Neue gemischtvalente ternäre Bromide und Iodide mit Dysprosium und Thulium vom Typ A5M3X12

New Mixed‐Valence Ternary Bromides and Iodides of Dysprosium and Thulium of the Type A₅M₃X₁₂ The new ternary mixed‐valence bromides and iodides of dysprosium and thulium Rb₅Dy₃Br₁₂, Rb₅Tm₃Br₁₂, K₅Dy₃I₁₂, K₅Tm₃I₁₂, Rb₅Dy₃I₁₂ and Rb₅Tm₃I₁₂ were obtained by metallothermic reduction of DyBr₃, TmBr₃, DyI₃ and TmI₃, respectively, with potassium and rubidium in the presence of the respective alkali metal halides in sealed niobium containers. The crystal structure was determined for the example of K₅Dy₃I₁₂ (hexagonal, P 6 2m, Z = 1; a = 1446.7(2), c = 473.3(1) pm): DyI₆ octahedra are connected via common trans edges to chains. Magnetic measurements on X‐ray pure samples show Curie‐Weiss behaviour at sufficiently high temperatures. Antiferromagnetic coupling occurs at low temperatures.     

Eine Strukturvariante zum NaErCl4/α-NiWO4-Typ für ternäre Selten-Erd-Chloride vom Typ NaMCl4: Synthese und Kristallstruktur von NaLuCl4

A Structural Variant to the NaErCl₄/α-NiWO₄ Type for Ternary Rare-Earth Halides NaMCl₄: Synthesis and Crystal Structure of NaLuCl₄ Single crystals of NaLuCl₄ (orthorhombic, Pbcn (Nr. 60), Z = 4, a = 618.6(1) pm, b = 1 592.2(2) pm, c = 657.0(1) pm) were grown for the first time from the binary components using the Bridgman technique. The crystal structure may be derived from a hexagonally closest packing of Cl^? spheres with one half of all octahedral sites occupied by the cations Na⁺ and Lu³⁺, respectively. The close relation of the structure to that of NaErCl₄ (α-NiWO₄) is discussed. NaScCl₄ was found to be isotypic to NaLuCl₄.     

Ternäre Halogenide vom Typ A3MX6. VII [1]. Die Bromide Li3MBr6 (M=Sm?Lu,Y): Synthese,Kristallstruktur, Ionenbeweglichkeit

Ternary Halides of the A₃MX₆Type. VII. The Bromides Li₃MBr₆ (M=Sm? Lu, Y): Synthesis, Crystal Structure, and Ionic Mobility The bromides Li₃MBr₆ (M=Sm? Lu, Y) are obtained from the binary components LiBr and MBr₃. They crystallize with a substitution/addition variant of the AlCl_3? type of structure as was established from single crystal X-ray diffraction data for Li₃ErBr₆ (monoclinic, C2/m, Z = 2, a = 689.0(3), b = 1191.6(9), c = 684.2(6) pm, β = 109.77(6)°) and by powder X-ray diffraction for the remaining bromides. They are isotypic with Na₃GdI₆ and Li₃ScCl₆, respectively. Impedance spectroscopy and ⁷Li-NMR spectroscopy show that the lithium ions are highly mobile.     

Ternäre Halogenide vom Typ A3MX6. VI [1]. Ternäre Chloride der Selten-Erd-Elemente mit Lithium,Li3MCl6 (M  Tb?Lu,Y, Sc): Synthese,Kristallstrukturen und Ionenbewegung

Ternary Halides of the A₃MX₆ Type. VI. Ternary Chlorides of the Rare-Earth Elements with Lithium, Li₃MCl₆ (M ? Tb? Lu, Y, Sc): Synthesis, Crystal Structures, and Ionic Motion Single crystal X-ray studies on the ternary chlorides Li₃ErCl₆, Li₃YbCl₆ and Li₃ScCl₆ show that they crystallize in three different structure types. Li₃ErCl₆ (trigonal, P3 ml, Z = 3, a = 1117.7(2); c = 603.6(2) pm; the chlorides with M ? Tb? Tm, Y are isotypic) and Li₃YbCl₆ (orthorhombic, Pnma, Z = 4, a = 1286.6(1); b = 1113.2(1); c = 602.95(8) pm; Li₃LuCl₆ is isotypic) have very similar structures that may be derived from hexagonal closest packings of chloride ions with the cations occupying octahedral holes in part statistically. Li₃ScCl₆ (monoclinic, C2/m, Z = 2, a = 639.8(1); b = 1104.0(2); c = 639,1(1) pm; β = 109.89(1)°) crystallizes isotypic with Na₃GdI₆ and Li₃ErBr₆, structures that may be derived from a cubic closes packings of anions. The ionic movement in Li₃YCl₆ and Li₃YbCl₆ has been investigated by impedance and ⁷Li-NMR spectroscopy.     

Ternäre Chloride mit trigonal-bipyramidalen Clustern: [M5(C2)]Cl9 (M = La?Pr)

Ternary Chlorides with Trigonal-Bipyramidal Clusters: [M₅(C₂)]Cl₉ (M = La? Pr) The chlorides [M₅(C₂)]Cl₉ (M = La? Pr) are obtained by metallothermic reduction of the respective trichlorides MCl₃ with caesium in the presence of the lanthanide metal and carbon in sealed niobium ampoules at 800°C. They contain trigonal-bipyramidal clusters [M₅(C₂)] crystallizing with the triclinic crystal system. Only seven of the nine edges of the trigonal bipyramids are brigded by chloride (Clⁱ). Each cluster is surrounded by twelve terminal ligands (Cl^a) so that units of the composition [M₅(C₂)Cl₇ⁱ]Cl₁₂^a have to be considered. These are connected not only via Cl^i–a and Cl^a–a–a bridges. Rather, Cl^a–a (one linear and one bent) and Cl^i–i bridges are also observed.     

SrPtIn,Sr2Pt3In4, and Ca2Au3In4 – Alkaline Earth Compounds with Complex Three-Dimensional [PtIn], [Pt3In4], and [Au3In4] Polyanions

Single phase SrPtIn, Sr₂Pt₃In₄ and Ca₂Au₃In₄ were prepared by high-frequency melting of the elements in water-cooled glassy carbon crucibles. X-ray diffraction of powders and single crystals yielded Pnma, oP12, a = 758.57(9) pm, b = 451.52(6) pm, c = 846.0(2) pm, wR2 = 0.0937, 467 F² values, 20 variables for SrPtIn, P62m, hP36, a = 1465.9(2) pm, c = 448.24(6) pm, wR2 = 0.0722, 1059 F² values, 44 variables for Sr₂Pt₃In₄ and Pnma, oP36, a = 1463.6(4) pm, b = 443.23(9) pm, c = 1272.3(2) pm, wR2 = 0.0694, 1344 F² values, 56 variables for Ca₂Au₃In₄. SrPtIn adopts the TiNiSi type structure. The indium atoms have a distorted tetrahedral platinum coordination. These InPt_4/4 tetrahedra are edge- and corner-shared, forming a three-dimensional [PtIn] polyanion in which the strontium atoms are embedded. Sr₂Pt₃In₄ crystallizes with the Hf₂Co₄P₃ type structure with the more electronegative platinum atoms occupying the phosphorus sites while the indium atoms are located on the cobalt positions. Ca₂Au₃In₄ is a new site occupancy variant of the YCo₅P₃ type. Gold atoms occupy the phosphorus sites and indium the cobalt sites, but one cobalt site is occupied by calcium atoms leading to the composition Ca₂Au₃In₄. Common geometrical motifs of both structures are condensed, platinum(gold)-centered trigonal prisms formed by the alkaline earth and indium atoms. The platinum (gold) and indium atoms form complex three-dimensional [Pt₃In₄] and [Au₃In₄] polyanions, respectively. The alkaline earth cations are located in distorted hexagonal tubes.     

Ternäre Halogenide vom Typ A3MX6. IV. [1]. Ternäre Halogenide des Scandiums mit Natrium,Na3ScX6 (X = F,Cl, Br): Synthese,Strukturen, Ionenleitfähigkeit

Ternary Halides of the A₃MX₆ Type. IV. Ternary Halides of Scandium with Sodium, Na₃ScX₆ (X = F, Cl, Br): Synthesis, Structures, Ionic Conductivity X-ray studies on single crystals of Na₃ScF₆ and Na₃ScBr₆ show, that Na₃ScF₆ crystallizes with the cryolite type (monoclinic, P2₁/n, Z = 2, a = 560.16(9), b = 580.31(8), c = 812.1(2)pm, β = 90.720(14)°) and Na₃ScBr₆, as the only ternary bromide of the rare earth elements with sodium, in the Na₃CrCl₆ type (trigonal, P3 1c, Z = 2, a = 728.95(7), c = 1309.29(17)pm). The ionic conductivity of powder samples of Na₃ScF₆, Na₃ScBr₆ and of Na₃ScCl₆ was studied by impedance spectroscopy. Activation energies were determined as 1.22 eV, 0.80 eV and 0.71 eV for the fluoride, chloride and bromide, respectively. The differences are explained from the crystal structures and the sizes and polarizabilities of the anions.     

Quaternäre Caesium‐Kupfer(I)‐Lanthanoid(III)‐Selenide vom Typ CsCu3M2Se5 (M = Sm,Gd — Lu)

Quaternary Cesium Copper(I) Lanthanoid(III) Selenides of the Type CsCu₃M₂Se₅ (M = Sm, Gd — Lu) By oxidation of mixtures of copper and lanthanoid metal with elemental selenium in molar ratios of 1 : 1 : 2 and in addition of CsCl quaternary cesium copper(I) lanthanoid(III) selenides with the formula CsCu₃M₂Se₅ (M = Sm, Gd — Lu) were obtained at 750 °C within a week from torch‐sealed evacuated silica tubes. An excess of CsCl as flux helps to crystallize golden yellow or red, needle‐shaped, water‐resistant single crystals. The crystal structure of CsCu₃M₂Se₅ (M = Sm, Gd — Lu) (orthorhombic, Cmcm, Z = 4; e. g. CsCu₃Sm₂Se₅: a = 417.84(3), b = 1470.91(8), c = 1764.78(9) pm and CsCu₃Lu₂Se₅: a = 407.63(3), b = 1464.86(8), c = 1707.21(9) pm, respectively) contains [MSe₆]^9— octahedra which share edges to form double chains running along [100]. Those are further connected by vertices to generate a two‐dimensional layer parallel to (010). By edge‐ and vertex‐linking of [CuSe₄]^7— tetrahedra two crystallographically different Cu⁺ cations build up two‐dimensional puckered layers parallel to (010) as well. These sheet‐like structure interconnects the equation/tex2gif-stack-3.gif{[M₂Se₅]^4—} layers to create a three‐dimensional network according to equation/tex2gif-stack-4.gif{[Cu₃M₂Se₅]^—}. Thus empty channels along [100] form, apt to take up the Cs⁺ cations. These are surrounded by eight plus one Se^2— anions in the shape of (2+1)‐fold capped trigonal prisms with Cs—Se distances between 348 and 368 pm (8×) and 437 (for M = Sm) or 440 pm (for M = Lu), respectively, for the ninth ligand.     

Ein Beitrag Über die Verbindung CaBeNd2O5 und Phasen der Zusammensetzung M1−xM′xBeLn2O5 (M = Ca,Ba; M′ = Sr; x = 0,5)

A Contribution on the Compound CaBeNd₂O₅ and Phases of the Composition M_1?xM_x'BeLn₂O₅ (M = Ca, Ba; M′ = Sr; x = 0.5). CaBeNd₂O₅ and the phases (I): Ba_0,5Sr_0,5BeLa₂O₅ and (II): Ca_0,5Sr_0,5BeDy₂O₅ have been prepared by high temperature reactions using a CO₂-LASER. They crystallize with orthorhombic symmetry, space group D-Pnma, CaBeNd₂O₅: a = 9.448(1), b = 7.155(1), c = 6.483(1) Å; (I) a = 9.821(4), b = 7.436(3), c = 6.734(3) Å; (II): a = 9.352(2), b = 7.016(2), c = 6.375(2) Å; Z = 4, and belong to the isotypic series CaBeLn₂O₅ and SrBeLn₂O₅. Calculations of Coulomb energies of ordered BaBeLn₂O₅ and EuBeLn₂O₅ and disordered CaBeLn₂O₅, SrBeLn₂O₅ and EuBeNd₂O₅ show dependencies of the ionic radii of the M²⁺ and Ln³⁺ ions as well as of the order/disorder state.     

Synthese und Kristallstruktur von (NH4)3Cu4Ho2Br13. Weitere Bromide vom Typ (NH4)3Cu4M2Br13 (M = Dy?Lu,Y) und Rb3Cu4Ho2Br13

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)₆(Cu₄Br)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.     

Ternäre Halogenide vom Typ A3MX6. I A3YCl6 (A = K,NH4, Rb,Cs): Synthese,Strukturen, Thermisches Verhalten. Über einige analoge Chloride der Lanthanide

Ternary Halides of the A₃MX₆ Type I. A₃YCI₆ (A = K, NH₄, Rb, Cs): Synthesis, Structures, Thermal Behaviour. Some Analogous Chlorides of the Lanthanides Reaction of the trichlorides MCl₃ (M = Y, Tb? Lu) with alkali chlorides AC1 (A = K, Rb, Cs) in evacuated silica ampoules at 850?900°C yields A₃MCl₆-type chlorides. (NH₄)₃YCl₆ is obtained via the ammonium-chloride route. The crystal structure of Rb₃YCl₆ (monoclinic, C2/c (no. 15), Z = 8, a = 2583(1)pm, b = 788.9(4)pm, c = 1283.9(7)pm, p = 99.63(4)°, R = 0.062, R_w = 0.050) is that of Cs₃BiCl₆. The Rb₃YCl₆/Cs₃BiCl₆ structure and the closely related structures of K₃MoCl₆ and In₂CI₃ are derived from the elpasolite-type of structure (K₂NaAlF₆) making use of the model of closest-packed layer structures. Cell parameters for the chlorides Rb₃MCl₆ (M = Y, Tb? Lu) and Cs₃YCl₆ and Cs₃ErCl₆ as well, which are all isostructural with Rb₃YCl₆, are given. The “system” (K, NH₄, Rb, Cs)YCl₆ has been investigated by DTA and high-temperature X-ray powder diffractometry.     

Ternäre Bromide des Aluminiums,Galliums und Indiums vom Typ AIMIIIBr4 (AI = Na,Ga, K,In, Rb) Eine Übersicht

Ternary Bromides of Aluminium, Gallium, and Indium of the Formula Type A^IM^IIIBr₄ (A^I = Na, Ga, K, In, Rb). An Overview The fourteen possible bromides A^IM^IIIBr₄ with A^I = Na, Ga, K, In, Rb and M^III = Al, Ga, In are obtained from mixtures of the binary components, ABr and MBr₃. Six different structure types are observed: NaGaBr₄-, NaAlCl₄-, GaCl₂-, β-GaBr₂-, KAlBr₄-, and BaSO₄-type. Singlecrystal data are reported for the examples of NaGaBr₄, KGaBr₄, and InGaBr₄. Without exception, slightly distorted tetrahedra [MBr₄]^? occur. The structural variety must be sought in the adjustment of the coordinational needs of the counter cations A⁺ (coordination numbers between six and twelve).     

Über Neue Oxoruthenate vom Typ der 6 L-Perowskite: Ba3SrRu2−xTaxO9 (x = 0,8 und 1,4) mit einem Beitrag über Ba3CaRu2O9

On Novel Oxoruthenates of the 6 L-Perovskite Type: Ba₃SrRu_2?xTa_xO₉ (x = 0.8 and 1.4) with a Comment on Ba₃CaRu₂O₉ Single crystals of the phases Ba₃SrRu_2?xTa_xO₉ [(I): x = 0.8 and (II): x = 1.4] and the compound (III): Ba₃CaRu₂O₉ were prepared by a BaCl₂ flux and investigated by X-ray methods. (I)–(III) crystallizes with hexagonal symmetry space group P6 2c with lattice constants: (I) a = 6.003 Å; c = 15.227 Å; (II) a = 5.988 Å; c = 15.220 Å and (III) a = 5.891 Å; c = 14.571 Å. The crystal structures of these substances corresponds to the 6 layer perovskites with the stacking sequence (hcc)₂. All of them show a so far not described slightly distorted oxygen framework caused by the Sr²⁺ and Ca²⁺ ions.     

Ternäre Acetate der Lanthanide mit Caesium: Dimere und Trimere in CsLu(CH3COO)4 bzw. Cs2[Lu3(CH3COO)10(OH)(H2O)]. Synthese,Kristallstrukturen und Thermolyse

Ternary Acetates of the Lanthanides with Cesium: Dimers in CsLu(CH₃COO)₄ and Trimers in Cs₂[Lu₃(CH₃COO)₁₀(OH)(H₂O)]. Synthesis, Crystal Structures, Thermolysis Single crystals of CsLu(CH₃COO)₄ and Cs₂[Lu₃(CH₃COO)₁₀(OH)(H₂O)] were obtained from an aqueous solution of lutetium and cesium acetate in a 1:1 molar ratio. The crystal structures (CsLu(CH₃COO)₄: monoclinic, P2₁/n (no. 14), Z = 8, a = 1 293.1(2), b = 1 323.8(2), c = 1 622.5(3) pm, β = 92.01(2)°, V_m = 208.97(6) cm³/mol, R = 0.056, R_w = 0.034; Cs₂[Lu₃(CH₃COO)₁₀(OH)(H₂O)]: monoclinic, C2/c (no.15), Z = 4, a = 2 138.5(6), b = 1 378.0(3), C = 1 482.9(4) pm, β = 106.15(2)°, V_m = 632.0(3) cm³/mol, R = 0.049, R_w = 0.036) were determined from four-circle-diffractometer data. The structures consist of dimers and trimers, respectively, that are built by bridging acetate groups. These units are fragments of the infinite chains of the Ho(CH₃COO)₃ type of structure. The isotypic compounds CsM(CH₃COO)₄ with M=Eu? Lu were synthesized and characterized by the X-ray Guinier technique. The thermal decomposition of CsLu(CH₃COO)₄ was examined with thermoanalytical methods (TG/DSC with coupled gas analysis) and the Guinier-Simon technique: it decomposes at 260°C in an endothermic reaction to Lu₂O₃ and Cs₂CO₃.     

Synthese und Kristallstrukturen von (3‐Methylpyridinium)3[DyCl6] und (3‐Methylpyridinium)2[DyCl5(Ethanol)]

Preparation and Structure of (3‐Methylpyridinium)₃[DyCl₆] and (3‐Methylpyridinium)₂[DyCl₅(Ethanol)] The complex chlorides (3‐Methylpyridinium)₃[DyCl₆] ( 1 ) and (3‐Methylpyridinium)₂[DyCl₅(Ethanol)] ( 2 ) have been prepared for the first time. The crystal structures have been determined from single crystal X‐ray diffraction data. 1 crystallizes in the trigonal space group R3c (Z = 36) with a = 2953.3(3) pm, b = 2953.3(3) pm and c = 3252.5(4) pm, compound 2 crystallizes in the triclinic space group P1 (Z = 2) with a = 704.03(8) pm, b = 808.10(8) pm, c = 1937.0(2) pm, α = 77.94(1)°, β = 87.54(1)° and γ = 83.26(1)°. The structures contain isolated octahedral building units [DyCl₆]^3– and [DyCl₅(Ethanol)]^2–, respectively.     

Ternäre Halogenide vom Typ A3MX6. III [1, 2]. Synthese,Strukturen und Ionenleitfähigkeit der Halogenide Na3MX6 (X = Cl,Br)

Ternary Halides of the A₃MX₆ Type. III [1, 2]. Synthesis, Structures, and Ionic Conductivity of the Halides Na₃MX₆ (X = Cl, Br) The bromides Na₃MBr₆ crystallize with the stuffed LiSbF₆-type structure (type I; M = Sm? Gd) or with the structure of the mineral cryolite (type II; M = Gd? Lu). The structure types were refined from single crystal X-ray data (Na₃SmBr₆: trigonal, space group R3 , a = 740.8(2) pm, c = 1 998.9(8) pm, Z = 3; Na₃YBr₆: monoclinic, space group P2₁/n, a = 721.3(4) pm, b = 769.9(2) pm, c = 1 074.8(4) pm, β = 90.60(4)°, Z = 2). Reversible phase transitions from one structure to the other occur. The phase transition temperatures were determined for the bromides as well as for the chlorides Na₃MCl₆ (M = Eu? Lu). The refinement of both structures for one compound was possible for Na₃GdBr₆ (I: trigonal, space group R3 , a = 737.1(5) pm, c = 1 887(2) pm, Z = 3; II: monoclinic, space group P2₁/n, a = 725.2(1) pm, b = 774.1(3) pm, c = 1 080.1(3) pm, β = 90.76(3)°, Z = 2). All compounds exhibit ionic conductivity of the sodium ions which decreases with the change from type I to type II. The conductivity of the bromides is always higher when compared with the respective chlorides.     

Ternäre Thalliumplatin- und Thalliumpalladiumchalkogenide Tl2M4X6. Synthesen,Kristallstruktur und Bindungsverhältnisse

Ternary Thallium Platinum and Thallium Palladium Chalcogenides Tl₂M₄X₆. Syntheses, Crystal Structures, and Bonding Relations The compounds Tl₂Pt₄S₆, Tl₂Pt₄Se₆, Tl₂Pt₄Te₆ and Tl₂Pd₄Se₆ can be synthesized by a melting reaction from the elements or by the reaction of thallium carbonate, transition metal powder and chalcogen powder in the temperature range between 400°C and 950°C. X-Ray investigations on single crystals and powdered samples revealed a new structure type for the compounds, that can be understood as stacking variant of the already known atom arrangement of the alkaline metal platinum chalkogenides A₂Pt₄X₆ (A ? alkaline metal, X ? S, Se). The short distances thallium-platinum and thallium-palladium, respectively, as well as the results of Extended-Hückel-calculations indicate covalent bonds between the main group and transition metal atoms.     

Nd4N2Se3 und Tb4N2Se3: Zwei nicht‐isotype Lanthanoid(III)‐Nitridselenide

Nd₄N₂Se₃ and Tb₄N₂Se₃: Two non‐isotypical Lanthanide(III) Nitride Selenides The non‐isotypical nitride selenides M₄N₂Se₃ of neodymium (Nd₄N₂Se₃) and terbium (Tb₄N₂Se₃) are formed by the reaction of the respective rare‐earth metal with sodium azide (NaN₃), selenium and the corresponding rare‐earth tribromide (MBr₃) at 900 °C in evacuated silica ampoules after seven days. Each of them crystallizes monoclinically in the space group C2/c with Z = 4 for Nd₄N₂Se₃ (a = 1300.47(4), b = 1009.90(3), c = 643.33(2) pm, β = 90.039(2)°) and in the space group C2/m with Z = 2 for Tb₄N₂Se₃ (a = 1333.56(5), b = 394.30(2), c = 1034.37(4) pm, β = 130.377(2)°), respectively. The crystal structures differ fundamentally in the linkage of the structure dominating N^3‐ centred (M³⁺)₄ tetrahedra. In Nd₄N₂Se₃, the [NNd₄] units are edge‐linked to bitetrahedra which are cross‐connected to [N(Nd1)(Nd2)]³⁺ layers via their remaining four corners, whereas the [NTb₄] tetrahedra in Tb₄N₂Se₃ share cis‐oriented edges to form strands [N(Tb1)(Tb2)]³⁺. Both structures contain two crystallographically different M³⁺ cations, that show coordination numbers of six and seven (Nd₄N₂Se₃) or twice six (Tb₄N₂Se₃), respectively, relative to the anions (N^3‐ und Se^2‐). Each of the two independent kinds of Se^2‐ anions provide the three‐dimensional linkage as well as the charge balance. The particular axial ratio a/c and the monoclinic reflex angle offer two choices for fixing the unit cell of Tb₄N₂Se₃.     

Drei Alkalimetall‐Erbium‐Thiophosphate: Von der Schichtstruktur bei KEr[P2S7] zur dreidimensionalen Vernetzung in NaEr[P2S6] und Cs3Er5[PS4]6

Three Alkali‐Metal Erbium Thiophosphates: From the Layered Structure of KEr[P₂S₇] to the Three‐Dimensional Cross‐Linkage in NaEr[P₂S₆] and Cs₃Er₅[PS₄]₆ The three alkali‐metal erbium thiophosphates NaEr[P₂S₆], KEr[P₂S₇], and Cs₃Er₅[PS₄] show a small selection of the broad variety of thiophosphate units: from ortho‐thiophosphate [PS₄]^3? and pyro‐thiophosphate [S₃P–S–PS₃]^4? with phosphorus in the oxidation state +V to the [S₃P–PS₃]^3? anion with a phosphorus‐phosphorus bond (d(P–P) = 221 pm) and tetravalent phosphorus. In spite of all differences, a whole string of structural communities can be shown, in particular for coordination and three‐dimensional linkage as well as for the phosphorus‐sulfur distances (d(P–S) = 200 – 213 pm). So all three compounds exhibit eightfold coordinated Er³⁺ cations and comparably high‐coordinated alkali‐metal cations (CN(Na⁺) = 8, CN(K⁺) = 9+1, and CN(Cs⁺) ≈ 10). NaEr[P₂S₆] crystallizes triclinically ( ; a = 685.72(5), b = 707.86(5), c = 910.98(7) pm, α = 87.423(4), β = 87.635(4), γ = 88.157(4)°; Z = 2) in the shape of rods, as well as monoclinic KEr[P₂S₇] (P2₁/c; a = 950.48(7), b = 1223.06(9), c = 894.21(6) pm, β = 90.132(4)°; Z = 4). The crystal structure of Cs₃Er₅[PS₄] can also be described monoclinically (C2/c; a = 1597.74(11), b = 1295.03(9), c = 2065.26(15) pm, β = 103.278(4)°; Z = 4), but it emerges as irregular bricks. All crystals show the common pale pink colour typical for transparent erbium(III) compounds.