Beiträge zur Chemie des Phosphors. 231. Li3P7S3 und Li2HP7S2 — die ersten Sulfido-heptaphosphane(3)

Contributions to the Chemistry of Phosphorus. 231. Li₃P₇S₃ and Li₂HP₇S₂ — the First Sulfido Heptaphosphanes(3) The novel sulfido heptaphosphanes(3) Li₃P₇S₃ ( 1 ) and Li₂HP₇S₂ ( 2 ) have been obtained by the reaction of Li₃P₇ with sulfur in tetrahydrofuran under suitable conditions. The compounds 1 and 2 are also formed from LiP₅ and sulfur and are only stable in solution below room temperature. According to a complete analysis of the ³¹P{¹H}-NMR spectra, in each case, the sulfur atoms are bonded as sulfido groups exocyclically to the heptaphosphanortricyclene skeleton. Compound 2 reacts with chloro(trimethyl)silane or acetylacetone at one of the two sulfido groups while compound 1 does not form any product with retention of the P₇(3) framework.     

Beiträge zur Chemie des Phosphors. 157. Dilithium-hexadecaphosphid,Li2P16: Darstellung aus Li2HP7 und 31P-NMR-spektroskopische Strukturbestimmung

Contributions to the Chemistry of Phosphorus. 157. Dilithium Hexadecaphosphide, Li₂P₁₆: Preparation from Li₂HP₇ and Structure Determination by ³¹P-NMR Spectroscopy . Dilithium hexadecaphosphide, Li₂P₁₆ ( 1 ), is purely obtained as a crystalline solvent adduct Li₂P₁₆ · 8 THF by the disproportionation of Li₂HP₇ in tetrahydrofuran under suitable conditions. The constitution of 1 has been deduced from its 1D- and 2D-³¹P-NMR spectrum (in dimethylformamide). The structure of the P₁₆^2? ion in solution is identical with that in solid (Ph₄P)₂P₁₆ [20]. As a conjuncto-phosphane the P₁₆^2? is made up of two P₉(3)^?-unit groups analogous to deltacyclane, which are linked via the diatomic bridges as a common zero-bridge.     

Beiträge zur Chemie des Phosphors. 140. Dilithium-hydrogenheptaphosphid,Li2HP7 – ein teilmetalliertes Derivat von P7H3: Darstellung und strukturelle Charakterisierung

Contributions to the Chemistry of Phosphorus. 140. Dilithium Hydrogen Heptaphosphide, Li₂HP₇ — a Partially Metallated Derivative of P₇H₃: Preparation and Structural. Characterization Dilithium hydrogen heptaphosphide, Li₂HP₇ ( 2 ), is purely obtained as an orange-red solvent adduct by reacting P₂H₄ with n-BuLi or Li₃P₇ ( 1 ) under suitable conditions. 2 is also formed in the metalation of LiH₂P₇ ( 3 ) or P₇H₃, in the disproportionation of LiH₄P₅, in thepartial protolysis of 1 , and in the nucleophilic cleavage of P₄. The composition and the structure of 2 could be elucidated by a complete analysis of its low-temperature ³¹P{¹H}-NMR spectrum. As shown by the δ(³¹P) values, the P₇ cage in 2 is clearly distorted compared with 1 . The P₇H^2? ion has fluctuating bonds in analogy to dihydrobullvalene and can be described by two valence-tautomeric forms with identical structures. At room temperature 2 disproportionates yielding lithium polyphosphides with a greater number of phosphorus atoms.     

Electrochemical insertion of lithium into the ramsdellite-type oxide Li2Ti3O7: influence of the Li2Ti3O7 particle size

The effect of a milling process on the electrochemical performance of Li₂Ti₃O₇ electrodes has been investigated by the galvanostatic intermittent titration technique (GITT) and AC impedance spectroscopy. The insertion ratio is slightly increased by the milling treatment and a value of x _Li=1.25 per mol Li₂Ti₃O₇ has been determined. The average potential during insertion is close to 1.5 V/Li. The analysis of impedance data obtained at equilibrium during insertion and deinsertion shows two relaxation processes and a diffusion phenomenon at low frequency according to the Frumkin-Melik-Gayakazian model. Cycling experiments of batteries using this material were performed with unmilled and milled particles. Composite electrodes containing different amounts of electroactive material added to a binder and a conductive additive have also been prepared in order to check the effect of grinding on the cyclability of the compound. Interesting electrochemical performances have been determined with such electrodes: lithium uptake up to 1.25 Li per Li₂Ti₃O₇, low irreversible capacity loss between the first and the following cycles, good stability upon cycling even after 50 cycles. However, the milled process has not improved significantly the electrochemical performance of the Li₂Ti₃O₇ electrodes. Electronic Publication     

Beiträge zur Chemie des Phosphors. 227. HP4º als Komplexligand: Bildung und Eigenschaften von [(η5-C5H5)2ZrCl(P4H)], [(η5-C5Me5)2ZrCl(P4H)] und [(η5-C5H5)3Zr(P4H)]

Contributions to the Chemistry of Phosphorus. 227. HP₄º as a Complex Ligand: Formation and Properties of [(η⁵-C₅H₅)₂ZrCl(P₄H)], [(η⁵-C₅Me₅)₂ZrCl(P₄H)], and [(η⁵-C₅H₅)₃Zr(P₄H)] The novel complexes [(η⁵-C₅H₅)₂ZrCl(P₄H)] ( 1 ), [(η⁵-C₅Me₅)₂ZrCl(P₄H)] ( 2 ), and [(η⁵-C₅H₅)₃Zr(P₄H)] ( 3 ) have been obtained by reaction of a solution of (Na/K)HP₄ with the zirconocen derivatives [(η⁵-C₅H₅)₂ZrCl₂], [(η⁵-C₅Me₅)₂ZrCl₂], and [(η⁵-C₅H₅)₃(η¹-C₅ H₅)Zr] under suitable conditions. The structure of the compounds 1 – 3 , which are only stable in solution, has been elucidated by means of ³¹P-NMR spectroscopy. It is highly probable that the exo,endo isomer exists in each case. In addition, further isomers of lower relative abundancies have been observed, in which the ligands presumably exhibit a different spatial orientation relatively to each other.     

Further Examples of the P‐O‐P Connection in Borophosphates: Synthesis and Characterization of Li2Cs2B2P4O15, LiK2BP2O8, and Li3M2BP4O14 (M=K,Rb)

A new series of anhydrous mixed alkali‐metal borophosphates—Li₂Cs₂B₂P₄O₁₅ ( 1 ), LiK₂BP₂O₈ ( 2 ), Li₃K₂BP₄O₁₄ ( 3 ), and Li₃Rb₂BP₄O₁₄ ( 4 )—have been successfully synthesized by using the conventional solid‐state reaction method. Compound 1 contains a novel fundamental building unit (FBU), [B₄P₈O₃₀], with B/P=1:2. Compound 2 contains an FBU of [B₂P₄O₁₆] with B/P=1:2. Compounds 3 and 4 are isotypic, and they have a [B(P₂O₇)₂] unit as their FBU. In all four compounds, their FBUs are connected through corner sharing to generate layered anionic partial structures, and then further linked with metallic polyhedra to form three‐dimensional (3D) frameworks. Most interestingly, three of the four compounds contain direct P‐O‐P connections in their structures, which is extremely rare among borophosphates. Thermal analyses, IR spectroscopy, and UV/Vis/near‐IR diffuse reflectance spectroscopy have also been performed on the four title compounds.     

Thermal Analysis of the System Li2WO4-Li4P2O7-WO3

The system Li₂WO₄-Li₄P₂O₇-WO₃ in the range of WO₃ contents of up to 60 mol % was studied by thermal analysis. In the examined range of the composition triangle, the crystallization fields of lithium tungstate and pyrophosphate, of congruently melting compound D (Li₂WO₄·WO₃), and of incongruently melting compound D ₂ (2Li₂WO₄·Li₄P₂O₇) were revealed, and the glass formation region was established. Low-melting compositions showing promise for synthesis of lithium-tungsten oxide bronzes were revealed.     

Neue Oxoterbate(IV) mit Lithium Rb2Li14[Tb3O14] und Li6Tb2O7

New Oxoterbates(IV) with Lithium: On Rb₂Li₁₄[Tb₃O₁₄] and Li₆Tb₂O₇ For the first time we prepared Rb₂Li₁₄[Tb₃O₁₄] as yellow single crystals from Li₈TbO₆ and Rb₂O (Tb:Rb = 1:2) [Ag-cylinder, 500°C, 30 d, then Au-tube, 700°C, 27 d]. The structure refinement [652 I₀ (h kl), four circle diffractometer Philips PW 1100, ω-scan, MoKα, R = 4.69%, R_w = 3.24%, absorption considered, Immm with a = 1 283.07(10), b = 790.87(7), c = 736.87(7)pm, Z = 2, d_x = 4.30 g · cm^?3] confirms that it is isotypic with K₂Li₁₄[Pb₃O₁₄]. Furthermore we got for the first time Li₆Tb₂O₇ as a bright yellow compound from Li₂O₂ and “Tb₄O₇*” [(Li:Tb = 3.4:1), Au-ube, 750°C, 13 d (powder), 850°C 22 d (single crystals)] and by thermal decomposition of Rb₂Li₁₄[Tb₃O₁₄] (Au-tube, 850°C, 25 d). Powder and single crystal data [1 327 I₀ (h kl), four circle diffractometer PW 1100, ω-scan, AgKα, R = 9.38%, R_w = 5.23%, absorption not considered, P2₁/a, a = 1 056.30(10), b = 613.50(4), c = 546.56(5) pm, β = 109.668(7)°, Z = 2, d_x = 4.67 g · cm^?3 d_pyc = 4.53 g · cm^?3] reveal a new type of structure that may be deduced by the NaCl-type of structure. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Beiträge zur Chemie des Phosphors. 221 [1]. Stannylsubstituierte Bicyclo [1.1.0]tetraphosphane: Bildung und Eigenschaften von R3Sn(H)P4 (R  CH3, C6H5, c-C6H11, o-C7H7)

Contributions to the Chemistry of Phosphorus. 221. Stannyl-Substituted Bicyclo[1.1.0]tetraphosphanes: Formation and properties of R₃Sn(H)P₄ (R ? CH₃, C₆H₅, c-C₆H₁₁, o-C₇H₇) The unsymmetrically substituted bicyclo[1.1.0]tetraphosphanes Me₃Sn(H)P₄ ( 1 ), Ph₃Sn(H)P₄ ( 2 ), (c-Hex)₃Sn(H)P₄ ( 3 ) and (o-Tol)₃Sn(H)P₄ ( 4 ) have been obtained by reaction of a solution of (Na/K) HP₄ with R₃ SnCl (R ? Me, Ph, c-Hex, o-Tol) under proper conditions. The structure of the compounds 1 – 4 , which are only stable in solution, has been elucidated by means of ³¹P-NMR-spectroscopy. Whereas 3 exists at ?60°C as the exo,endo isomer, 1, 2 and 4 are fluctuating molecules at room temperature and probably invert between the three possible configurational isomers (exo,exo-, exo,endo- and endo,endo-form).     

Beiträge zur Chemie des Phosphors. 226. 2,3,4,6-Tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphan,P6BuO2

Contributions to the Chemistry of Phosphorus. 226. 2,3,4,6-Tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphane, P₆Bu O₂ Under suitable conditions, the reaction of tetra-tert-butylhexaphosphane, P₆Bu ( 1 ), with cumene hydroperoxide gives rise to the corresponding dioxide P₆BuO₂ ( 3 ) which could be isolated as the adduct P₆BuO₂ · 0.7 C₉H₁₂O₂. According to a complete analysis of the ³¹P{¹H}-NMR spectrum compound 3 is 2,3,4,6-tetra-tert-butyl-2,4-dioxobicyclo[3.1.0]hexaphosphane, in which the oxygen atoms are bonded exocyclically to the five-membered phosphorus ring of 1 . When the oxidation reaction proceeds a fission of the bicyclic P₆ skeleton takes place.     

Raman and infrared spectra of6Li2C2O4 and7Li2C2O4

Raman and infrared spectra of polycrystalline⁶Li₂C₂O₄ and⁷Li₂C₂O₄ have been investigated in the wavenumber region from 1,800 to 40 cm^–1. The internal C₂O₄ ^–2 vibrations have been studied on the basis of a D_2h molecular structure and the correlation field splittings have been found to be about 40 cm^–1 for the stretching modes and about 15 cm^–1 for the bending modes. The external vibrations of the Li⁺ and C₂O₄ ^–2 sites have been discussed by considering the results of the factor group analysis and the⁶Li/⁷Li isotope effect on the normal vibrations.

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Raman- und Infrarot-Spektren von⁶Li₂C₂O₄ und⁷Li₂C₂O₄

Zusammenfassung Es wurdenRaman- und IR-Spektren von polykristallinem⁶Li₂C₂O₄ und⁷Li₂C₂O₄ im Bereich der Wellenzahlen von 1800 bis 40 cm^–1 untersucht. Die internen Schwingungen wurden auf der Basis einer D_2h Molekülstruktur analysiert. Für die Streckschwingungen wurde eine Korrelationsaufspaltung von etwa 40 cm^–1 gefunden, für die Deformationsschwingungen etwa 15 cm^–1. Die Diskussion der externen Schwingungen von Li⁺ und C₂O₄ ^–2 erfolgte unter Berücksichtigung der Resultate der Faktorgruppenanalyse und des⁶Li/⁷Li Isotopeneffekts auf die Normalschwingungen.

     

Darstellung und Kristallstruktur der Verbindung Li4H2Si2O7

Zusammenfassung Die Verbindung Li₄H₂Si₂O₇ wird durch Umsetzung von Li₆Si₂O₇ mit Methanol bzw. Wasserdampf dargestellt und ihre Kristallstruktur an Hand von Einkristallaufnahmen bestimmt. Die tetragonale Elementarzelle ( ) mita=7,59₅ undc=5,06 Å enthält zwei Formeleinheiten. Die Verbindung zählt zu den Sorosilicaten, mit [Si₂O₇]-Gruppen, die gleich angeordnet sind wie in Li₆Si₂O₇. Im Gegensatz zu Li₆Si₂O₇, das die Lithiumatome teils in einer vierzähligen Lage (KZ=5) teils einer achtzähligen Lage (KZ=4) enthält, ist in der Verbindung Li₄H₂Si₂O₇ nur letztere Position mit Lithiumatonen besetzt. Die Verteilung der Wasserstoffatome wird diskutiert.

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Preparation and crystal structure of the compoundLi ₄H₂Si₂O₇

The compound Li₄H₂Si₂O₇ has been prepared by reaction of Li₆Si₂O₇ with methanol and water vapour, resp. The crystal structure has been determined by single-crystal data. The tetragonal cell ( ):a=7.59₅ andc=5.06 Å contains two formula units. The compound belongs to the soro-silicates the [Si₂O₇]-groups being arranged analogous to Li₆Si₂O₇. In contrast to Li₆Si₂O₇, containing the lithium atoms both in a 4-fold position (c.n.=5) and an 8-fold position (c.n.=4), in the compound Li₄H₂Si₂O₇ only the latter is occupied by lithium atoms. The distribution of the hydrogen atoms is discussed.

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Mit 1 Abbildung     

KZn(HP2O7)·2H2O and KMn(HP2O7)·2H2O: acid pyrophosphate metallates(II) with layer structures

The crystal structures of the isomorphous title compounds, namely potassium zinc hydrogen pyrophosphate dihydrate and potassium manganese hydrogen pyrophosphate dihydrate, consist of acidic pyrophosphate–metallate(II) layers joined by K⁺ ions and hydrogen‐bridging bonds. The Zn²⁺/Mn²⁺ ions are octahedrally surrounded by four pyrophosphate O atoms and by two water mol­ecules. The (HP₂O₇)^3? anions exhibit eclipsed conformations. The metal ions and water O atoms lie on mirror planes, as does the central O atom of the (HP₂O₇)^3? anion.     

Further Example of Diphosphates: Synthesis and Characterization of K2Li2P2O7

By the application of cation substitution, a new mixed‐alkali metal diphosphate, K₂Li₂P₂O₇, was successfully synthesized through high temperature solution method for the first time. The single‐crystal X‐ray structural analysis shows that it crystallizes in the monoclinic space group C2/c (no. 15), with lattice constants a = 9.814(3) Å, b = 5.5163(15) Å, c = 13.538(4) Å, Z = 4, and β = 110.47(2)°. Its open cage‐like _∞³[Li₂(P₂O₇)]^2– framework is built up from alternating arrangement of Li₂O₆ and P₂O₇ dimers that form eight and twelve‐membered‐ring channels along the [010] direction, and the K atoms are entrapped in the larger twelve‐membered‐ring channels. Detailed structure comparisons in the N₄P₂O₇ (N = mixed alkali metals) family are discussed. In addition, the structural validity was verified through the IR spectrum. Thermal analyses and UV/Vis/NIR diffuse reflectance spectrum are also performed on the reported compound.     

KHCoP2O7·2H2O: a novel acidic pyrophosphate

Potassium cobalt hydrogenpyrophosphate dihydrate, KHCoP₂O₇·2H₂O, crystallizes in the orthorhombic space group Pnma. This salt is isotypic with KHMP₂O₇·2H₂O (M = Mn and Zn). The structure consists of alternating layers, built from HP₂O₇³⁻ acidic pyrophosphate groups and CoO₆ octahedra, joined by potassium ions and bridging hydrogen bonds. The Co, K and water O atoms lie on mirror planes. The pyrophosphate group consists of two symmetry‐related PO₄ groups, with the bridging O atom on a mirror plane.     

Zur Kenntnis ‘Kationen-reicher’ Tantalate Über Li7[TaO6]

On Tantalates ‘rich in Cations’ On Li₇[TaO₆] For the first time, colourless single crystals of Li₇[TaO₆] were grown by annealing intimate mixtures of Li₂O and Ta₂O₅ (Li:Ta = 7,7:1) in closed Ni-cylinders (1 000°C, 156 d). [Trigonal-rhomboedral with a = 535.8(1) pm, c = 1 507.3(3) pm, c/a = 2.81/Guinier-Simon-powder data; Z = 3. Space group R3 for the part Li(1)₆TaO₆ and presumably P3 for Li₇TaO₆, including Li(2)]. The crystal structure was solved by four-cycle-diffractometer data [Mo? Kα , 331 from 331 I_o(hkl), R = 1.99%, R_w = 1.96%], parameters see text. The positions of anions correspond to the motif of a hexagonal closest packing of spheres, obviously deformed (with MEFIR of O^2? space filling corresponds to 69.8% instead of expected 73.2%. 1/3 of the octahedron holes are ordered occupied by Ta and Li(2), 1/2 of the tetrahedral holes likewise ordered by Li(1). All polyhedra of coordination of the anions are trigonal prisms. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, as well as charge distribution ‘CHARDI’ are calculated and discussed.     

Water-rich molybdotellurates: Preparation and crystal structure of Li6[TeMo6O24] · 18 H2O and Li6[TeMo6O24] · Te(OH)6 · 18 H2O

Li₆[TeMo₆O₂₄] · 18 H₂O is triclinic (space group P1 , a = 1 041.7(1), b = 1 058.6(1), c = 1 070.8(1) pm, α = 61.08(1), β = 60.44(1), γ = 73.95(1)°). Single crystal X-ray structure analysis (Z = 1, 295 K, 317 parameters, 3 973 reflections, R_g = 0.0250) revealed an infinite branched chain of edge-sharing Li coordination polyhedra to be the prominent structural feature. One of the four crystallographically independent Li⁺ is coordinated octahedrally. The coordination polyhedra of the remaining Li⁺ are distorted trigonal bipyramids. Only three unique oxygen atoms (O(9), O(10), O(12)) of the centrosymmetric [TeMo₆O₂₄]^6? anion are bound to Li⁺. The further positions in the coordination spheres of the Li⁺ are occupied by water molecules. Intermolecular hydrogen bonds involve mainly oxygen atoms of the [TeMo₆O₂₄]^6? anion as nearly equivalent proton acceptors without regard to their different bonding modes to Te and Mo, respectively. Li₆[TeMo₆O₂₄] · Te(OH)₆ · 18 H₂O crystallizes monoclinically in space group P2₁/n with Z = 4, a = 994.1(3), b = 2 344.8(10), c = 1 764.9(4) pm, and β = 91.36(4)°. Single crystal structure analysis with least squares refinement of 627 parameters (5 900 reflections, 295 K) converged to R_g = 0.0324. There are six unique Li⁺ cations. The coordination polyhedra of Li(1), Li(2), Li(3), and Li(4) are linked by common edges to yield an eight membered centrosymmetric strand. The coordination polyhedra of the remaining two Li⁺ sites (Li(5), Li(6)) are connected to a dimeric unit via a common corner. All oxygen atoms of the Te(OH)₆ molecule are involved in the coordination of Li⁺. However, only three oxygen atoms (O(13), O(18), O(23)) of the [TeMo₆O₂₄]^6? anion which lacks crystallographic symmetry are involved in the coordination of Li⁺. The oxygen atoms of the anion act as proton acceptors in hydrogen bonds of predominantly medium strength. Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions connected by strong hydrogen bonds form an infinite chain.     

(Mg1–xCrx)2P2O7, CaCrP2O7, SrCrP2O7 und BaCrP2O7 – Neue Diphosphate des zweiwertigen Chroms

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXI. (Mg_1–xCr_x)₂P₂O₇, CaCrP₂O₇, SrCrP₂O₇ and BaCrP₂O₇ – New Diphosphates of Divalent Chromium In the quasi‐binary systems A₂P₂O₇/Cr₂P₂O₇ (A = Mg, Ca, Sr, Ba) the solid solution (Mg_1–xCr_x)₂P₂O₇ as well as the new compounds CaCrP₂O₇, SrCrP₂O₇, and BaCrP₂O₇ have been synthesized and characterized for the first time. In the whole experimental range (0.01 < x < 0.94; T = 950 °C) the solid solution (Mg_1–xCr_x)₂P₂O₇ is isotypic to the pure phases β‐Mg₂P₂O₇ and β‐Cr₂P₂O₇; but no phase transition (β → α) to a low‐temperature modification, as in Mg₂P₂O₇ and Cr₂P₂O₇, was found. CaCrP₂O₇ ( A ), SrCrP₂O₇ ( B ), and BaCrP₂O₇ ( C ), phases without detectable homogenity range in the other quasi‐binary systems are not structurally related to each other, but are isotypic to the corresponding compounds containing cobalt. [( A ): P‐1, Z = 2, a = 6.312(2) Å, b = 6.499(2) Å, c = 6.916(2) Å, α = 83.12(3)°, β = 88.37(3)°, γ = 67.72(3)°, 3235 independent reflections, R1 = 0.041, wR2 = 0.112; ( C ): P‐1, Z = 2, a = 5.382(8) Å, b = 7.271(8) Å, c = 7.589(4) Å, α = 103.33(7)°, β = 89.91(9)°, γ = 93.6(1)°, 1571 independent reflections, R1 = 0.085, wR2 = 0.31]. We have reported earlier details on SrCrP₂O₇. The coordination of Cr²⁺ by oxygen is distorted octahedral in ( A) , while in the structures of ( B) and ( C) square‐pyramidal environment is found. The results of UV/VIS‐spectroscopic and magnetic measurements as well as IR‐spectra of the diphosphates are reported.     

Zur Chemie und Strukturchemie von Phosphiden und Polyphosphiden. 42. Trilithiumheptaphosphid Li3P7: Darstellung,Struktur und Eigenschaften

Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 42. Trilithiumheptaphosphide Li₃P₇: Preparation, Structure, and Properties Trilithium heptaphosphide, Li₃P₇, has been prepared by reaction of the elements at 870 K in Nb and Ta ampoules, respectively. The bright yellow (solventfree) substance crystallizes in a new structure type (P2₁2₁2₁; a = 974.2(1) pm; b = 1053,5(1) pm; c = 759,6(1) pm; Z = 4). The structure is closely related to the plastically crystalline Rb₃P₇ type of structure (Li₃Bi variant). The heptaphosphanortricyclene anions P₇^3? are surrounded by 12 Li cations and connected one to each other in a complex manner. The anion exhibits a differentation of distances and angles typical for ionic nortricyclenes X₇^3? (P? P distances: d?(basis) = 224.9 pm; d?(basis-bridge) = 214.7 pm; d?(bridge-bridgehead) = 217.6 pm). The distances Li to P are in the range of 250 ≤ d(Li? (2b)P^?) ≤ 270 pm. The P? P and Li? P bond distances are equivalent to meaningful Pauling bond orders PBO. On heating in closed ampoules, Li₃P₇ shows an endothermic effect at 900 K, corresponding to a first order phase transition into a HT phase of unknown nature up to now. On thermal decomposition no congruent dissociative sublimation occurs in contrast to the other heptaphosphides M₃P₇, but LiP and Li₃P are formed, the latter evaporates congruently dissociative, Solutions of Li₃P₇ in en show valence fluctuation of the P₇^3? anions already at room temperature (δ ³¹P-NMR = ? 122.1). Further reactions of Li₃P₇ are reported as well as the structural differences between Li₃P₇ and the solvates Li₃P_7solv3 are discussed.     

Über quaternäre Oxoplumbate(IV). Zur Kenntnis von Rb2Li14[Pb3O14] und Cs2Li14[Pb3O14]

On Quaternary Oxoplumbates(IV). On the Knowledge of Rb₂Li₁₄[Pb₃O₁₄] and Cs₂Li₁₄[Pb₃O₁₄] For the first time, Rb₂Li₁₄[Pb₃O₁₄] and Cs₂Li₁₄[Pb₃O₁₄] have been prepared by heating of mixtures of Li₂O, β-?PbO₂”? and Rb₂PbO₃, Cs₂PbO₃ respectively with Li:Pb:A = 14:3:2, (A = Rb, Cs). [Ag-cylinders, sealed under vacuum in Duran-glass ampoule, 590 and 550°C, 40 d, powder (650°C, 200 d, single crystals of Rb₂Li₁₄[Pb₃O₁₄])]. Rb₂Li₁₄[Pb₃O₁₄] is nearly colourless with ivory nuance, Cs₂Li₁₄[Pb₃O₁₄] is pale yellow. According to powder and single crystal investigations, both are isotypic with K₂Li₁₄[Pb₃O₁₄]. Structure refinement of Rb₂Li₁₄[Pb₃O₁₄]: 1015 symmetry independent reflexions, four-circle-diffraktometer PW 1100 (Fa. Philips), ω-scan, MoKα, R = 5.73%, R_W = 5.33%, absorption not considered, space group Immm with a = 1284.71(9), b = 793.90(4), c = 727,35(5) pm, d_x-ray = 4.99 g · cm^?3, d_pyc = 5.01 g · cm^?3, Z = 2. Cs₂Li₁₄[Pb₃O₁₄]: a = 1295.28(12), b = 796.69(8), c = 732.44(7) pm, d_x-ray = 5.31 g · cm^?3, d_pyc = 5.28 g · cm^?3, Z = 2. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated.