Die Perthioborate RbBS3, TIBS3 und TI3B3S10

The Perthioborates RbBS₃, TIBS₃, and Tl₃B₃S₁₀ . RbBS₃ (P2₁/c, a=7.082(2) Å, b=11.863(4) Å, c=5.794(2) Å, β=106.54(2)°) was prepared as colourless, plate-shaped crystals by reaction of stoichiometric amounts of rubidium sulfide, boron, and sulfur at 600°C and subsequent annealing. TlBS₃ (P2₁/c, a=6.874(3) Å, b=11.739(3) Å, c=5.775(2) Å, β=113.08(2)°) which is isotypic with RbBS₃ was synthesized from a sample of the composition Tl₂S · 2 B₂S₃. The glassy product which was obtained after 7 h at 850°C was annealed in a two zone furnace for 400 h at 400→350°C. Yellow crystals of TlBS₃ formed at the warmer side of the furnace. Tl₃B₃S₁₀ (P1 , a=6.828(2) Å, b=7.713(2) Å, c=13.769(5) Å, α=104.32(2)°, β=94.03(3)°, γ=94.69(2)°) was prepared as yellow plates from stoichiometric amounts of thallium sulfide, boron, and sulfur at 850°C and subsequent annealing. All compounds contain tetrahedrally coordinated boron. The crystal structures consist of polymeric anion chains. In the case of RbBS₃ and TlBS₃ nonplanar five-membered B₂S₃ rings are spirocyclically connected via the boron atoms. To obtain the anionic structure of Tl₃B₃S₁₀ every third B₂S₃ ring of the polymeric chains of MBS₃ is to be substituted by a six-membered B(S₂)₂B ring.     

Preparation and Structure Determination of SrMn2(PO4)2 and Redetermination of b ′‐Mn3(PO4)2

Pale rose single crystals of SrMn₂(PO₄)₂ were obtained from a mixture of SrCl₂ · 6 H₂O, Mn(CH₃COO)₂, and (NH₄)₂HPO₄ after thermal decomposition and finally melting at 1100 °C. The new crystal structure of strontium manganese orthophosphate [P‐1, Z = 4, a = 8.860(6) Å, b = 9.054(6) Å, c = 10.260(7) Å, α = 124.27(5)°, β = 90.23(5)°, γ = 90.26(6)°, 4220 independent reflections, R1 = 0.034, wR2 = 0.046] might be described as hexagonal close‐packing of phosphate groups. The octahedral, tetrahedral and trigonal‐bipyramidal voids within this [PO₄] packing provide different positions for 8‐ and 10‐fold [SrO_x] and distorted octahedral [MnO₆] coordination according to a formulation Mn Mn Mn Sr (PO₄)₄. Single crystals of β′‐Mn₃(PO₄)₂ (pale rose) were grown by chemical vapour transport (850 °C → 800 °C, P/I mixtures as transport agent). The unit cell of β′‐Mn₃(PO₄)₂ [P2₁/c, Z = 12, a = 8.948(2) Å, b = 10.050(2) Å, c = 24.084(2) Å, β = 120.50°, 2953 independent reflections, R1 = 0.0314, wR2 = 0.095] contains 9 independent Mn²⁺. The reinvestigation of the crystal structure led to distinctly better agreement factors and significantly reduced standard deviations for the interatomic distances.     

Etude Structurale de la forme basse Température de NH4Sn2F5 (Type γ)

Structural Study of the Low-temperature Modification of NH₄Sn₂F₅ (Type γ) NH₄Sn₂F₅, monoclinic, space group C2, Cm or C2/m, a = 7.361(4) Å, b = 12.752(6) Å, c = 10.492(5) Å, β = 103.5(7)°, V = 957,2(9) ų, Z = 6. MoKα (= 0.7107 Å) R = 0.036 for 476 observed reflexions. The structure is built from alternative layers [Sn? F] and [NH₄⁺]. Three kinds of fluorine have vacancy positions, that explains the bidimensional conduction in NH₄Sn₂F₅.     

Zur Darstellung und Struktur von M1?LnTa3O9 (Ln = Pr,Nd) Röntgenographische und elektronenmikroskopische Untersuchungen

Preparation and Structure of M1? LnTa₃O₉ (Ln = Pr, Nd), X-Ray and Electronmicroscopical Investigations New ternary compounds M1? LnTa₃O₉ (Ln = Pr, Nd) could be prepared by chemical transport reaction in a temperature gradient T₂ → T₁ (T₂ = 1100°C; T₁ = 1000°C; CI₂ as transport agent). M1 NdTa₃O₉ crystallizes in the monoclinic space group P 2₁/m with a = 5.3840(9) Å, b = 7.550(1) Å, c = 8.1911(9) Å and β = 92.46(1)°. The structure was refined to give R = 6.29% and R_w = 6.20%. It is built of double and single chains of corner-sharing TaO₆ octahedra extended along the b-axis. Tunnels running along [010] are created by the framework of TaO₆ octahedra. Ln (Ln = Pr, Nd) is located in these tunnels to levels of y = 1/4 and 3/4. A structure refinement for isostructural M1? PrTa₃O₉ led to a = 5.4051(7) Å, b = 7.5680(2) Å, c = 8.1964(9) Å, β = 92.38(2)° and R = 7.72%, R_w = 7.57%. By grinding in an agate mortar M1? LnTa₃O₉ transforms into M2? LnTa₃O₉, a new modification with a higher density. High resolution transmission electron microscopy images of the M1? PrTa₃O₉ structure were made along the [010] direction. They could be interpreted by comparing them with images calculated on the basis of the multi-slice method.     

Zur Darstellung und Struktur von LaTa7O19 Röntgenographische und elektronenmikroskopische Untersuchungen

Preparation and Structure of LaTa₇O₁₉. X-Ray and Electronmicroscopic Investigations In the system La₂O₃/Ta₂O₅ a new ternary compound LaTa₇O₁₉ could be prepared by chemical transport in a temperature gradient T₂ → T₁ (1120 → 1020°C; Cl₂ was added). LaTa₇O₁₉ is hexagonal, space group P6 with the lattice constants a = 6.23₆ and c = 19.99₅ Å. In the structure double layers of pentagonal TaO₇-bipyramids are recognizable perpendicular to [001]-direction. They alternate with a single layer consisting of La? O and Ta? O coordination polyhedra. Images of the structure were made with high resolution transmission electron microscopy along the [001]-direction. Despite the length of the axis the computer simulation based on the multi-slice method agreed well with the experimental images.     

Beiträge zum thermischen Verhalten wasserfreier Phosphate. VII. Darstellung,Struktur und thermisches Verhalten von orthorhombischem NbPO5–δ

Contributions on the Thermal Behaviour of Anhydrous Phosphates. VII Preparation, Structure, and Thermal Behaviour of Orthorhombic NbPO_5–δ By a chemical vapour transport in a temperature gradient (e.g. 1000° → 9000°C) it is possible to prepare the already known forms of NbPO₅ and a new phase as single crystals. Using I₂ or NH₄Cl as transport agents α?NbPO₅ was obtained as colourless crystals, which enabled a refinement of the already known tetragonal crystal structure to R = 1.73%. The dark blue crystals of the up to now unknown orthorhombic phase could only be prepared under reducing conditions (by adding NbP). Their crystall structure is related to monoclinic β-NbPO₅ (single crystall investigation, space group Pna2₁; a = 11.2875 Å; b = 6.6296 Å; c = 5.2871 Å; Z = 4; R = 3.17%), but the crystals are deficient in oxygen according to NbPO_5?δ recognizable by the dark blue colour. When NbPO_5?δ (orthorhombic) is ground in an agate mortar NbPO_5?δ (monoclinic) is formed, which has the already known structure of β-NbPO₅. By heating (340°C) a reversible transformation from NbPO_5?δ (monoclinic) to NbPO_5?δ (orthorhombic) takes place. This is isostructural to WPO₅ and also to an orthorhombic modification of (colourless) NbPO₅, which we also could observe above 340°C.     

Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXIII [1] In2P2O7, ein Indium(I)‐diphosphato‐indat(III) und In4(P2O7)3 — Darstellung,Kristallisation und Kristallstrukturen

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXIII [1] In₂P₂O₇ an Indium(I)‐diphosphatoindate(III), and In₄(P₂O₇)₃ — Synthesis, Crystallization, and Crystal Structure Solid state reactions via the gas phase lead to the new mixed‐valence indium(I, III)‐diphosphate In₂P₂O₇. Colourless single crystals of In₂P₂O₇ have been grown by isothermal heating of stoichiometric amounts of InPO₄ and InP (800 °C; 7d) using iodine as mineralizer. The structure of In₂P₂O₇ [P2₁/c, a = 7.550(1) Å, b = 10.412(1) Å, c = 8.461(2) Å, b = 105.82(1)°, 2813 independent reflections, 101 parameter, R1 = 0.031, wR2 = 0.078] is the first example for an In⁺ cation in pure oxygen coordination. Observed distances d(In^I‐O) are exceptionally long (d_min(In^I‐O) = 2.82 Å) and support assumption of mainly s‐character for the lone‐pair at the In⁺ ion. Single crystals of In₄(P₂O₇)₃ were grown by chemical vapour transport experiments in a temperature gradient (1000 → 900 °C) using P/I mixtures as transport agent. In contrast to the isostructural diphosphates M₄(P₂O₇)₃ (M = V, Cr, Fe) monoclinic instead of orthorhombic symmetry has been found for In₄(P₂O₇)₃ [P2₁/a, a = 13.248(3) Å, b = 9.758(1) Å, c = 13.442(2) Å, b = 108.94(1)°, 7221 independent reflexes, 281 parameter, R1 = 0.027, wR2 = 0.067].     

Zur Darstellung und Struktur neuer Modifikationen von CeTa3O9

Preparation and Structure of New CeTa₃O₉ Modifications The modifications M? , O? and P? CeTa₃O₉ could be prepared by chemical transport reactions (T₂ → T₁; T₂ = 1100°C; T₁ = 1000°C) with chlorine as transport agent. M? CeTa₃O₉ crystallizes in the monoclinic space group C 2/m with a = 12.415(1) Å, b = 7.6317(8) Å, c = 6.5976(8) Å, β = 93.31(1)°; Z = 4; R = 4.88%, R_w = 3.67%. The structure consists of two types of Ta? O-polyhedra. Especially remarkable are chains of edge sharing pentagonal TaO₇-bipyramids which are connected by TaO₆-octahedra at opposite sides. Tunnels running along [010] are created by the framework of Ta? O-polyhedra and are filled with Ce in levels of y = 1/2 and y = 0. O? CeTa₃O₉ crystallizes orthorhombically with a = 6.5429(7) Å, b = 7.6491(7) Å, c = 12.583(1) Å and is isostructural to O? LaTa₃O₉ (space group: Pnma). O? CeTa₃O₉ contains the same characteristic structural units namely pentagonal TaO₇-bipyramides and TaO₆-octahedra. The difference between O? and M? CeTa₃O₉ is based on the orientation of the tunnels: in the orthorhombic modification they are arranged zigzag-like, in the latter parallel. Both modifications of CeTa₃O₉ can be irreversibly converted into the well-known perovskite-related P? CeTa₃O₉ structure with a lower density by heating in air to 1200°C.     

Penta‐Ammoniates of Aluminium Halides: The Crystal Structures of AlX3·5NH3 with X = Cl,Br, I

Colourless crystals grow in the colder part of a glass ampoule when AlX₃·5NH₃ with X = Cl, Br, I is heated for 3—6 d to 330 °C (Cl), 350 °C (Br) and 400 °C (I), respectively. The chloride forms hexagonal prisms while the bromide and iodide were obtained as a bunch of lancet‐like crystals. The chloride and bromide crystallize isotypic whereas the iodide has an own structure type. All three are related to the motif of the K₂PtCl₆ type. So the formula of the ammoniates may be written as X₂[Al(NH₃)₅X] ≙ [Al(NH₃)₅X]X₂. The compounds are characterized by the following crystallographic data AlCl₃·5NH₃: Pnma, Z = 4, a = 13.405 (1)Å, b = 10.458 (1)Å, c = 6.740 (2)Å AlBr₃·5NH₃: Pnma, Z = 4, a = 13.808 (2)Å, b = 10.827 (1)Å, c = 6.938 (1)Å AlI₃·5NH₃: Cmcm, Z = 4, a = 9.106 (2)Å, b = 11.370 (2)Å, c = 11.470 (2)Å For the chloride and the bromide the structure determinations were successful including hydrogen positions. All three compounds contain octahedral molecular cations [Al(NH₃)₅X]²⁺ located in distorted cubes formed by the remaining 2X^— ions. The orientation of the octahedra to each other is clearly different for those with X = Cl, Br in comparison to the one with X = I.     

Ein neues Praseodymniobat Pr2Nb11O30

A New Praseodymiumniobate Pr₂Nb₁₁O₃₀ By chemical vapor transport (T₂ → T₁, T₂ = 950 °C, T₁ = 900 °C, 3 d) of a mixture of PrOCl and Nb₂O₅ (1 : 1) using 5 mg NH₄Cl as transport agent we obtained the new compound Pr₂Nb₁₁O₃₀. The crystal structure determination [a = 6.2325(5) Å, c = 32.3677(36) Å, Z = 2, 1631 independent I₀, 69 parameters, R1 = 2.07%] shows CN = 8 (twofold capped octahedrally) for Pr, CN = 7 (pentagonal bipyramidally) for Nb(1,2) and CN = 6 (octahedrally) for Nb(3). The structure is closely related to that of Cu₅Ta₁₁O₃₀.     

Zur Darstellung und Struktur von LaTa3O9 Röntgenographische und elektronenmikroskopische Untersuchungen

Preparation and Structure of LaTa₃O₉. X-Ray and Electronmicroscopic Investigations In the system La₂O₃/Ta₂O₅ a new ternary compound LaTa₃O₉ could be prepared by chemical transport in a temperature gradient T₂ → T₁ (1100 → 1040°C; Cl₂ was added). LaTa₃O₉ is orthorhombic, space group Pnma–D with the lattice constants a = 6.59₅, b = 7.66₄, and c = 12.48₁ Å. In the structure ribbons of pentagonal TaO₇-bipyramids are recognizable parallel to the a-direction. These ribbons are connected with each other in the (010) plane by TaO₆-octahedra. The tunnels formed in this way are occupied by La atoms. High resolution transmission electron microscopy images of the structure were made along the [010] direction. They were interpreted by using images calculated on the basis of the multi-slice method.     

Zur Darstellung und Struktur von LaNb5O14

Preparation and Structure of LaNb₅O₁₄ Single crystals of LaNb₅O₁₄ could be prepared by chemical transport reactions (T₂ → T₁; T₂ = 1050°C; T₁ = 950°C) using chlorine as transport agent. LaNb₅O₁₄ crystallizes in the orthorhombic space group Pbem with cell dimensions a = 3.8749(2) Å; b = 12.4407(6) Å and c = 20.2051(9) Å; Z = 4; R = 6.28%, R_w = 3.74%. The structure consists of two types of Nb? O-polyhedra. Especially remarkable are chains of edge-sharing pentagonal NbO₇-bipyramids, which are interconnected by corner-sharing NbO₆-octahedra. Tunnels running in a-direction are created by this framework of NbO₆- and NbO₇-polyhedra. Lanthanum atoms are located in these tunnels at levels inbetween the niobium atoms. The relationship to O? LaTa₃O₉ and M? CeTa₃O₉ type structures will be discussed.     

Homo- und heterodinukleare α-Pyridonat-verbrückte Platin- und Palladium-komplexe mit Bis(N-methylimidazol-2-yl)keton (BMIK). Kristallstrukturen von [(BMIK)Pt(α-Pyridonat)2Pt(BMIK)](NO3)2 · 4H2O, [(BMIK)Pd(α-Pyridonat)2Pd(BMIK)](NO3)2 · 4H2O und [(BMIK)Pd(α-Pyridonat)2Pt/Pd(BMIK)](NO3)2 · 4H2O

Homo- and Heterodinuclear α-Pyridonate-bridged Platinum and Palladium Complexes with Bis(N-methylimidazol-2-yl)ketone (BMIK). Crystal Structures of [(BMIK)Pt(α-pyridonate)₂Pt(BMIK)](NO₃)₂ · 4H₂O, [(BMIK)Pd(α-pyridonate)₂Pd(BMIK)](NO₃)₂ · 4H₂O, and [(BMIK)Pd(α-pyridonate)₂Pt/Pd(BMIK)](NO₃)₂ · 4H₂O The isotypic dinuclear complexes [(BMIK)Pt(α-pyridonate)₂Pt(BMIK)](NO₃)₂ · 4H₂O ( 1 ) (P1 ; a = 12.197(5) Å, b = 12.505(5) Å, c = 12.866(5) Å, α = 88.17(3)°, β = 73.55(3)°, γ = 69.84(3)°; Z = 2) and [(BMIK)Pd(α-pyridonate)₂Pd(BMIK)](NO₃)₂ · 4H₂O ( 2 ) (a = 12.408(3) Å, b = 12.660(3) Å, c = 12.913(3) Å, α = 89.55(3)°, β = 74.59(2)°, γ = 68.68(2)°) were prepared by reaction of [Pt(BMIK)(H₂O)₂](NO₃)₂ or [Pd(BMIK)(H₂O)₂](NO₃)₂ with α-pyridone in aqueous solutions at 40°C and were isolated as red air-stable crystals (BMIK = bis(N-methylimidazol-2-yl)ketone). For the synthesis of mixed crystals of 2 with the heterometal complex [(BMIK)Pd(α-pyridonate)₂Pt(BMIK)](NO₃)₂ · 4H₂O ( 3 ) (a = 12.430(4) Å, b = 12.648(3) Å, c = 12.907(4) Å, α = 89.64(2)°, β = 74.57(2)°, γ = 68.65(2)°) α-pyridone was reacted with [Pd(BMIK)(H₂O)₂](NO₃)₂ in a molar ratio of 2 : 1 followed by addition of [Pt(BMIK)(H₂O)₂](NO₃)₂. The dinuclear cations consist of two M(BMIK) moieties (M = Pt, Pd) bridged by the N- and O-atoms of α-pyridonate, forcing the heterocyclic ring into head-head-orientation. Within the dinuclear cation, the two metal atoms are between 2.840 Å and 2.860 Å apart. The intermolecular distances are between 4.762 Å and 4.837 Å. The coordination geometry of both metal atoms is square-planar with the metal atoms being diplaced slightly from their respective coordination planes toward each other. ¹H and ¹⁹⁵Pt NMR spectra are reported for the complexes.     

Synthesis and X-Ray Structure of New Copper(II) Nitrates: Cu(NO3)2 · H2O and β-modification of Cu(NO3)2

Blue crystals of a Cu(NO₃)₂ · H₂O were synthesized by interaction of CuO with boiling 100% HNO₃. Stable β-Cu(NO₃)₂ modification was obtained by the sublimation of copper(II) nitrate in evacuated ampoule over the 150→100°C temperature gradient for 24 hr. According to X-Ray single crystal analysis Cu(NO₃)₂ · H₂O is monoclinic with a = 6.377(1), b = 8.548(1), c = 9.769(1) Å, β = 100.41(1)°, Z = 4, and space group P2₁/c. β-modification Cu(NO₃)₂ is orthorhombic with a = 14.161(5), b = 7.516(3), c = 12.886(2) Å, Z = 12, and space group Pbcn. In the both structures Cu atoms are square coordinated by 4 O atoms at the distances ranging from 1.92 to 2.02 Å. In each structure there are also additional Cu? O bonds with the distance of 2.33 or 2.35 Å and some weaker ones with the distances in the range of 2.65–2.72 Å. In the Cu(NO₃)₂ · H₂O structure the [CuO₄] squares are connected by the bridging NO₃ groups into zigzag chains, which are linked into layers by the longer Cu? O bonds. In the β-Cu(NO₃)₂ structure the [CuO₄] fragments of two types are joined by the bridging NO₃ groups in a three-dimensional framework. Some correlations were found between N? O distances and coordination functions of O atoms.     

Preparation and Characterization of a Heteronuclear μ-Alkyne Complex; X-Ray Crystal Structure of MoCo(CO)4(PPh3){μ-HCCSiMe3)(η5-C5H5)

Reaction of MoCo(CO)₅(PPh₃)₂(η⁵-C₅H₅) (1a) with trimethylsilylacetylene in tetrahydrofuran at 58° C yielded two acetylene bridged heterobimetallic compounds, MoCo(CO)₄(PPh₃){μ-HC?CSiMe₃}(η⁵-C₅H₅) (4) and MoCo (CO)₅{μ-HC?CSiMe₃}(η⁵-C₅H₅)(5). (4) was characterized by mass, infrared, ¹H, ¹³C and ³¹P NMR spectra. The X-ray crystal structure of (4) was determined:triclinic, P-1, a=8.821(1) Å, b=11.315(3) Å, c=17.029(2) Å, α=70.73(1)°, β=78 .72(1)°, γ=86.10(2)°,V =1573.4(6) ų, Z=2, R = 3.92%,R_w = 6.06% for 4285 (F > 4σ (F)) observed reflections. The core of this molecule is a quasi-tetrahedron containing Mo, Co and two carbons of acetylene. The triphenylphosphine ligand is attached to cobalt rather than molybdenum center.     

Darstellung und Struktur von U2Ta6O19, einer neuen Verbindung mit „Jahnberg‐Struktur”︁, sowie Anmerkungen zu den ersten Oxidchloriden in den Systemen Th/Nb/O/Cl und Th/Zr(Hf)/Nb/O/Cl

Synthesis and Crystal Structure of U₂Ta₆O₁₉, a New Compound with “Jahnberg‐Structure” and a Note to the First Oxide Chlorides in the Systems Th/Nb/O/Cl and Th/Zr(Hf)/Nb/O/Cl Black crystals of U₂Ta₆O₁₉ with hexagonal shape were obtained (at T₁) by chemical transport using HCl (p (HCl, 298 K) = 1 atm; silica tube) as transport agent in a temperature gradient (T₂ → T₁; 1000 °C → 950 °C) and using a mixture of UO₂, Ta₂O₅, and HfO₂ (or ZrO₂) (1 : 2 : 2) as starting materials (at T₂). For the structure determination the best result was achieved in space group P6₃/mcm (No. 193, a = 6.26(2) Å, c = 19.86(6) Å). U₂Ta₆O₁₉ is isotypical to Th₂Ta₆O₁₉. In the crystal structure each uranium atom is surrounded by oxygen atoms like a bi‐capped trigonal antiprism and tantalum atoms like a pentagonal bipyramid (CN = 7). Like the “Jahnberg Structures” both coordination polyhedra arrange themselves in separate layers (U–O‐polyhedra, in o‐, Ta–O‐polyhedra in p‐layers) so that in the direction of the c‐axis the sequence of layers is p‐p‐o. Using chemical transport it was possible to prepare the compounds Th₁₂Nb₁₆O₆₃Cl₂ and Th₈M₄Nb₁₆O₆₃Cl₂ (M = Zr, Hf), which are the first quaternary and quinquinary examples in these systems. They crystallize isotypically.     

Präparation,Kristallstruktur und thermisches Verhalten der Quecksilber(I)phosphate α-(Hg2)3(PO4)2, β-(Hg2)3(PO4)2 und (Hg2)2P2O7

Contributions on Crystal Structures and Thermal Behaviour of Anhydrous Phosphates. XXIII. Preparation, Crystal Structure, and Thermal Behaviour of the Mercury(I) Phosphates α-(Hg₂)₃(PO₄)₂, β-(Hg₂)₃(PO₄)₂, and (Hg₂)₂P₂O₇ Light-yellow single crystals of (Hg₂)₂P₂O₇ have been obtained via chemical vapour transport in a temperature gradient (500 °C → 450 °C, 23 d) using Hg₂Cl₂ as transport agent. Characteristic feature of the crystal structure (P2/n, Z = 2, a = 9,186(1), b = 4,902(1), c = 9,484(1) Å, β = 98,82(2)°, 1228 independent of 5004 reflections, R(F) = 0,066 for 61 variables, 7 atoms in the asymmetric unit) are Hg₂²⁺-units with d(Hg1–Hg1) = 2,508 Å and d(Hg2–Hg2) = 2,519 Å. The dumbbells Hg₂²⁺ are coordinated by oxygen, thus forming polyhedra [(Hg1₂)O₄] and [(Hg2₂)O₆]. These polyhedra share some oxygen atoms. In addition they are linked by the diphosphate anion P₂O₇^4– (ecliptic conformation; ∠(P,O,P) = 129°) to built up the 3-dimensional structure. Under hydrothermal conditions (T = 400 °C) orange single crystals of the mercury(I) orthophosphates α-(Hg₂)₃(PO₄)₂ and β-(Hg₂)₃(PO₄)₂ have been obtained from (Hg₂)₂P₂O₇ and H₃PO₄ (c = 1%). The crystal structures of both modifications have been refined from X-ray single crystal data [α-form (β-form): P2₁/c (P2₁/n), Z = 2 (2), a = 8,576(3) (7,869(3)), b = 4,956(1) (8,059(3)), c = 15,436(3) (9,217(4)) Å, β = 128,16(3) (108,76(4))°, 1218 (1602) independent reflections of 4339 (6358) reflections, R(F) = 0,039 (0,048) for 74 (74) variables, 8 (8) atoms in the asymmetric unit]. In the structure of α-(Hg₂)₃(PO₄)₂ three crystallographically independent mercury atoms, located in two independent dumbbells, are coordinated by three oxygen atoms each. Thus, [(Hg₂)O₆] dimers with a strongly distorted tetrahedral coordination of all mercury atoms are formed. Such dimers are present besides [(Hg₂)O₅]-polyhedra in the less dense crystal structure of β-(Hg₂)₃(PO₄)₂ (d(Hg–Hg) = 2,518 Å). The mercury(I) phosphates are thermally labile and disproportionate between 200 °C (β-(Hg₂)₃(PO₄)₂) and 480 °C (α-(Hg₂)₃(PO₄)₂) to elemental mercury and the corresponding mercury(II) phosphate.     

Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXVI [1] Synthese,Kristallstruktur und spektroskopische Charakterisierung von Palladium(II)‐diphosphat Pd2P2O7

Synthesis, Crystal Structure and Spectroscopical Characterization of Palladium(II)‐Diphosphate Pd₂P₂O₇ Pd₂P₂O₇ is synthesized by heating (T_max = 500 °C) stoichiometric amounts of PdO and phosphoric acid. Using chemical vapour transport experiments (850 °C → 750 °C, addition of PdCl₂) Pd₂P₂O₇ was crystallized. Pd₂P₂O₇ adopts its own structure type (C 2/c (No. 15), Z = 4, a = 13,151(2) Å, b = 5,172(1) Å, c = 8,139(1) Å, β = 97,52(1)°, 1160 independent reflections, 55 variables, R1 = 0,021 and wR2 = 0,050). Square‐planar [PdO₄]‐units are linked by diphosphate‐groups generating a 3D framework. Within this framework ribbons may be distinguished. Thus Pd₂P₂O₇ might be described as palladium(II)‐[diphosphatopalladate(II)]. The results of various spectroscopic measurements (IR, Raman, UV/VIS, ³¹P‐MAS‐NMR) are reported and discussed within the context of the crystal structure.     

Darstellung und Struktur von Ln3TiO4Cl5(Ln = La − Nd) - die ersten Oxochlorotitanate der Seltenen Erden

Preparation and Crystal Structure of Ln₃TiO₄Cl₅ (Ln = La?Nd) – the First Oxochlortitanates of Rare Earth The compounds Ln₃TiO₄Cl₅ have been prepared by reaction of LnCl₃/LnOCl/TiO₂ (1:2:1) (Ln = La?Nd) in evacuated silica ampoules. Single crystals of La₃TiO₄Cl₅ were obtained by chemical transport reaction (T₂ → T₁; T₂ = 1050°C, T₁ = 950°C) using chlorine (p(Cl₂; 298 K) = 1 atm) and sulfur as transport agents with La₂TiO₅ as starting material. La₃TiO₄Cl₅ crystallizes in the orthorhombic space group Pnma (No. 62) with cell-dimensions a = 16.760(2) Å, b = 4.0991(6) Å, c = 14.634(2) Å, Z = 4. The structure was refined to give R = 4.76%, R_w = 2.47%. Main building units are TiO₅ trigonal bipyramides and threefold capped trigonal prisms around La. The relationship to La₂TaO₄Cl₃ will be discussed.     

Beiträge zum Koordinationsverhalten von Oxidionen in anorganischen Feststoffen. III [1] Mn2P2O7, Mn2P4O12 und Mn2Si(P2O7)2 — Kristallzüchtung,Strukturverfeinerungen und Elektronenspektren von Mangan(II)‐Phosphaten

Contributions on the Bonding Behaviour of Oxygen in Inorganic Solids. III [1] Mn₂P₂O₇, Mn₂P₄O₁₂ und Mn₂Si(P₂O₇)₂ — Crystal Growth, Structure Refinements and Electronic Spectra of Manganese(II) Phosphates By chemical vapour transport reactions in a temperature gradient single crystals of Mn₂P₂O₇ (1050 → 950 °C) and Mn₂P₄O₁₂ (850 → 750 °C) have been obtained using P/I mixtures as transport agent. Mn₂Si(P₂O₇)₂ was crystallized by isothermal heating (850 °C, 8d; NH₄Cl as mineralizer) of Mn₂P₄O₁₂ und SiO₂. In Mn₂Si(P₂O₇)₂ [C 2/c, a = 17.072(1)Å, b = 5.0450(4)Å, c = 12.3880(9)Å, β = 103.55(9)°, 1052 independent reflections, 97 variables, R1 = 0.023, wR2 = 0.061] the Mn²⁺ ions show compressed octahedral coordination (d¯_Mn—O = 2.19Å). The mean distance d¯_Mn—O = 2.18Å was found for the radially distorted octahedra [MnO₆] in Mn₂P₄O₁₂ [C 2/c, Z = 4, a = 12.065(1)Å, b = 8.468(1)Å, c = 10.170(1)Å, β = 119.29(1)°, 2811 independent reflections, 85 variables, R1 = 0.025, wR2 = 0.072]. Powder reflectance spectra of the three pink coloured manganese(II) phosphates have been measured. The spectra show clearly the influence of the low‐symmetry ligand fields around Mn²⁺. Observed d—d electronic transition energies and the results of calculations within the framework of the angular overlap model (AOM) are in good agreement. Bonding parameters for the manganese‐oxygen interaction in [Mn²⁺O₆] chromophors as obtained from the AOM treatment (B, C, Trees correction α, e_σ, e_π) are discussed.