Neue thermische Abbauprodukte von Ln2CeMO6Cl3 (M = Nb,Ta; Ln = La–Sm) – Darstellung von strukturverwandtem (La, Tb)3,5TaO6Cl4–x

Contributions on the Investigation of Inorganic Nonstoichiometric Compounds. XLV. New Thermal Decomposition Products of Ln₂CeMO₆Cl₃ – Preparation of Structure‐related (La, Tb)_3.5TaO₆Cl_4–x The thermal decomposition (T £ 900–1050°C) of Ln₂CeMO₆Cl₃ (M = Nb, Ta; Ln = La, Ce, Pr, Nd, Sm) leads to the formation of two mixed‐valenced phases (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ‘‘AB”︁”︁) and (Ln, Ce)_3.5MO₆Cl_4–x (phase ‘‘BB”︁”︁) and to the formation of chlorine according to redox‐reactions between Ce⁴⁺ and Cl^–. Single crystals of both phases (Ln, Ce)_3.25MO₆Cl_3.5–x (‘‘AB”︁”︁) and (Ln, Ce)_3.5MO₆Cl_4–x (‘‘BB”︁”︁) were obtained by chemical transport reactions using both powder of Ln₂CeMO₆Cl₃ (phase ‘‘A”︁”︁) and powder of (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ‘‘AB”︁”︁) as starting materials and chlorine (p{Cl₂; 298 K} = 1 atm) or HCl (p{HCl; 298 K} = 1 atm) as transport agent. A crystal of (La, Ce)_3.25NbO₆Cl_3.5–x (”︁AB”︁”︁) (space group: C2/m, a = 35.288(1) Å, b = 5.418(5) Å, c = 9.522(1) Å, β = 98.95(7)°, Z = 4) was investigated by x‐ray diffraction methods, a crystal of (Pr, Ce)_3.5NbO₆Cl_4–x (”︁BB”︁”︁) was investigated by synchrotron radiation (λ = 0.56 Å) diffraction methods. The lattice constants are a = 18.863(6) Å, b = 5.454(5) Å, c = 9.527(6) Å, β = 102.44(3)° and Z = 4. Structure determination in the space group C2/m (No. 12) let to R1 = 0.0313. Main building units are NbO₆‐polyhedra with slightly distorted trigonally prismatic environment for Nb and chains of face‐sharing Cl₆‐octahedra along [010]. The rare earth ions are coordinated by chlorine and oxygen atoms. These main structure features confirmed the expected relation to the starting material Ln₂CeMO₆Cl₃ (phase ”︁A”︁”︁) and to (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ”︁AB”︁”︁).     

The Crystal Structure of YPdSi,the Isotypic Compounds LnPdSi (Ln = Gd–Lu), and their Structural Relation to some other Equiatomic Compounds of the Rare Earth and Transition Metals with Main Group Elements

The nine title compounds were prepared from the elements by arc-melting and subsequent heat treatment in resistance and high-frequency furnaces. The crystal structure of these isotypic compounds was determined for YPdSi from single-crystal X-ray diffractometer data: Pmmn, a = 430.8(1) pm, b = 1391.2(1) pm, c = 743.1(1) pm, Z = 8, R = 0.024 for 417 structure factors and 40 variable parameters. The crystal structures of the isotypic compounds GdPdSi and ErPdSi were also refined from single-crystal data. The structure is of a new type. It consists of condensed, six-membered rings of alternating palladium and silicon atoms with Pd–Si bond distances varying between 249.6 and 258.8 pm. These two-dimensionally infinite nets are connected to each other via weak Pd–Si and Si–Si bonds with bond distances of 276.3 and 259.5 pm. The rare earth atoms are situated above and below the six-membered palladium-silicon rings in a manner as it is known for the aluminum atoms in the AlB₂ type structure. The crystal-chemical similarities and topologies of several structures derived from the aristotype AlB₂ (including those of BaPtSb, EuAuGe, KHg₂, ZrBeSi, and TiNiSi) are described, emphasizing their group-subgroup relationships. The previously reported compound ”︁Er₂Pd₂Si”︁”︁ has the same structure as has been found here for ErPdSi.     

Selten-Erd-Hydrogensulfate M(HSO4)3 (M = La,Ce–Nd): Derivate des UCl3-Typs

Rare Earth Hydrogensulfates M(HSO₄)₃ (M = La, Ce–Nd): Derivatives of the UCl₃ Type of Structure Hydrogensulfates of the lighter lanthanides are obtained from the reaction of the respective anhydrous sulfates with conc. sulfuric acid at 200 °C. According to X-ray single crystal determinations on La(HSO₄)₃ (hexagonal, P6₃/m, a = 945.64(9) pm, c = 590.87(5) pm), Ce(HSO₄)₃ (a = 943.34(10) pm, c = 587.88(5) pm), Pr(HSO₄)₃ (hexagonal, P6₃/m, a = 939.8(1) pm, c = 584.82(9) pm) and Nd(HSO₄)₃ (hexagonal, P6₃/m, a = 935.67(8) pm, c = 582.36(4) pm) they all crystallize analogous to the UCl₃ type of structure with nine-coordinate M³⁺ ions. The OH groups of the [HOSO₃]^– ”︁tetrahedra”︁”︁ build up channels parallel [00.1] typical for this type of structure. Hydrogen bonding, however, is only weak in these compounds.     

Synthese und Kristallstruktur von Ti12Sn3O10 – einem niedervalenten Oxid des Titans mit oxidischem Gerüst und intermetallischen „Inseln”︁

Synthesis and Crystal Structure of Ti₁₂Sn₃O₁₀ – a Low Valent Oxide of Titanium with an Oxidic Network and Intermetallic ”︁Islands”︁”︁ The new ternary compound Ti₁₂Sn₃O₁₀ is obtained by the reaction of Ti, TiO₂ and Sn at 1500 °C. According to the single crystal structure analysis (cubic, space group Fm3m, a = 13.5652(9) Å, Z = 8, wR₂(I) = 0.048, R₁(F) = 0.020) the air stable compound represents a new structure type combining structural features of oxides and intermetallics. While tin is surrounded only by titanium the five different Ti atoms have oxidic and metallic coordination spheres as well, explaining the quite low averaged oxidation number. The crystal structure is characterized by a threedimensional net of Ti₄O‐tetrahedra and trigonal bipyramides Ti₅O. In the voids there are intermetallic ”︁islands”︁”︁ of a composition Ti₃₃Sn₆ with a diameter of about 10 Å.     

Kristallstrukturen und chemische Bindung von AM2GeSe4 (A = Sr,Ba; M = Cu,Ag)

New Noncentrosymmetric Selenogermanates. I. Crystal Structures and Chemical Bonding of AM ₂GeSe₄ ( A = Sr, Ba; M = Cu, Ag) Three new quaternary selenogermanates were synthesized by heating the elements at 983–1073 K. Their crystal structures were determined by single crystal X‐ray methods. The dark red semiconductors crystallize in noncentrosymmetric space groups. SrCu₂GeSe₄ (Ama2, a = 10.807(4) Å, b = 10.735(4) Å, c = 6.541(2) Å, Z = 4) forms a new structure type, whereas BaCu₂GeSe₄ (P3₁, a = 6.490(1) Å, c = 16.355(3) Å, Z = 3) and BaAg₂GeSe₄ (I222, a = 7.058(1) Å, b = 7.263(1) Å, c = 8.253(2) Å, Z = 2) crystallize in structures known from thiostannates. Main structural features are almost regular GeSe₄‐, but distorted CuSe₄‐ or AgSe₄‐tetrahedra sharing corners or edges. Eight selenium atoms coordinate the alkaline earth atoms in the voids of these three dimensional tetrahedral networks. Chemical bonding and the electronic structure are elucidated by self‐consistent band structure calculations and the COHP method. The electron density and the electron localization function ELF of SrCu₂GeSe₄ reveal a significant stronger covalent character for the Ge–Se bonds compared with the Cu–Se bonds. For this reason the GeSe₄ tetrahedra appear as quasi molecular entities, arranged spatially according to the motifs of closest packing. The metal atoms occupy the tetrahedral and octahedral voids of these “tetrahedra packing”. This concept allows to derive the structures of AM₂GeSe₄‐compounds from simple binary structure types as Li₃Bi or Ni₂In.     

Synthese und Kristallstruktur von Hydrogenselenaten zweiwertiger Metalle – M(HSeO4)2 (M = Mg,Mn, Zn) und M(HSeO4)2 · H2O (M = Mn,Cd)

Synthesis and Crystal Structure of Hydrogen Selenates of Divalent Metals – M(HSeO₄)₂ (M = Mg, Mn, Zn) and M(HSeO₄)₂ · H₂O (M = Mn, Cd) New hydrogen selenates M(HSeO₄)₂ (M = Mg, Mn, Zn) and M(HSeO₄)₂ · H₂O (M = Mn, Cd) have been synthesized using MSeO₄ (M = Mg, Mn, Zn, Cd) and 90% selenic acid as starting materials. The crystal structures have been determined by X-ray single crystal crystallography. The compounds M(HSeO₄)₂ (M = Mg, Zn) belong to the structure type of Mg(HSO₄)₂, whereas Mn(HSeO₄)₂ forms a new structure type. Both hydrogen selenate monohydrates are isotypic to Mg(HSO₄)₂ · H₂O. In all compounds the metal atoms are octahedrally coordinated by oxygen atoms of different HSeO₄-tetrahedra. In the HSeO₄-tetrahedra the Se–OH-distances (mean value 1.70 Å) are about 0.1 Å longer than Se–O-distances (mean value 1.62 Å). In the structure of M(HSeO₄)₂ (M = Mg, Zn) there are zigzag chains of hydrogen bonded HSeO₄-tetrahedra. The structure of Mn(HSeO₄)₂ is characterized by chains of HSeO₄-tetrahedra in form of screws. Hydrogen bonds from and to water molecules connect double layers of MO₆-octahedra and HSeO₄-tetrahedra in the structures of M(HSeO₄)₂ · H₂O.     

Organometallated Halonium Salts of the Type [{Cp(CO)2Fe}2X]SbY6 (X = Cl,Br, I; Y = F,Cl)

The reaction of CpFe(CO)₂X (X = Cl, Br, I) with SbY₅ (Y = F, Cl) in toluene leads to the cationic, halogen‐bridged compounds [{Cp(CO)₂Fe}₂X]SbY₆ ( 1 – 6 ). The halide of CpFe(CO)₂X is eliminated by the Lewis acid SbY₅, and the fragment “CpFe(CO)₂⁺” reacts with further CpFe(CO)₂X to form the halogen bridge between both the organometallic substituents. The exclusive formation of the counter anion SbY₆^– is caused by the oxidizing action of the antimony pentahalides, by which SbY₃ and the interhalogens XY are always obtained. The compounds have been characterized by their NMR‐, IR‐ and Mass spectra, the compounds 1 – 3 and 6 additionally by single crystal structure analyses. They show decreasing bond angles Fe–X–Fe following the range Cl → Br → I and the VSEPR concept; the two CpFe(CO)₂ groups are staggered with the dihedral angle Cp(centre)–Fe–Fe–Cp(centre) of about 160°.     

Synthese,Struktur und Eigenschaften von [nacnac]MX3‐Verbindungen (M = Ge,Sn; X = Cl,Br, I)

Synthesis, Structure, and Properties of [nacnac]MX₃ Compounds (M = Ge, Sn; X = Cl, Br, I) Reactions of [nacnac]Li [(2,6‐ⁱPr₂C₆H₃)NC(Me)C(H)C(Me)N(2,6‐ⁱPr₂C₆H₃)]Li ( 1 ) with SnX₄ (X = Cl, Br, I) and GeCl₄ in Et₂O resulted in metallacyclic compounds with different structural moieties. In the [nacnac]SnX₃ compounds (X = Cl 2 , Br 3 , I 4 ) the tin atom is five coordinated and part of a six‐membered ring. The Sn–N‐bond length of 3 is 2.163(4) Å and 2.176(5) Å of 4 . The five coordinated germanium of the [nacnac]GeCl₃ compound 5 shows in addition to the three chlorine atoms further bonds to a carbon and to a nitrogen atom. In contrast to the known compounds with the [nacnac] ligand the afore mentioned reaction creates a carbon–metal‐bond (1.971(3) Å) forming a four‐membered ring. The Ge–N bond length (2.419(2) Å) indicates the formation of a weakly coordinating bond.     

Rubidium‐ und Caesium‐Verbindungen mit dem Isopolyanion [Ta6O19]8– – Synthesen,Kristallstrukturen, thermische und schwingungsspektroskopische Untersuchungen der Oxotantalate A8[Ta6O19] · n H2O (A = Rb,Cs; n = 0, 4, 14)

Rubidium und Caesium Compounds with the Isopolyanion [Ta₆O₁₉]^8– – Synthesis, Crystal Structures, Thermogravimetric and Vibrational Spectrocopic Analysis of the Oxotantalates A₈[Ta₆O₁₉] · n H₂O (A = Rb, Cs; n = 0, 4, 14) The compounds A₈[Ta₆O₁₉] · n H₂O (A = Rb, Cs; n = 0, 4, 14) contain the isopoly anion [Ta₆O₁₉]^8–, which consists of six [TaO₆] octahedra connected via corners to form a large octahedron. They transform into each other by reversible hydratation/dehydratation processes, as shown from thermoanalytic measurements (TG/DSC), and show also structural similarities. Cs₈[Ta₆O₁₉] (tetragonal, I4/m, a = 985.9(1) pm, c = 1403.3(1) pm, Z = 2), the isotypic phases A₈[Ta₆O₁₉] · 14 H₂O (A = Rb/Cs; monoclinic, P2₁/n, a = 1031.30(6)/1055.4(1) pm, b = 1590.72(9)/1614.9(6) pm, c = 1150.43(6)/1171.4(1) pm, β = 100.060(1)/99.97(2)°, Z = 2) and Rb₈[Ta₆O₁₉] · 4 H₂O (monoclinic, C2/c, a = 1216.9(4) pm, b = 1459.2(5) pm, c = 1414.7(4) pm, β = 90.734(6)°, Z = 4) have been characterised on the basis of single crystal x‐ray data. Furthermore the RAMAN spectra allow a detailled comparison of the hexatantalate ions in the four compounds.     

Neue Rhodiumverbindungen mit LiCo6P4‐Struktur

New Rhodium Compounds with the LiCo₆P₄ Type Structure Five new phosphides and arsenides respectively of the formula ARh₆X₄ (A: Mg–Sr, Yb; X: P, As) were prepared by heating mixtures of the elements and investigated by means of single crystal X‐ray methods. They are isotypic and crystallize in the LiCo₆P₄ type structure (P6m2; Z = 1) (lattice constants see ”︁Inhaltsübersicht”︁”︁). The compounds belong to the large family of phosphides and arsenides, which have a metal : non‐metal ratio of about 2 : 1. Their structures are characterized by the environment of phosphorus and arsenic respectively, which is composed of trigonal prisms of metal atoms with additional metal atoms capping the rectangular faces of the prisms.     

Amido-Komplexe von Mangan(II). Synthese und Kristallstrukturen von [Mn(NPh2)2(THF)]2 und Na2[Mn(NPh2)4] · 2 C7H8

Amido Complexes of Manganese(II). Syntheses and Crystal Structures of [Mn(NPh₂)₂(THF)]₂ and Na₂[Mn(NPh₂)₄] · 2 C₇H₈ The silylated amido complex [Mn{N(SiMe₃)₂}₂ · (THF)] reacts in toluene solution with diphenylamine under ligand exchange to form the diphenylamido complex [Mn(NPh₂)₂(THF)]₂ ( 1 ), which forms orange-red columnar crystals. 1 reacts in THF solution with NaN(SiMe₃)₂ and after crystallization from toluene yellow-orange Na₂[Mn(NPh₂)₄] · 2 C₇H₈ ( 2 ) is obtained. According to the crystal structure analyses the manganese atoms in 1 (space group P2₁/c, Z = 2) are linked via the N atoms of two of the NPh₂^– groups to form centrosymmetric Mn₂N₂ four-membered rings with Mn–N bonds of almost the same length. 2 (space group I4₁/a, Z = 4) forms a three-dimensional space-lattice structure, which arises from ”︁inner solvation”︁”︁ of the sodium atoms with the phenyl rings of the NPh₂^– group.     

Homoatomare Cluster E93– mit E = Ge,Sn und Pb: EPR‐Spektren,Magnetismus und Elektrochemie

Homoatomic Clusters E₉^3– with E = Ge, Sn, and Pb: EPR Spectra, Magnetism and Electrochemistry The properties of the compounds [K‐([2.2.2]‐crypt)]₃E₉ (E = Ge ( 1 ), Sn ( 2 ), Pb ( 3 )), which contain isolated E₉ units, have been examined by EPR measurements at room temperature and at 77 K, magnetic susceptibility measurements in the range from 2 K to 300 K and cyclovoltammetric experiments. The EPR signals of powder samples and of single crystals are analyzed using three g tensor components, indicating low symmetric E₉^3– clusters. Magnetic susceptibility data of 2 and 3 follow the expression (χ_mol = C/(T – θ_p) + χ₀, with θ_p ≈ 0 and C corresponding to the presence of about 50% paramagnetic E₉^3– species (S = ¹/₂). In solution, 2 and 3 show irreversible oxidation processes. Current intensities and peak forms indicate that adsorption processes play an important role irrespective of the material of the working electrode (silver, platinum, glassy carbon).     

Preparation and Crystal Structure of the Ternary Lanthanoid Nickel Arsenides Ln13Ni25As19 (Ln = Tm,Yb, and Lu)

The title compounds were prepared by reaction of the elemental components at high temperatures. They crystallize with a new structure type which was determined from single‐crystal X‐ray data of Tm₁₃Ni₂₅As₁₉: P 6, a = 1621.9(4) pm, c = 387.78(8) pm, Z = 1, R = 0.025 for 3164 structure factors and 119 variable parameters. The refinement of the occupancy parameters suggested a mixed Tm/Ni occupancy for one metal position and defects for one nickel site resulting in the composition Tm_12.57(1)Ni_25.22(2)As₁₉. These arsenides belong to a large structural family with a metal to metalloid ratio of 2 : 1.     

Crystal Structures,Bonding and Electronic Structures of MM′As,a Series of New Ternary Arsenides (M = Zr,Hf; M′ = Fe,Co, Ni)

All six new arsenides were prepared by arc-melting of preheated mixtures of the monoarsenides MAs with the 3d metals Fe, Co, and Ni, respectively. The isostructural title compounds all form the Co₂Si structure type, in contrast to the corresponding phosphides with ZrNiP occurring in the Ni₂In type. The anomalous expansions of the unit cells from ZrCoAs to ZrNiAs (V = 178.5(3) ų versus V = 182.5(1) ų) and from HfCoAs to HfNiAs (V = 175.03(5) ų versus V = 177.0(1) ų) can be understood based on Extended Hückel calculations of the electronic structure of HfCoAs.     

Ternäre Selenide der Lanthanide mit Alkalimetallen: I. Der Formeltyp Cs3M7Se12 (M = Gd–Ho)

Ternary Selenides of the Lanthanides with Alkali Metals: I. The Composition Cs₃M₇Se₁₂ (M = Gd–Ho) When the lanthanides gadolinium, terbium, dysprosium and holmium are oxidized with selenium in a molar ratio of 2 : 3 in evacuated silica tubes (700 °C, 7 d) and CsCl is added, ternary cesium lanthanide selenides with the composition Cs₃M₇Se₁₂ (M = Gd–Ho) readily form. Surplus CsCl as flux accelerates the crystallization of the yellow, transparent needles. Since these crystals are stable to hydrolysis, excess CsCl and the chloride by-products (e. g. Cs₃MCl₆) can be rinsed off easily with water. The crystal structure of the flanking representatives Cs₃Gd₇Se₁₂ and Cs₃Ho₇Se₁₂ (orthorhombic, Pnnm (no. 58), Z = 2; Cs₃Gd₇Se₁₂: a = 1294.8(3), b = 2650.1(5), c = 419.36(9) pm, R₁ = 0.098, wR₂ = 0.173; Cs₃Ho₇Se₁₂: a = 1280.4(3), b = 2621.2(5), c = 412.13(8) pm, R₁ = 0.096, wR₂ = 0.126) was determined and refined on the basis of X-ray data from single crystals. With the help of powder diffraction Cs₃Tb₇Se₁₂ (a = 1289.4(1), b = 2640.3(2), c = 416.82(3) pm) and Cs₃Dy₇Se₁₂ (a = 1285.3(1), b = 2631.5(2), c = 414.47(3) pm) were established to be isotypic. The four new compounds crystallize isostructurally with Cs₃Y₇Se₁₂, so that a three-dimensional framework {[M₇Se₁₂]^3–} of vertex- and edge-sharing [MSe₆] octahedra is present. Wave-like, one-dimensional infinite ”︁triple-channels”︁ run through the structure along [001] which are filled with two crystallographically different Cs⁺ cations (CN(Cs1) = 7 + 1, CN(Cs2) = 6). Owing to much too close Cs⁺–Cs⁺ contacts only a semi-occupation is possible for the Cs2 position which the structure refinements inevitably prove.     

Ternäre Alkalimetall‐Übergangsmetall‐Acetylide der Zusammensetzung A2MC2 mit A = Rb,Cs und M = Pd,Pt

Ternary Alkali Metal Transition Metal Acetylides A₂MC₂ with A = Rb, Cs, and M = Pd, Pt By the reaction of Rb₂C₂ and Cs₂C₂ with palladium or platinum powder in sealed glass ampoules at 653 K ternary acetylides A₂MC₂ (A = Rb, Cs; M = Pd, Pt) were obtained. Their crystal structures were solved and refined by means of X‐ray powder investigations (Na₂PdC₂ structure type, P 3 m1, Z = 1). The crystal structures are characterised by [M(C₂)_2/2^2–] chains separated by the alkali metals. Raman spectroscopic investigations revealed wave numbers of the C–C stretching vibrations between 1833 and 1842 cm^–1, which are in good agreement with the results of the analogous sodium and potassium compounds.     

Darstellung,Kristallstruktur und Eigenschaften von Ln3AuO6 (Ln = Sm,Eu, Gd)

Syntheses, Crystal Structures, and Properties of Ln₃AuO₆ (Ln = Sm, Eu, Gd) The title compounds have been prepared from amorphous Au₂O₃ · x H₂O (x = 1–3) and Ln₂O₃ (Ln = Nd, Sm, Eu) via solid state reaction under elevated oxygen pressure adding KOH as mineralizing agent. They crystallize in a new structure type (triclinic, P1, Z = 1, Sm₃AuO₆: a = 3.7272(2) Å, b = 5.6311(2) Å, c = 7.0734(3) Å, α = 90.32(2)°, β = 103.983(3)°, γ = 90.822(2)°, 125 powder intensities, R_p = 2.57%, Eu₃AuO₆: a = 3.7012(2) Å, b = 5.6134(2) Å, c = 7.0652(4) Å, α = 90.838(3)°, β = 102.956(3)°, γ = 90.909(2)°, 122 powder intensities, R_p = 3.16%, Gd₃AuO₆: a = 3.6720(2) Å, b = 5.5977(2) Å, c = 7.0636(2) Å, α = 90.509(2)°, β = 102.889(3)°, γ = 91.068(2)°, 3424 reflections, R₁ = 12.90%). The crystal structure was solved and refined from single crystal data of Gd₃AuO₆. The structures of Sm₃AuO₆ and Eu₃AuO₆ were refined from powder diffraction data. The isolated square planar AuO₄ units are stacked along the a‐axis and are linked by LnO₆‐ and LnO₆₊₁‐polyhedra. One of the oxygen atoms is exclusively coordinated by trivalent lanthanides, in tetrahedral geometry. The lanthanoid aurates decompose between 700 and 900 °C into Ln₂O₃, Au and O₂. The magnetic moments μ_eff(Gd₃AuO₆) = 7.9 μ_B and, at 20 °C respectively, μ_eff(Sm₃AuO₆) = 1.55 μ_B as well as μ_eff(Eu₃AuO₆) = 3.5 μ_B confirm that the lanthanides are trivalent. The UV/VIS absorption spectra can be interpreted at assuming free ions.     

Symmetry‐Breaking Transitions in HoCuAs2–xPx and ErCuAs2–xPx (x = 0–2): Crystal Structure,Application of Landau Theory,Magnetic and Electrical Properties

Crystal structures of compounds undergoing symmetry‐breaking transitions have been investigated by the X‐ray single crystal and powder methods. While the phases HoCuAs₂ through HoCuAs_1.33P_0.67 and ErCuAs₂ through ErCuAsP retain the tetragonal HfCuSi₂ structure (P4/nmm space group), the compounds HoCuAsP through HoCuAs_0.33P_1.67 and ErCuAs_0.67P_1.33 through ErCuAs_0.33P_1.67 undergo orthorhombic distortions to the GdCuAs_1.15P_0.85 structure (Pmmn space group). Further distortions follow in the phosphides: HoCuP₂ adopts a larger orthorhombic cell (Cmma, a = 5.273(3), b = 5.305(3), c = 9.645(5) Å) and ErCuP₂ has a monoclinic cell with a doubled parameter, the b parameter in the monoclinic cell (P2₁/n, a = 3.737(3), b = 19.239(15), c = 3.728(3) Å, β = 90.09(1)°). Zigzag chains are formed in the phosphorus layer of ErCuP₂. According to Landau theory the transitions from HoCuAs_1.33P_0.67 to HoCuAsP and from ErCuAsP to ErCuAs_0.67P_1.33 can be continuous, and the transitions from HoCuAs_0.33P_1.67 to HoCuP₂ and from ErCuAs_0.33P_1.67 to ErCuP₂ are necessarily first‐order. The results of magnetic and electrical measurements for HoCuAs₂ and HoCuP₂ are reported. Due to the magnetic moments localized on Ho atoms both compounds order antiferromagnetically at low temperatures. They exhibit metallic conductivity.     

Das System KCl/ErCl3 und die Modifikationen der Verbindungen K3LnCl6 (Ln = Ce–Lu,Y)

The System KCl/ErCl₃ and the Modifications of Compounds K₃LnCl₆ (Ln = Ce–Lu, Y) The phase diagram of the system KCl/ErCl₃ was investigated by DTA and XRD. Two compounds exist: KEr₂Cl₇ incongruently and K₃ErCl₆ congruently melting. Their thermodynamic functions for the formation from KCl and ErCl₃ were determined by solution calorimetry and emf vs T measurements in a galvanic cell for solid electrolytes. Both compounds are stable down to 0 K. – K₃ErCl₃ exists in three modifications. The structure of T–K₃ErCl₆ was determined by single crystal measurements: S.G. P2₁/c; Z = 4; a = 1309.8(5), b = 767.1(3), c = 1252.6(4) pm, β = 109.94(2)°. – A survey of all known results on compounds K₃LnCl₆ reveals, that from Ln = Ce to Ln = Ho they only are stable at higher temperatures, > 521 °C (Ce) and > –27 °C (Ho), resp.     

Disupersilylsilanide M(SiHR*2)2 der Zinkgruppenmetalle (M = Zn,Cd, Hg; R* = SitBu3): Synthesen,Charakterisierung und Strukturen

Disupersilylsilanides M(SiHR^*₂)₂ of Metals of the Zinc Group (M = Zn, Cd, Hg; R* = Si t Bu₃): Syntheses, Characterization, and Structures Bis(disupersilyl)silylmetals M(SiHR )₂ (R* = Supersilyl = SitBu₃) with M = Zn, Cd, Hg are obtained in tetrahydrofuran/benzene/pentane by the reaction of NaSiHR with ZnCl₂, CdI₂, HgCl₂ in the molar ratio 2 : 1. The compounds form colorless, in organic media soluble, not hydrolysis‐ and air‐sensitive crystals, the stabilities of which for thermolysis or photolysis decrease in the row Zn > Hg > Cd compound. According to X‐ray structure analyses, the compounds M(SiHR )₂ are monomeric with a – to date not observed – non‐linear framework –M– (angle SiMSi for M(SiHR )₂ with M = Zn/Cd/Hg 170.7/174.2/174.4°).