Kristallstruktur von Hexamincyclotriphosphazen,P3N3(NH2)6

Crystal Structure of Hexamine Cyclotriphosphazene, P₃N₃(NH₂)₆ In the presence of KNH₂ hexamine cyclotriphosphazene semi ammoniate (molar ratio 12:1) in NH₃ gives crystals of solvent free P₃N₃(NH₂)₆ within 5 d at 130°C and p(NH₃) = 110 bar. The structure was solved by X-rax methods: P₃N₃(NH₂)₆: P2₁/c, Z = 4, a = 10.889(6) Å, b = 5.9531(6) Å, c = 13.744(8) Å, β = 97.83(3)°, Z(F_o) = 1 721 with (F_o)² ≥ 3σ(F_o)², Z(var.) = 157, R/R_w = 0,036/0,041 The structure contains columns of molecules P₃N₃(NH₂)₆ all in the same orientation. The six-membered rings within one molecule have boat conformation. The columns are stacked together in a way that one is surrounded by four others shifted by half a lattice constant in direction [010]. Strong hydrogen bridge-bonds N? H…?N connect molecules within the columns and between them.     

Rb2I(OH): Ein Hydroxidiodid im System RbOH/RbI

Rb₂I(OH): A Hydroxide Iodide in the System RbOH/RbI The pseudobinary system RbOH/RbI was investigated by X-ray methods. The crystal structure of Rb₂I(OH) was solved by single crystal data: Rb₂I(OH): Pnma, Z = 4, a = 7.748(1) Å, b = 5.654(2) Å,c = 13.254(2) Å Z(F_o) with (F_o)² ? 3σ = (F_o)² = 449, Z (parameter) = 25, R/R_w = 0.021/0.023 Rb₂I(OH) crystallizes in a new type of structure, built up by a three dimensional network of [Rb₂(OH)⁺] containing the iodide ions.     

K2Br(OH) und Rb2Br(OH): Zwei neue ternäre Alkalimetallhalogenidhydroxide mit ausgeprägter Strukturverwandtschaft zu KOH bzw. RbOH

K₂Br(OH) and Rb₂Br(OH): Two New Ternary Alkali Metal Halide Hydroxides with a Pronounced Structural Relationship to KOH resp. RbOH Two isotypic compounds K₂Br(OH) and Rb₂Br(OH) were prepared in the systems KOH/KBr and RbOH/RbBr. Their structures were determined by single crystal X-ray methods: K₂Br(OH): P2₁/m, Z = 2, a = 6.724(1) Å, b = 4.272(4) Å, c = 8.442(2) Å, β = 108.14(2)°, Z(F_o) = 651 with (F_o)² ≥ 3σ(F_o)², Z(parameter) = 28, R/R_w = 0.041/0.047 Rb₂Br(OH): P2₁/m, Z = 2, a = 6.918(3) Å, b = 4.483(2) Å, c = 8.850(5) Å, β = 108.08(6)°, Z(F_o) = 326 mit (F_o)² ≥ 3σ(F_o)², Z(parameter) = 27, R/R_w = 0.074/0.082. The compounds are built up by chains of [M₂(OH)⁺] connected via Br^?. The structure of the chains as well as their orientation to one another show a pronounced relationship to the structures of the room temperature modifications of the isotypic binary hydroxides KOH and RbOH.     

Zur Kenntnis von Na4Br(NH2)3: Ein Amidbromid im System NaNH2/NaBr

Na₄Br(NH₂)₃: An Amide Bromide in the System NaNH₂/NaBr The pseudobinary system NaNH₂/NaBr was investigated by X-ray methods. The crystal structure of Na₄Br(NH₂)₃ was solved by single crystal data: Pnnm, Z = 4, a = 6.579(2) Å, b = 12.755(4) Å, c = 8.776(2) Å Z(F_o) with (F_o)² ≥ 3σ = (F_o)² = 503, Z(parameter) = 39, R/R_w = 0.082/0.106. It is a new type of structure, built up by a three-dimensional network of [Na₄(NH₂)₃⁺] containing the bromide ions.     

Synthese und Kristallstruktur von Mangan(II)‐ und Zinkamid,Mn(NH2)2 und Zn(NH2)2

Synthesis and Crystal Structure of Manganese(II) and Zinc Amides, Mn(NH₂)₂ and Zn(NH₂)₂ Metal powders of manganese resp. zinc react with supercritical ammonia in autoclaves in the presence of a mineralizer Na₂Mn(NH₂)₄ resp. Na₂Zn(NH₂)₄_.0.5NH₃ to well crystallized ruby‐red Mn(NH₂)₂ (p(NH₃) = 100 bar, T = 130°C, 10 d) resp. colourless Zn(NH₂)₂ (p(NH₃) = 3.8 kbar, T = 250°C, 60 d). The structures including all H‐positions were solved by x‐ray single crystal data: Mn(NH₂)₂: I4₁/acd, Z = 32, a = 10.185(6) Å, c = 20.349(7) Å, N(F_o) with F > 3σ (F) = 313, N(parameter) = 45, R/R_w = 0.038/0.043. Zn(NH₂)₂: I4₁/acd, Z = 32, a = 9.973(3) Å, c = 19.644(5) Å, N(F_o) with F > 3σ (F) = 489, N(parameter) = 45, R/R_w = 0.038/0.043. Both compounds crystallize isotypic with Mg(NH₂)₂ [1] resp. Be(NH₂)₂ [2]. Nitrogen of the amide ions is distorted cubic close packed. One quarter of tetrahedral voids is occupied by Mn²⁺‐ resp. Zn²⁺‐ions in such an ordered way that units M₄(NH₂)₆(NH₂)_4/2 occur. The H‐atoms of the anions have such an orientation that the distance to neighboured cations is optimum.     

Li2Br(NH2): Das erste ternäre Alkalimetallamidhalogenid

Li₂Br(NH₂): The First Ternary Alkali Metal Amide Halide The pseudobinary system LiNH₂/LiBr was investigated by X-ray methods. The crystal structure of the compound Li₂Br(NH₂) was solved by single crystal data: Li₂Br(NH₂): Pnma, Z = 8, a = 12.484(2) Å, b = 7.959(1) Å, c = 6.385(1) Å, Z(F_o) with (F_o)² ≧ 3σ(F_o)² = 348, Z (parameter) = 51, R/R_w = 0.019/0.021 Li₂Br(NH₂) crystallizes in a new type of structure. To one another isolated chains of [Li₂Li_4/2(NH₂)₂²⁺] show the motif of closest rod packing. They are connected via bromide ions in a distorted cubic primitive arrangement.     

Rubidiumhexaamidolanthanat und -neodymat,Rb3[La(NH2)6] und Rb3[Nd(NH2)6]; Strukturverwandtschaft zu K3[Cr(OH6)] und K4CdCl6

Rubidium Hexaamidolanthanate and -neodymate, Rb₃[La(NH₂)₆] and Rb₃[Nd(NH₂)₆]; Compounds. Structurally Related to K₃[Cr(OH)₆] and K₄CdCl₆ Colourless Rb₃[La(NH₂)₆] (a = 12.298(4) Å, c = 13.759(2) Å, N = 6, R3 c) and pale blue Rb₃[Nd(NH₂)₆] (a = 12.199(6) Å, c = 13.626(4) Å, N = 6, R32) have been prepared by the reaction of the corresponding metals (Rb: La resp. Nd = 3:1) with NH₃(P(NH₃) = 4–4.5 kbar) at 300°C. Single crystal x-ray methods gave their structures. It is shown by space group relations that these compounds are structurally related to one another and to further ternary amides as well as to K₃[Cr(OH)₆] and K₄CdCl₆.     

Hexamincyclotriphosphazenhemiammoniakat,P3N3(NH2)6 · 0,5 NH3, ein Produkt der Hochdruckammonolyse von weißem Phosphor

Hexaminecyclotriphosphazenehemiammoniate, P₃N₃(NH₂)₆ · 0.5 NH₃, a Product of High Pressure Ammonolysis of White Phosphorus White phosphorus gives at NH₃-pressures ≥5 kbar and temperatures above 250°C in a disproportionation reaction P₃N₃(NH₂)₆ · 0.5 NH₃; besides these products red phosphorus is formed. The yield on P₃N₃(NH₂)₆ · 0.5 NH₃ increases with T and is about 70–80% at 400°C as to the disproportionation reaction of the amount of white phosphorus. X-ray structure determination was successful on single crystals of P₃N₃(NH₂)₆ · 0.5 NH₃. Pbca, N = 8 a = 11.395(3) Å, b = 12.935(4) Å, c = 12.834(4) Å R = 0.035, R_w = 0.041 with w = 1, N (F_o²) ≥ 3σ(F_o²) = 1371, N(Var.) = 166. The molecules are connected by N? H? N-bridgebonds with 3.04 Å ≤ d(N …? N) ≤ 3,19 Å and d (N? H) = 0.87 Å. The compound is furthermore characterized by IR-data and its thermical behaviour.     

Beiträge zum thermischen Verhalten wasserfreier Phosphate. IX. Darstellung und Kristallstruktur von Cr6(P2O7)4. Ein gemischtvalentes Pyrophosphat mit zwei- und dreiwertigem Chrom

Contributions on the Thermal Behaviour of Anhydrous Phosphates. IX. Synthesis and Crystal Structure of Cr₆(P₂O₇)₄. A Pyrophosphate Containing Di- and Trivalent Chromium Cr₆(P₂O₇)₄ (Cr₂²⁺Cr₄³⁺(P₂O₇)₄) can be obtained reducing CrPO₄ by phosphorus (950°C, 48 h, 100 mg iodine as mineralizer). By means of chemical transport reactions (transport agent iodine; 1050 → 950°C) the compound has been separated from its neighbour phases (Cr₂P₂O₇, CrP₃O₉) and crystallized (greenish, transparent crystals; edge length up to 0.3 mm). The crystal structure of Cr₆(P₂O₇)₄ (Spcgrp.: P-1; z = 1; a = 4.7128(8) Å, b = 12.667(3) Å, c = 7.843(2) Å, α = 89.65(2)°, β = 92.02(2)°, γ = 90.37(2) has been solved and refined from single crystal data (2713 unique reflections, 194 parameter, R = 0.035). Cr²⁺ is surrounded by six oxygen atoms which occupy the corners of an elongated octahedron (4 × d^{Cr? O} ≈? 2.04 Å; 2 × d^{Cr? O} ≈? 2.62 Å). The Cr³⁺ ions are also coordinated octahedraly (1.930 Å ≤ d_{Cr? O} ≤ 2.061 Å). The crystallographically independent pyrophosphate groups show nearly eclipsed conformation. The bridging angles (P? O? P) are 136.5° and 138.9° respectively.     

Protonenlagen bei Kaliumtetraamidozinkat,K2Zn(NH2)4

Positions of the Protons in Potassium Tetraamidozincate, K₂Zn(NH₂)₄ X-ray single crystal data for K₂Zn(NH₂)₄ allowed the determination of the so far unknown positions of the protons: P1 , Z = 2, a = 6.730(1) Å, b = 7.438(1) Å, c = 8.019(2) Å, α = 72.03(2)°, β = 84.45(2)°, γ = 63.82(1)°, Z(F₀) with (F₀)² ≥ 3σ(F₀)² = 2166, Z(parameters) = 96, R/R_W = 0.032/0.039. In the structure of K₂Zn(NH₂)₂ the amide ions are nearly hexagonal close packed. One layer of octahedral holes parallel to (010) is fully occupied by potassium atoms and zinc is in an ordered way in a quarter of the tetrahedral holes of the next layer. The orientation of the protons of the amide ions is characteristic for this type of structure (filled up CdI₂ type).     

Wasserstoffbrückenbindungen in o- und m-Phenylendiammonium-aquapentafluorometallaten(III) (MIII = Al,Cr, Fe)

Hydrogen Bonds in o- and m-Phenylenediammonium Aquapentafluoro Metallates(III) (M^III = Al, Cr, Fe) m- and o-Phenylenediammonium-[M^IIIF₅(H₂O)] compounds of Al, Cr and Fe were synthesized and characterized by X-ray single crystal structure analysis. All structures are described in the space group P2₁2₁2₁ (Z = 4). m-Ph(NH₃)₂²⁺ (Ph(NH₃)₂²⁺ = phenylenediammonium) compounds: Al : a = 6.489(2), b = 7.943(2), c = 18.204(2) Å, R/wR = 0.084/0.050 for 1 533 reflections; Cr : a = 6.571(2), b = 8.006(2), c = 18.456(3) Å, R/wR = 0.050/0.040 for 1 571 reflections; Fe : a = 6.608(2), b = 8.052(2), c = 18.424(4) Å, R/wR = 0.042/0.034 for 1 947 reflections. o-Ph(NH₃)₂²⁺ compounds: Al : a = 6.580(2), b = 7.891(2), c = 18.319(5) Å, R/wR = 0.050/0.045 for 2 370 reflections; Cr : a = 6.642(2), b = 7.954(2), c = 18.484(4) Å, R/wR = 0.065/0.043 for 2 041 reflections; Fe : a = 6.693(2), b = 7.995(4), c = 18.529(7) Å, R/wR = 0.035/0.033 for 2 651 reflections. Isolated distorted octahedral [M^IIIF₅(H₂O)]^2? anions are connected by double O? H ?F hydrogen bonds of alternating strength to form chains in the b direction. Those chains, packed in a pseudohexagonal way, are further linked by the ammonium functions of the phenylenediammonium cations to a 3 D hydrogen bond network.     

Tripotassium Trichrome (III) Tetraphosphate K3Cr3(PO4)4: Synthèse, Étude Structurale,Caractérisation et Conductivité Ionique

The potassium chromium (III) phosphate K₃Cr₃(PO₄)₄ is prepared by a solid state reaction at 1173 K from a mixture of K₂CO₃, NH₄H₂PO₄, and (NH₄)Cr₂O₇. It is structurally characterized by single-crystal X-ray diffraction. It crystallizes in the Cmca (n°64) space group with a = 10.524(4) Åi, b = 20.466(6) Åi, c = 6.374(2) Åi, V = 1372.9(8) Åi³, Z = 4, R(F²) = 0.0452, and R _W (F²) = 0.1184 for 790 reflections with I > 2σ(I). The structure consists of CrO₆ octahedra and PO₄ tetrahedra sharing corners and edges to form a two-dimensional framework. The K⁺ cations are located in the interlayer space. Conductivity measurement leads to σ = 47.32 10^?5 Ω^?1 m^?1 at 729 K. K₃Cr₃(PO₄)₄ is a better ionic conductor than K₃Cr₃(AsO₄)₄ at the same temperature.     

Einkristallzüchtung und Strukturverfeinerung von RbAu und CsAu

Single-Crystal Growth and Structure Refinement of RbAu and CsAu Single-crystals of RbAu and CsAu were obtained by the reaction of the alkalimetal azides with gold-powder at 400°C. The structures were determined from X-ray single-crystal diffraktometer data: space group Pm3m, Z = 1; RbAu, a = 4.098(1) Å, R/R_w(w = 1) = 0.011/0.011, N(F_o²) ≥ 3σ(F_o²) = 41 and N(var.) = 4; CsAu, a = 4.258(1) Å, R/R_w(w = 1) = 0.009/0.010, N(F_o²) ≥ 3σ(F_o²) = 34 and N(var.) = 4. Both compounds crystallize in the completely ordered CsCl-type with neglible deviations from the ideal 1:1-composition.     

Darstellung und Struktur eines Ammoniumdiamidodioxophosphats(V), NH4PO2(NH2)2

Synthesis and Structure of an Ammonium Diamidodioxophosphate(V), NH₄PO₂(NH₂)₂ The ammonolysis of P₃N₅ under ammonothermal conditions (T = 400°C, p(NH₃) = 6 kbar, 14 d in autoclaves) in the presence of small definite amounts of water leads to the formation of NH₄PO₂(NH₂)₂. The structure was solved by single crystal X-ray methods. NH₄PO₂(NH₂)₂: P2₁/c (Nr. 14), a = 6.886(1) Å, b = 8.366(2) Å, c = 9.151(2) Å, β = 111.78(3)°, Z = 4, R₁/wR₂ = 0.026/0.072, Z(F > 2σ(F)) = 1183, N(variables) = 87. In NH₄PO₂(NH₂)₂ the anions [PO₂(NH₂)₂]^? are linked to chains by N? H …? N and N? H …? O bridge bonds. The ammonium ions are located between these chains and are donors for N? H …? O bridge bonds which connect the chains three-dimensionally.     

Contributions on thermal behaviour and crystal chemistry of anhydrous phosphates. XIX. Tri-chromium(II)-bis-phosphate Cr3(PO4)2 (≙ Cr6(PO4)4) – A transition metal(II)-orthophosphate with new structure type

Deep blue-violet single crystals of hitherto unknown chromous orthophosphate have been obtained reducing CrPO₄ by elemental Cr at temperatures above 1050°C in evacuated silica ampoules (NH₄I or I₂ as mineraliser). The complex structure of Cr₃(PO₄)₂ (P2₁2₁2₁, Z = 8, a = 8.4849(10) Å, b = 10.3317(10) Å, c = 14.206(2) Å) contains six crystallographically independent Cr²⁺ per unit cell. Five of them are coordinated by four oxygen atoms which form a distorted (roof shaped) square plane as first coordination sphere at interatomic distances 1.96 Å ? d(Cr? O) ? 2.15 Å. Their coordination is completed by additional oxygen atoms (2 or 3) at distances 2.32 Å ? d(Cr? O) ? 3.21 Å. The sixth Cr²⁺ shows six-fold octahedral coordination with strong radial distortion (d(Cr? O): 1.97, 2.04, 2.15, 2.28, 2.29, 2.53 Å). The four different [PO₄] groups exhibit only minor deviations from ideal tetrahedral geometry (1.51 Å ? d(P? O) ? 1.57 Å, 104.3° ? ∠(O? P? O) ? 114.4°). An unusually low magnetic moment μ_exp = 4.28(2) μ_B (θ_P = ?54.8(5) K) has been observed for Cr²⁺.     

Darstellung,Kristallstrukturen und Eigenschaften der Chrom(II)-phosphat-halogenide Cr2(PO4)Br und Cr2(PO4)I

Synthesis, Crystal Structures, and Properties of the Chromium(II) Phosphate Halides Cr₂(PO₄)Br and Cr₂(PO₄)I The new compounds Cr₂(PO₄)Br and Cr₂(PO₄)I have been obtained by reaction of CrPO₄, Cr and Br₂ or I₂ in evacuated silica tubes at elevated temperatures (Cr₂(PO₄)Br: 900 °C, Cr₂(PO₄)I: 700 °C). Single crystals of deep blue Cr₂(PO₄)Br and turquoise Cr₂(PO₄)I with edge-lengths up to 2 mm and 0.3 mm, respectively, have been grown in experiments involving the gaseous phase. Single crystal data have been used for structure determination and refinement. Though being not isotypic, the two crystal structures are closely related. Two crystallographically independent Cr²⁺, in polyhedra [Cr1O₃X₃] and [Cr2O₅X], form dimers [Cr1₂O₂O_2/2X₄] and [Cr2₂O₈X₂]. Distances are 1.978 Å ≤ d(Cr–O) ≤ 2.096 Å (for the iodide: 1.959 Å ≤ d(Cr–O) ≤ 2.105 Å), 2.587 Å ≤ d(Cr–Br) ≤ 3.158 Å and 2.867 Å ≤ d(Cr–I) ≤ 3.327 Å. The structures of bromide and iodide can be distinguished by the different way of connection of the Cr1 containing dimers. The phosphate group shows slightly distorted tetrahedral geometry with 1.491 Å ≤ d(P–O) ≤ 1.559 Å (1.486 Å ≤ d(P–O) ≤ 1.567 Å) and angles of 106.48° ≤ ∠(O–P–O) ≤ 111.69° (106.57° ≤ ∠(O–P–O) ≤ 111.72°. IR-spectra of Cr₂(PO₄)Br and Cr₂(PO₄)I, the Raman-spectrum of Cr₂(PO₄)Br and electronic spectra of the two compounds in the UV/vis region at low temperature are reported and discussed.     

Beiträge zum thermischen Verhalten und zur Kristallchemie von wasserfreien Phosphaten XXXII [1] Neue Orthophosphate des zweiwertigen Chroms — Mg3Cr3(PO4)4, Mg3, 75Cr2, 25(PO4)4, Ca3Cr3(PO4)4 und Ca2, 00Cr4, 00(PO4)4

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXII. New Orthophosphates of Divalent Chromium — Mg₃Cr₃(PO₄)₄, Mg_{3, 75}Cr_{2, 25}(PO₄)₄, Ca₃Cr₃(PO₄)₄ and Ca_{2, 00}Cr_{4, 00}(PO₄)₄ Solid state reactions via the gas phase led in the systems A₃(PO₄)₂ / Cr₃(PO₄)₂ (A = Mg, Ca) to the four new compounds Mg₃Cr₃(PO₄)₄ ( A ), Mg_3.75Cr_2.25(PO₄)₄ ( B ), Ca₃Cr₃(PO₄)₄ ( C ), and Ca_2.00Cr_4.00(PO₄)₄ ( D ). These were characterized by single crystal structure investigations [( A ): P2₁/n, Z = 1, a = 4.863(2) Å, b = 9.507(4) Å, c = 6.439(2) Å, β = 91.13(6)°, 1855 independend reflections, 63 parameters, R1 = 0.035, wR2 = 0.083; ( B ): P2₁/a, Z = 2, a = 6.427(2) Å, b = 9.363(2) Å, c = 10.051(3) Å, β = 106.16(3)°, 1687 indep. refl., 121 param., R1 = 0.032, wR2 = 0.085; ( C ): P‐1, Z = 2, a = 8.961(1) Å, b = 8.994(1) Å, c = 9.881(1) Å, α = 104.96(2)°, β = 106.03(2)°, γ = 110.19(2)°, 2908 indep. refl., 235 param., R1 = 0.036, wR2 = 0.111; ( D ): C2/c, Z = 4, a = 17.511(2) Å, b = 4.9933(6) Å, c = 16.825(2) Å, β = 117.95(1)°, 1506 indep. refl., 121 param., R1 = 0.034, wR2 = 0.098]. The crystal structures contain divalent chromium on various crystallographic sites, each showing a (4+n)‐coordination (n = 1, 2, 3). For the magnesium compounds and Ca_2.00Cr_4.00(PO₄)₄ a disorder of the divalent cations Mg²⁺/Cr²⁺ or Ca²⁺/Cr²⁺ is observed. Mg_3.75Cr_2.25(PO₄)₄ adopts a new structure type, while Mg₃Cr₃(PO₄)₄ is isotypic to Mg₃(PO₄)₂. Ca₃Cr₃(PO₄)₄ and Ca_2.00Cr_4.00(PO₄) ₄ are structurally very closely related and belong to the Ca₃Cu₃(PO₄)₄‐structure family. The orthophosphate Ca₉Cr(PO₄)₇, containing trivalent chromium, has been obtained besides C and D .     

Neue Fluorperowskite mit Cr‴ und Mn‴: A(B03Cr0.5)F3 und A(B05Mn0,5)F3; A,B=Alkalimetall

New fluoroperovskites with Cr^III and Mn^III: A(B_0.5Cr_0.5)F₃ and A(B_0.5Mn_0.5)F₃; A, B = alkali We obtained Cs₂KCrF₆ (a = 9.00₄ Å), Rb₂KCrF₆ (a = 8.81₇ Å), Rb₂NaCrF_e(a = 8.41₈ Å) (all green, K₂NaCrF₆-type) and Cs₂NaCrF₈ as well as Rb₂NaMnF₆ (tetragonally distorted K₂NaCrF₆-type; a = 8.36₅, c = 8.66₀ Å; F4/mmm), and Rb₂KMnF₆ and Cs₂NaMnF₆, all violet. Jahn-Teller-distortion and lattice energy of Rb₂NaMnF₆ and K₂NaMnF₆ are discussed.     

Na5Br(OH)4: Darstellung und Kristallstruktur einer Verbindung im System NaOH/NaBr

Na₅Br(OH)₄: Synthesis and Structure of a Compound in the System NaOH/NaBr The pseudobinary system NaOH/NaBr is investigated by X-ray methods. The structure of the compound Na₅Br(OH)₄ was solved by single crystal data: Na₅Br(OH)₄: Pnma, Z = 8, a = 11.846(2) Å, b = 18.782(4) Å, c = 6.431(1) Å, Z(F_o) = 1 202 with (F_o)² ≥ 3σ(F_o)², Z(parameter) = 100, R/R_w = 0.030/0.035 The compound crystallizes in a new type of structure. Pairs of octahedra around O by 5 Na and 1 H to [Na₅(OH)]₂ are orientated in such a way to one another that two ions OH^? form a parallelogram hinting to unusual bent hydrogen bridge bonding.     

Synthesis and Crystal Structure of Dinitratotetra(hexamethylphosphoric Triamide)-Lanthanum(III)Tetra(Isothiocyanato)Diammine Chromate(III)

A new coordination compound having the formula [La(HMPA)₄(NO₃)₂][Cr(NH₃)₂(NCS)₄] (I), where HMPA is ((CH₃)₂N)₃PO, has been synthesized and studied by X-ray diffraction. Studied crystals of compound I are monoclinic, space group P2₁/n, a = 15.0360(3) Å, b = 15.1214(3) Å, c = 26.7529(7) Å, β = 100.6610(10)°, V = 5977.7(9) Å3, Z = 2, ρ_calc = 1.442 g/cm³, and R₁ = 0.0453 for 7344 reflections with F_o ≥ 4σ(F_o).