Darstellung und Kristallstruktur von Rb2Sn3S7 · 2H2O und Rb4Sn2Se6

Preparation and Crystal Structure of Rb₂Sn₃S₇ · 2 H₂O and Rb₄Sn₂Se₆ Rb₂Sn₃S₇ · 2 H₂O has been prepared by hydrothermal reaction of SnS₂ and Rb₂CO₃ in an with H₂S saturated aqueous solution at 190°C. The crystal lattice contains chain anions [Sn₃S₇^2?] which display both SnS₄ tetrahedra and SnS₆ octahedra. Methanolothermal reaction of SnCl₂ with Se and Rb₂CO₃ at 145°C leads to the formation of Rb₄Sn₂Se₆ which contains edge-bridged bitetrahedral [Sn₂Se₆]^4? anions.     

[Cu3(S4)3]−, ein neues kondensiertes anorganisches Ringsystem Strukturvergleich mit anderen Polysulfido-Clustern des Kupfers

[Cu₃(S₄)₃]^3?, a New Condensed Inorganic Ring System. Comparison with the Structures of Other Polysulfido Clusters of Copper By reaction of Cu(CH₃COO)₂ · H₂O with a polysulfide solution [(C₆H₅)₄P]₂(NH₄)-[Cu₃(S₄)₃] · 2CH₃OH ( 1a ) could be obtained in a pure form. The anion [Cu₃(S₄)₃]^3? ( 1 ) consists of a central Cu₃S₃ ring and three CuS₄ rings. An X-ray structure analysis yields the following results for 1a : Space group P2₁/c, a = 2317.4(7), b = 1458.4(4), C = 1843. 1(5) pm, β = 108.68(2)°, V = 5901.0 10⁶ pm³, Z = 4; R = 0.101 for 3817 independent reflections (Fo > 3.92° (Fo)). 1a was also characterized by its Raman spectrum.     

(PPh4)[(ReO2S2)CuI] und (NEt4)2[(ReOS3)Cu3Cl4]: Fixierung der bisher nicht isolierten Ionen [ReO2S2]− und [ReOS3]− durch Ausnutzung der Stabilität der CuS2(Re)- und Cu3S3(Re)-Fragmente

(PPh₄)[(ReO₂S₂)CuI] and (NEt₄)₂[ReOS₃)Cu₃Cl₄]: Fixation of the up to now not Isolated Ions [ReO₂S₂]^? and [ReOS₃]^? Utilizing the Stability of the CuS₂(Re) and Cu₃S₃(Re) Fragments (PPh₄)[(ReO₂S₂)CuI] ( 1 ) and (NEt₄)₂[ReOS₃)Cu₃Cl₄] ( 2 ) containing the up to now not isolated oxothioperrhenate ions [ReO₂S₂]^? and [ReOS₃]^? as ligands, have been prepared by the reaction of (NEt₄)[ReS₄] with PPh₃ and CuI in acetone in the presence of (PPh₄)I (( 1 )) or with CuCl in CH₂Cl₂ in the presence of (NEt₄)Cl (( 2 )), respectively. 1 and 2 have been characterized by X-ray structure analysis, elemental analysis and spectroscopic studies (IR, UV/Vis). The electronic spectra show bands which can approximately be assigned to interesting low-energy charge-transfer-transitions of the type d(Cu) → d(Re). For crystal data see Inhaltsübersicht.     

Diskrete polynukleare Metall-Komplexe aus Polysulfid-Lösungen: [Cu6S17]2−, ein ungewöhnlicher binärer CuI-Komplex mit verschiedenen bemerkenswerten strukturellen Eigenschaften

Discrete Polynuclear Metal Complexes from Polysulfide Solutions: [Cu₆S₁₇]^2?, a Novel Binary Polynuclear Cu^I Complex with Several Remarkable Structural Features The complex [Cu₆S₁₇]^2?, obtained from Cu(acac)₂ and an ethanolic polysulfide solution, contains an unusual arrangement of the metal atoms and novel types of ligand coordination, particularly of polysulfido (S₄^2? and S₅^2?) ions. The relevance of the synthesis with respect to the “dilemma of transporting metals together with sulfur” for the process of metal sulfide rock formation is evidenced. (PPh₄)₂[Cu₆S₁₇] crystallizes in the space group C2/c with Z = 4 (for further details see Inhaltsübersicht).     

Reaktionen von Zinnchloriden mit Polysulfiden. Die Kristallstrukturen von (PPh4)2[SnCl2(S6)2], (PPh4)2[Sn4Cl4S5(S3)O] und (PPh4)2[SnCl6] · S8 · 2CH3CN

Reaction of Tin Chlorides with Polysulfides. Crystal Structures of (PPh₄)₂[SnCl₂(S₆)₂], (PPh₄)₂[Sn₄Cl₄S₅(S₃)O], and (PPh₄)₂[SnCl₆] · S₈ · 2CH₃CN . The reaction of PPh₄[SnCl₃] with Na₂S₄ in acetonitrile in the presence of small amounts of water yields (PPh₄)₂[Sn₄Cl₄S₅(S₃)O] and minor amounts of (PPh₄)₂[SnCl₂(S₆)₂], PPh₄Cl · 2S₈ and (PPh₄)₂[SnCl₆]. SnCl₄ is partially reduced by (PPh₄)₂S_x, PPh₄[SnCl₃] and (PPh₄)₂[SnCl₆] · S₈ · 2CH₃CN being produced. According to the X-ray crystal structure determination the [Sn₄Cl₄S₅(S₃)O]^2?-ion consists of an O atom that is coordinated by four Sn atoms which in turn are liked with one another by five single S atoms and one S₃ group. In the [SnCl₂(S₆)₂]^2?-ion the Sn atom is octahedrally coordinated by two Cl atoms in trans arrangement and by two chelating S₆ groups. Octahedral [SnCl₆]^2? ions and S₈ molecules in the crown conformation are present in (PPh₄)₄[SnCl₆] · S₈ · 2CH₃CN.     

Darstellung und Schwingungsspektren der Komplexe [MBr6]−, [Br5MN3]− und [Br5MNPPh3]− von Niob und Tantal Die Kristallstruktur von PPh4[NbBr6]

Preparation and vibrational spectra of the complexes [MBr₆]^?, [Br₅MN₃]^? and [Br₅MNPPh₃]^? of niobium and tantalum. Cyrstal structure of PPh₄[NbBr₆] The compounds PPh₄[MBr₆] and PPh₄[MBr₅N₃] are obtained by reaction of MBr₅ with PPh₄Br or PPh₄N₃, respectively, in CH₂Cl₂ solution (M ? Nb, Ta). The azido complexes PPh₄[MBr₅N₃] can also be obtained by reactions of the hexabromo complexes with iodine azide. According to its i.r. spectrum the symmetry of the [MBr₆]^? ion is lower than O_h in the solide state. This is corfirmed for PPh₄[NbBr₆] by a crystal structure analysis; it crystallizes in the monoclinic space group B2/b with four formula units in the unit cell and with the lattice constants a = 2301, b = 1777, c = 686 pm and γ = 96,6°. The structure was determined with X-ray diffraction data and was refined to a residual index of R = 0.055. The [NbBr₆]^? ion has the symmetry C_i, the deviations from O_h being small. In the azido complexes [MBr₅N₃]^? the azido groups are covalently linked with the metal. From [NbBr₅N₃]^? and PPh₃ the complex [Br₅Nb?N?PPh₃]^?, is obtained; for the analogous formation of the corresponding Ta complex photochemical activation is necessary. In this way the complex [Cl₅Nb?N?AsPh₃]^? can also be obtained. I.r. spectra of all the compounds are reported and assigned.     

K2NdP2S7: A Mixed‐Valent Neodymium(III) Thiophosphate According to K4Nd2[PS4]2[P2S6] with Discrete [PS4]3– and [S3P–PS3]4– Anions

Pale blue, lath‐shaped single crystals of K₂NdP₂S₇ (≡ K₄Nd₂[PS₄]₂[P₂S₆]; monoclinic, P2₁/n, a = 904.76(8), b = 677.38(6), c = 1988.7(2) pm, β = 97.295(5)°, Z = 2) are obtained by the reaction of Nd, S and P₂S₅ with an excess of KCl as a flux in evacuated silica tubes at 750 °C (7 d) which should produce Nd[PS₄] instead. Beside isolated [PS₄]^3– tetrahedra, the crystal structure contains discrete ethane‐analogous [P₂S₆]^4– (≡ [S₃P–PS₃]^4–) units in staggered conformation with tetravalent phosphorus cations and a P–P distance of 219 pm. The two crystallographically different potassium cations show coordination numbers of nine and ten in the shape of distorted mono‐ and bicapped square antiprisms. Finally, the Nd³⁺ cations are surrounded by eight sulfur atoms arranged as (uncapped) square antiprisms. The entire structure is dominated by (K1)⁺ containing {(Nd₂[PS₄]₂[P₂S₆])^4–} layers parallel (101) which are three‐dimensionally interconnected by (K2)⁺ cations.     

Sm4S3[Si2O7] und NaSm9S2[SiO4]6: Zwei Sulfidsilicate mit dreiwertigem Samarium

Sm₄S₃[Si₂O₇] and NaSm₉S₂[SiO₄]₆: Two Sulfide Silicates with Trivalent Samarium The sulfide silicates Sm₄S₃[Si₂O₇] and NaSm₉S₂[SiO₄]₆ are obtained as light yellow transparent crystals by the reaction of Sm, Sm₂O₃, S, and SiO₂ with fluxing SmCl₃ or NaCl, respectively, in suitable molar ratios in fused evacuated silica tubes (850 °C, 7 d). Tetragonal crystals of Sm₄S₃[Si₂O₇] (I4₁/amd; Z = 8; a = 1186.4(1); c = 1387.0(2) pm) with ecliptically conformed [Si₂O₇]^6–‐groups of corner sharing [SiO₄]‐tetrahedra are formed. These double tetrahedra as well the sulfide anions (S^2–) coordinate two crystallographically independent metal cations. They provide coordination numbers of 8 + 1 (5 S^2– and 3 + 1 O^2–) for Sm1 and 9 (3 S^2– and 6 O^2–) for Sm2. NaSm₉S₂[SiO₄]₆ crystallizes hexagonally (P6₃/m; Z = 1; a = 975.32(9); c = 676.46(7) pm) in a modified bromapatite‐type structure. The coordination spheres about the two crystallographically different Sm³⁺ cations are built up by oxygen atoms of the orthosilicate units ([SiO₄]^4–) and sulfide anions (S^2–). As a result, Sm1 and Sm2 have coordination numbers of 9 and 8, respectively. Na⁺ and (Sm1)³⁺ occupy the position 4 f in a molar ratio of 1 : 3 whereas the lower coordinated (Sm2)³⁺ occupies the 6 h position.     

Ionic‐Radius‐Driven Selection of the Main‐Group‐Metal Cage for Intermetalloid Clusters [Ln@PbxBi14−x]q− and [Ln@PbyBi13−y]q− (x/q=7/4, 6/3; y/q=4/4, 3/3)

Reactions of the binary, pseudo‐homoatomic Zintl anion (Pb₂Bi₂)^2? with Ln(C₅Me₄H)₃ (Ln=La, Ce, Nd, Gd, Sm, Tb) in the presence of [2.2.2]crypt in ethane‐1,2‐diamine/toluene yielded ten [K([2.2.2]crypt)]⁺ salts of lanthanide‐doped semimetal clusters with 13 or 14 surface atoms. Single‐crystal X‐ray diffraction and energy‐dispersive X‐ray spectroscopy indicated the presence of the anions [Ln@Pb₆Bi₈]^3?, [Ln@Pb₃Bi₁₀]^3?, [Ln@Pb₇Bi₇]^4?, or [Ln@Pb₄Bi₉]^4? in single or double salts; the latter showed various ratios of the components in the solid state. The anions are the first ternary intermetalloid clusters comprising only elements of the sixth period of the periodic table, namely, Pb, Bi and lanthanides. This study, which was complemented by ESI mass spectrometry and ¹³⁹La NMR spectroscopy in solution, rationalizes a continuous development of the ratio of 13:14‐atom cages with the ionic radius of the embedded Ln³⁺ ion, which seems to select the most suitable cage type. Quantum chemical investigations helped to analyze this situation in more detail and to explain the observed subtle influence of the atomic radii. Magnetic measurements confirmed that the embedded Ln³⁺ ions keep their expected paramagnetic or diamagnetic nature.     

Chalkogenohalogenogallate(III) und -indate(III): Eine neue Verbindungsklasse in der dritten Hauptgruppe. Synthese und Struktur von [Ph4P]2[In2SX6], [Et4N]3[In3E3Cl6] · MeCN und [Et4N]3[Ga3S3Cl6] · THF (X = Cl,Br; E = S,Se)

Chalcogenohalogenogallates(III) and -indates(III): A New Class of Compounds for Elements of the Third Main Group. Preparation and Structure of [Ph₄P]₂[In₂SX₆], [Et₄N]₃[In₃E₃Cl₆] · MeCN and [Et₄N]₃[Ga₃S₃Cl₆] · THF (X = Cl, Br; E = S, Se) [In₂SCl₆]^2?, [In₂SBr₆]^2?, [In₃S₃Cl₆]^3?, [In₃Se₃Cl₆]^3?, and [Ga₃S₃Cl₆]^3? were synthesised as the first known chalcogenohalogeno anions of main group 3 elements. [Ph₄P]₂[In₂SCl₆] ( 1 ) (P1 ; a = 10.876(4) Å, b = 12.711(6) Å, c = 19.634(7) Å, α = 107.21(3)°, β = 96.80(3)°, γ = 109.78(3)°; Z = 2) and [Ph₄P]₂[In₂SBr₆] ( 2 ) (C2/c; a = 48.290(9) Å, b = 11.974(4) Å, c = 17.188(5) Å, β = 93.57(3)°, Z = 8) were prepared by reaction of InX₃, (CH₃)₃SiSSi(CH₃)₃ and Ph₄PX (X = Cl, Br) in acetonitrile. The reaction of MCl₃ (M = Ga, In) with Et₄NSH/Et₄NSeH in acetonitrile gave [Et₄N]₃[In₃S₃Cl₆] · MeCN ( 3 ) (P2₁/c; a = 17.328(4) Å, b = 12.694(3) Å, c = 21.409(4) Å, β = 112.18(1)°, Z = 4), [Et₄N]₃[In₃Se₃Cl₆] · MeCN ( 4 ) (P2₁/c; a = 17.460(4) Å, b = 12.816(2) Å, c = 21.513(4) Å, β = 112.16(2)°, Z = 4), and [Et₄N]₃[Ga₃S₃Cl₆] · THF ( 5 ) (P2₁/n; a = 11.967(3) Å, b = 23.404(9) Å, c = 16.260(3) Å, β = 90.75(2)°, Z = 4). The [In₂SX₆]^2? anions (X = Cl, Br) in 1 and 2 consist of two InSX₃ tetrahedra sharing a common sulfur atom. The frameworks of 3, 4 and 5 each contain a six-membered ring of alternating metal and chalcogen atoms. Two terminal chlorine atoms complete a distorted tetrahedral coordination sphere around each metal atom.     

The Neat Ternary Solid K5−xCo1−xSn9 with Endohedral [Co@Sn9]5− Cluster Units: A Precursor for Soluble Intermetalloid [Co2@Sn17]5− Clusters

A new type of Zintl phase is presented that contains endohedrally filled clusters and that allows for the formation of intermetalloid clusters in solution by a one‐step synthesis. The intermetallic compound K_5?xCo_1?xSn₉ was obtained by the reaction of a preformed Co? Sn alloy with potassium and tin at high temperatures. The diamagnetic saltlike ternary phase contains discrete [Co@Sn₉]^5? clusters that are separated by K⁺ ions. The intermetallic compound K_5?xCo_1?xSn₉ readily and incongruently dissolves in ethylenediamine and in the presence of 4,7,13,16,21,24‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacosane (2.2.2‐crypt), thereby leading to the formation of crystalline [K([2.2.2]crypt)]₅[Co₂Sn₁₇]. The novel polyanion [Co₂Sn₁₇]^5? contains two Co‐filled Sn₉ clusters that share one vertex. Both compounds were characterized by single‐crystal X‐ray structure analysis. The diamagnetism of K_5?xCo_1?xSn₉ and the paramagnetism of [K([2.2.2]crypt)]₅[Co₂Sn₁₇] have been confirmed by superconducting quantum interference device (SQUID) and EPR measurements, respectively. Quantum chemical calculations reveal an endohedral Co^1? atom in an [Sn₉]^4? nido cluster for [Co@Sn₉]^5? and confirm the stability of the paramagnetic [Co₂Sn₁₇]^5? unit.     

A New Solvothermal Synthetic Route Yields the New Thio­stannate [La(dien)3]2[Sn2S6]Cl2

Applying a new synthesis protocol with cystamine dihydrochloride as sulfur source we were able to synthesize the new compound [La(dien)₃]₂[Sn₂S₆]Cl₂ ( 1 ) (dien = diethylenetriamine) under solvothermal conditions. Under these conditions the S–S bond of the cystamine molecule is cleaved generating the S^2– anions. The title compound is formed via an intermediate, (dienH)₂Sn₃S₇, which reacts to the final product at longer reaction times. The structure crystallizes in the monoclinic space group P2₁/n and is composed of two ninefold coordinated [La(dien)₃]³⁺complexes, one [Sn₂S₆]^4– anion, and two Cl^– anions. The Hirshfeld surface analysis reveals a large number of intermolecular interactions including S ··· H and Cl ··· H bonding.     

Darstellung und Kristallstruktur von Ethylendiammonium-Selenostannaten(IV) sowie von [2 SnSe2 · en]∞

Preparation and Crystal Structure of Ethylenediammonium Selenostannates(IV) and [2 SnSe₂ · en]∞ The selenostannates(IV) [enH₂]₂[Sn₂Se₆] · en 1 and [enH₂][Sn₃Se₇] · 1/2en 2 have been prepared by the methanolothermal reaction of SnSe₂ with ethylenediamine (en) (160°C, 13 bar) in the presence of respectively Se or BaSe. The [Sn₂Se₆]^4? anion in 1 consists of two edgebridged SnSe₄ tetrahedra and displays crystallographic C_i symmetry. The crystal structure of 2 contains polyselenostannate(IV) sheet anions [Sn₂Se₇²], for which the basic elements are trigonal SnSe₅ bipyramids. Each of the three symmetry independent Sn atoms is linked to the other Sn atoms via Sn? Se? Sn bridges leading to the formation of Sn₃Se₁₀ units. Methanolothermal reaction of SnSe₂ with en alone yields the edge-bridged chain structure [2 SnSe₂ en]∞ 3 , in which each of the Sn atoms is bonded to four Se atoms. Every second Sn atom is also coordinated by an en molecule and displays, therefore, an octahedral geometry. The remaining Sn atoms are coordinated tetrahedrally by Se atoms.     

Step‐by‐Step Synthesis of the Endohedral Stannaspherene [Ir@Sn12]3− via the Capped Cluster Anion [Sn9Ir(cod)]3−

The endohedral stannaspherene cluster anion [Ir@Sn₁₂]^3? was synthesized in two steps. The reaction of K₄Sn₉ with [IrCl(cod)]₂ (cod: 1,5‐cyclooctadienyl) in ethylenediamine (en) solution first yielded the [K(2,2,2‐crypt)]⁺ salt (2,2,2‐crypt: 4,7,13,16,21,24‐hexaoxa‐1,10‐diazabicyclo[8.8.8]hexacosane) of the capped cluster anion [Sn₉Ir(cod)]^3?. Subsequently, crystals of this compound were dissolved in en, followed by the addition of triphenylphosphine or 1,2‐bis(diphenylphosphino)ethane and treatment at elevated temperatures. [Ir@Sn₁₂]^3? was obtained and characterized as the [K(2,2,2‐crypt)]⁺ salt. The isolation of [Sn₉Ir(cod)]^3? as an intermediate product establishes that the formation of the stannaspherene [Ir@Sn₁₂]^3? occurs through the oxidation of [Sn₉Ir(cod)]^3?. Among the structurally characterized tetrel cluster anions, [Ir@Sn₁₂]^3? is a unique example of a stannaspherene, and one of the rare spherical clusters encapsulating a metal atom that is not a member of Group 10. Single‐crystal structure determination shows that the novel Zintl ion cluster has nearly perfect icosahedral I_h point symmetry.     

NaAg3S2, ein Thioargentat mit dem Clusteranion [Ag6S4]2−

NaAg₃S₂, a Thioargentate Containing the Anionic Cluster [Ag₆S₄]^2? . Dark-red octahedrally shaped crystals of NaAg₃S₂ could be obtained by the reaction of NaAg(CN)₂ and NaCN in a stream of hydrogen sulfide at 630 K. NaAg₃S₂ crystallizes cubic, a=12.358(1) Å, space group Fd3 m, Z=16. The structure was determined from four-circle diffractometer data. NaAg₃S₂ contains the anionic cluster [Ag₆S₄]^2?. The structure can be traced back to the spinel structure typ. An extended Hückel calculation for the cluster anion, which is considered to be isolated, shows weak bonding silver-silver interactions. NaAg₃S₂ is diamagnetic at room temperature.     

Syntheses,Crystal Structures,and Reactivity of [enH]4[Sn2Se6]·en, [enH]4[Sn2Te6]·en and [enH]4[Sn2S6]: Known Anions within Novel Coordination Spheres obtained by Novel Synthesis Routes

The hexachalcogenodistannates K₆[Sn^III₂Se₆] or Li₄[Sn^IV₂Te₆]·8en were recently reported to simultaneously act as mild oxidants and chalcogenide sources in reactions with CoCl₂/LiCp* (Cp* = pentamethylcyclopentadienide) while the Sn—E (E = Se, Te) fragment is not kept in the products, e.g. [(Cp*Co)₃(μ₃‐Se)₂], [(Cp*Co)₃(μ₃‐Se)₂][Cl₂Co(μ₂‐Cl)₂Li(thf)₂] or [(Cp*Co)₄(μ₃‐Te)₄]. In search of related reagents with possibly different reaction behavior, we isolated and crystallographically characterized isotypic compounds [enH]₄[Sn^IV₂Se₆]�en ( 1 ), and [enH]₄[Sn^IV₂Te₆]·en ( 2 ) (en = 1, 2‐diaminoethane), that result from an uncommon disproportion/re‐arrangement reaction: distannate(III) K₆[Sn₂E₆] (E = Se, Te) was reacted with en·2HCl to yield 1 or 2 under disproportion of Sn^III to Sn^II and Sn^IV. Another pathway was necessary to synthesize the respective but solvent‐free thiostannate [enH]₄ [Sn^IV₂S₆] ( 3 ), since the phase “K₆[Sn₂S₆]” is unknown. This second method started out from SnCl₄·2THF and S(SiMe₃)₂ in en solution. However, using E(SiMe₃)₂ (E = Se, Te) instead of S(SiMe₃)₂, 1 and 2 are also obtained this way. 1—3 are the first chalcogenostannates that exhibit exclusively [enH]⁺ counterions. The compounds were characterized by means of X‐ray crystallography and NMR spectroscopy. They seem to be suitable for reactions towards group 8‐10 metal complexes. Preliminary experiments indicate that the binary anions 1 — 3 coordinated by 1‐aminoethylammonium ions react more slowly compared to the anionic phases tested until now.     

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.     

Syntheses, structures, physical properties, and electronic structures of KLn2CuS4 (Ln=Y, Nd, Sm, Tb, Ho) and K2Ln4Cu4S9 (Ln=Dy, Ho)

Seven new quaternary metal sulfides, KY₂CuS₄, KNd₂CuS₄, KSm₂CuS₄, KTb₂CuS₄, KHo₂CuS₄, K₂Dy₄Cu₄S₉, and K₂Ho₄Cu₄S₉, were prepared by the reactive flux method. All crystallographic data were collected at 153 K. The isostructural compounds KLn₂CuS₄ (Ln=Y, Nd, Sm, Tb, Ho) crystallize in space group Cmcm of the orthorhombic system with four formula units in cells of dimensions (Ln, a, b, c (Å)): Y, 3.9475(9), 13.345(3), 13.668(3); Nd, 4.0577(3), 13.7442(10), 13.9265(10); Sm, 4.0218(4), 13.6074(14), 13.8264(14); Tb, 3.9679(5), 13.4243(17), 13.7102(18); Ho, 3.9378(3), 13.3330(11), 13.6487(11). The corresponding R₁ indices for the refined structures are 0.0197, 0.0153, 0.0158, 0.0181, and 0.0178. The isostructural compounds K₂Dy₄Cu₄S₉ and K₂Ho₄Cu₄S₉ crystallize in space group C2/m of the monoclinic system with two formula units in cells of dimensions (Ln, a, b, c (Å), β (°)): Dy, 13.7061(13), 3.9482(4), 15.8111(15), 109.723(1); Ho, 13.6760(14), 3.9360(4), 15.7950 (16), 109.666(2). The corresponding R₁ indices are 0.0312 and 0.0207. Both structure types are closely related three-dimensional tunnel structures. The tunnels are filled with bicapped trigonal-prismatically coordinated K atoms. Their anionic frameworks are built from LnS₆ octahedra and CuS₄ tetrahedra. KLn₂CuS₄ contains _∞¹[CuS₃⁵⁻] chains of vertex-sharing tetrahedra and K₂Ln₄Cu₄S₉ contains _∞¹[Cu₄S₈¹²⁻] chains of tetrahedra. K₂Ho₄Cu₄S₉ shows Curie-Weiss paramagnetic behavior between 5 and 300 K, and has an effective magnetic moment of 10.71 μ_B for Ho³⁺ at 293 K. Optical band gaps of 2.17 eV for KSm₂CuS₄ and 2.43 eV for K₂Ho₄Cu₄S₉ were deduced from diffuse reflectance spectra. A first-principles calculation of the density of states and the frequency-dependent optical conductivity was performed on KSm₂CuS₄. The calculated band gap of 2.1 eV is in good agreement with the experimental value.     

Stabilization of Highly Reactive “Naked Anions”: Synthesis,Crystal Structure and Vibrational Spectrum of [Na(12‐crown‐4)2]2 [P2S6] · CH3CN

The novel thiodiphosphate, [Na(12‐crown‐4)₂]₂[P₂S₆] · CH₃CN, bis[di(12‐crown‐4)sodium] hexathiodiphosphate(V) acetonitrile solvate ( 1 ) has been synthesized by the reaction of Na₂[P₂S₆] with 12‐crown‐4 in dry acetonitrile. The title compound crystallizes in the tetragonal space group P4₂/mbc (no. 135), with a = 15.184(1) Å, c = 21.406(2) Å and Z = 4 and final R1 = 0.0671 and wR2 = 0.0809. The crystal structure is characterized by discrete sodium‐bound crown‐ether sandwich cations, [Na(12‐crown‐4)₂]⁺ and [P₂S₆]^2? ions with D_2h symmetry. Sodium ion is coordinated by the eight oxygen atoms of two crown‐ether molecules to form a square antiprisma. Solvent molecules of CH₃CN are statistically disordered. Distances and angles of the [P₂S₆]^2? unit are similar to those in [K(18‐crown‐6)]₂ [P₂S₆] · 2 CH₃CN, and in K₂[P₂S₆] and Cs₂[P₂S₆]. The FT‐Raman and FT‐IR spectrum of the title compound has been recorded and interpreted, especially with respect to the P₂S₆ group and in comparison to the few known metal hexathiodiphosphates(V).