the title phase contains ytterbium exclusively in the 4f¹⁴ configuration up to 400 K. The Yb-L_III X-ray absorption spectrum attests also the presence of Yb with a 4f¹⁴ (Yb²⁺) configuration for Yb₁₁Bi₁₀, while the average valence of ytterbium was found to be 2.09 for Yb₁₁Bi_5.2Sn_4.8.