Hydrogen Bonds in Rubidium Amide‐Ammonia(3/2), RbNH2·2/3NH3

Rubidium amide‐ammonia(3/2), RbNH₂·2/3NH₃, was synthesized from Rubidiumhydride, RbH, in liquid ammonia at ?78 °C. The compound crystallizes in the cubic space group I2₁3 with Z = 4, a = 10.0490(12) Å, and V = 1014.77(20) Å as isometric colorless crystals. The crystal structure was solved from single‐crystal X‐ray data. The structure contains a three‐dimensional network of amide anions and ammonia molecules, which are interconnected via hydrogen bonds.     

The Complex Amide K2[Zr(NH2)6]

We present the low‐temperature synthesis of potassium hexaamido zirconate(IV) from the transition metal tetrafluoride and thealkali metal dissolved in liquid ammonia at –40 °C. Potassium hexaamido zirconate(IV) K₂[Zr(NH₂)₆] is the first ternary amide reported for elements of group 4 of the periodic table It crystallizes with a novel structure type in the trigonal space group R$\bar{3}$ c with a = 6.5422(2) Å, c = 32.824(2) Å, V = 1216.66(9) Å³, Z = 6 and c/a = 5.017. The structure can be derived from the K₂PtCl₆ type. The compound contains discrete D₃‐symmetric [Zr(NH₂)₆]^2– anions which differ significantly from octahedral shape. Quantum chemical calculations show the distortion to arise from a splitting of degenerate d‐orbitals on the zirconium atom leading to a significant gain in energy.     

Reaction of RGeBr3 (R=iPr2C6H3NSiMe3) with Ammonia To Give (RGe)2(NH2)4(NH): A Compound Containing Terminal NH2 Groups

The surprisingly facile preparation of (RGe)₂(NH₂)₄(NH) ( 1 ; R=iPr₂C₆H₃NSiMe₃), which contains one NH and four NH₂ groups, is achieved by the introduction of gaseous ammonia into a solution of iPr₂C₆H₃NSiMe₃GeBr₃ in diethyl ether.     

Reactions in Anhydrous Liquid Ammonia: Syntheses and Crystal Structures of [M(NH3)8]I2 (M = Eu,Yb) with Bicapped Trigonal-Prismatic Octaammine Lanthanoid(II) Cations

The compounds [M(NH₃)₈]I₂ (M = Eu, Yb) were obtained from reactions in anhydrous liquid ammonia solutions as side products. They were characterized by single-crystal X-ray diffraction and found to be isotypic to the compounds [Ca(NH₃)₈]X₂ (X = Cl, Br, I). The coordination sphere of the lanthanoid(II) cations is not square-antiprismatic but much better described as bicapped trigonal-prismatic. In contrast, quantum-chemical gas-phase calculations show the square-antiprismatic coordination polyhedron (point group S₈) to be energetically favored over the bicapped trigonal prism and the latter is not even a true local minimum. Obviously, hydrogen bonding and eventually other weak interactions have an impact on the observed bicapped trigonal-prismatic coordination sphere of the [M(NH₃)₈]²⁺ cations in the solid state.     

A Novel Beryllium Thiolate Resulting from N−Si Bond Cleavage: Liberation of Ammonia in the Reaction of Be[N(SiMe3)2]2 with HSPh

A side reaction leads to the product. In the synthesis of [{Be(SPh)₂(py)(NH₃)}₂{[18]crown-6}] ( 1 , py=pyridine) from [Be{N(SiMe₃)₂}₂] and HSPh, the coordinated ammonia molecules (see the structure of 1 in the picture) are formed in a competing reaction between liberated hexamethyldisilazane and the thiol.     

First Characterization of an Extended Ammonium‐Ammonia Complex [{NH4(NH3)4}+(μ‐NH3)2] in the Crystal Structure of [NH4(NH3)4][Co(C2B9H11)2] · 2 NH3

The compound [NH₄(NH₃)₄][Co(C₂B₉H₁₁)₂] · 2 NH₃ ( 1 ) was prepared by the reaction of Na[Co(C₂B₉H₁₁)₂] with a proton‐charged ion‐exchange resin in liquid ammonia. The ammoniate 1 was characterized by low temperature single‐crystal X‐ray structure analysis. The anionic part of the structure consists of [Co(C₂B₉H₁₁)₂]^‐ complexes, which are connected via C‐H···H‐B dihydrogen bonds. Furthermore, 1 contains an infinite equation/tex2gif-stack-2.gif[{NH₄(NH₃)₄}⁺(μ‐NH₃)₂] cationic chain, which is formed by [NH₄(NH₃)₄]⁺ ions linked by two ammonia molecules. The N‐H···N hydrogen bonds range from 1.92 to 2.71Å (DHA = Donor···Acceptor angles: 136‐176°). Additional N‐H···H‐B dihydrogen bonds are observed (H···H: 2.3‐2.4Å).     

Remarkable Reaction of Hetero-S-Block-Metal Amides with Molecular Oxygen: Cationic (NMNMg)2 Ring Products (M=Li or Na) with Anionic Oxo or Peroxo Cores

Deliberate treatment of solutions of amines with molecular oxygen has given rise to magnesium-substituted derivatives of classical alkali metal amide ring structures (NMNMg)₂ (M=Li or Na), but with oxo or peroxo cores. The picture shows the structure of the sodium compound [{(Me₃Si)₂N}₄Na₂Mg₂(O₂)_x(O)_y].     

Synthesis and Characterization of the Rubidium Thiophosphate Rb6(PS5)(P2S10) and the Rubidium Silver Thiophosphates Rb2AgPS4, RbAg5(PS4)2 and Rb3Ag9(PS4)4

The metal thiophosphates Rb₂AgPS₄ ( 2 ), RbAg₅(PS₄)₂ ( 3 ), and Rb₃Ag₉(PS₄)₄ ( 4 ) were synthesized by stoichiometric reactions, whereas Rb₆(PS₅)(P₂S₁₀) ( 1 ) was prepared with excess amount of sulfur. The compounds crystallize as follows: 1 monoclinic, P2₁/c (no. 14), a = 17.0123(7) Å, b = 6.9102(2) Å, c = 23.179(1) Å, β = 94.399(4)°; 2 triclinic, P$\bar{1}$ (no. 2), a = 6.600(1) Å, b = 6.856(1) Å, c = 10.943(3) Å, α = 95.150(2)°, β = 107.338(2)°, γ = 111.383(2)°; 3 orthorhombic, Pbca (no. 61), a = 12.607(1) Å, b = 12.612(1) Å, c = 17.759(2) Å; 4 orthorhombic, Pbcm (no. 57), a = 6.3481(2) Å, b = 12.5782(4) Å, c = 35.975(1) Å. The crystal structures contain discrete units, chains, and 3D polyanionic frameworks composed of PS₄ tetrahedral units arranged and connected in different manner. Compounds 1 – 3 melt congruently, whereas incongruent melting behavior was observed for compound 4 . 1 – 4 are semiconductors with bandgaps between 2.3 and 2.6 eV and thermally stable up to 450 °C in an inert atmosphere.     

Darstellung und Strukturaufklärung von Ammonium‐tetraamminlithium‐amidotrithiophosphat‐Ammoniak(1/1) (NH4) [Li(NH3)4] [P(NH2)S3] · NH3

Synthesis and Crystal Structure of Ammonium Tetraamminelithium Amidotrithiophosphate‐Ammonia(1/1)(NH₄)[Li(NH₃)₄][P(NH₂)S₃]·NH₃ Colourless crystals of (NH₄)[Li(NH₃)₄][P(NH₂)S₃]·NH₃ were prepared by the reduction of P₄S₁₀ with a solution of lithium in liquid ammonia. The X‐ray structure determination shows them to contain the pseudo‐tetrahedral amidotrithiophosphate anion [P(NH₂)S₃]²⁻ (point group C_S), which is the hitherto unknown final member of a series of previously characterized amidothiophosphates. The ammonium ion and the ammonia molecule of solvation form an diamminehydrogen(1+)‐ion N₂H₇⁺ with a short, nearly linear hydrogen bond of 2.864(3) Å.     

UF6 and UF4 in Liquid Ammonia: [UF7(NH3)]3− and [UF4(NH3)4]

From the reaction of uranium hexafluoride UF₆ with dry liquid ammonia, the [UF₇(NH₃)]^3? anion and the [UF₄(NH₃)₄] molecule were isolated and identified for the first time. They are found in signal‐green crystals of trisammonium monoammine heptafluorouranate(IV) ammonia (1:1; [NH₄]₃[UF₇(NH₃)] ? NH₃) and emerald‐green crystals of tetraammine tetrafluorouranium(IV) ammonia (1:1; [UF₄(NH₃)₄] ? NH₃). [NH₄]₃[UF₇(NH₃)] ? NH₃ features discrete [UF₇(NH₃)]^3? anions with a coordination geometry similar to a bicapped trigonal prism, hitherto unknown for U^IV compounds. The emerald‐green [UF₄(NH₃)₄] ? NH₃ contains discrete tetraammine tetrafluorouranium(IV) [UF₄(NH₃)₄] molecules. [UF₄(NH₃)₄] ? NH₃ is not stable at room temperature and forms pastel‐green [UF₄(NH₃)₄] as a powder that is surprisingly stable up to 147 °C. The compounds are the first structurally characterized ammonia complexes of uranium fluorides.     

The Heterometallic Clusters of Trivalent Rare Earth Metals of [Ln(OPh)6{Li(dme)}3], with Ln=Eu and Sm

Two new heterobimetallic phenoxide Ln^III–Li complexes of formula [Ln(μ₂‐OPh)₆{Li(dme)}₃] (Ln=Sm, Eu) have been synthesized and characterized using single‐crystal X‐ray diffraction. These two compounds are isostructural.     

Accuracy in the Isotope Dilution Mass Spectrometry of Uranium in Rubidium Uranium Sulphate Rb2U(SO4)3

Abstract

Problems encountered in the determination of uranium in rubidium uranium sulphate (Rb₂U(SO₄)₃) employing isotope dilution thermal ionisation mass spectrometry (ID-TIMS) are discussed. The positive bias of 0.2 to 0.3% in the determination of uranium in Rb₂U(SO₄)₃ by ID-TIMS with respect to the stoichiometric composition has been resolved by modifying the chemical exchange procedures. The concentration of uranium in Rb₂U(SO₄)₃ could be determined with an accuracy better than 0.1% employing the HClO₄ treatment for proper isotopic exchange between the spike and sample isotopes.     

Tetrahedral [Tt4]4– Zintl Anions Through Solution Chemistry: Syntheses and Crystal Structures of the Ammoniates Rb4Sn4·2NH3, Cs4Sn4·2NH3, and Rb4Pb4·2NH3

The crystalline isotypic solvates Rb₄Sn₄·2NH₃, Cs₄Sn₄·2NH₃, and Rb₄Pb₄·2NH₃ have been synthesized using the direct reduction of elemental tin or tetraphenyltin, respectively, with heavier alkali metals or the dissolution of the binary phase RbPb in liquid ammonia. These compounds contain the cluster ions [Sn₄]^4– or [Pb₄]^4– respectively. This is the first time that[Tt₄]^4– ions (Tt = tetrels) are detected as result of a solution reaction. The accommodation of the ammonia molecules, which build up ion‐dipole interactions to alkali metal cations, requires some modifications of the crystal structures compared to the binary phases RbSn, CsSn, and RbPb. The tetrahedral [Tt₄]^4– anions have a slightly lower coordination by Rb⁺ or Cs⁺ cations and, furthermore, the intercluster distances show a remarkable increase.     

As12Se44—: ein neuartiges Selenoarsenatanion mit einem Polyarsenkäfig in der Verbindung [Co(NH3)6]2As12Se4 · 12 NH3

As₁₂Se₄^4—: a New Selenoarsenate Anion with a Polyarsenic Cage in the Compound [Co(NH₃)₆]₂As₁₂Se₄ · 12 NH₃ Orange coloured crystals of [Co(NH₃)₆]₂As₁₂Se₄ · 12 NH₃ were prepared by the reduction of As₄Se₄ with a solution of sodium in liquid ammonia and subsequent precipitation with CoBr₂. The X‐ray structure determination shows them to contain the selenoarsenate anion As₁₂Se₄^4—, which consists of a central As₁₂‐cage with four exo‐bonded, formally negatively charged Se atoms. The structure of the As₁₂‐cage is equivalent to the main polyphosphorus building unit of a known organopolyphosphane and of tubular P₁₂ in the compound (CuI)₃P₁₂.     

A S8‐like [Sb8]8− Zintl Anion in the Ammoniate [K17(Sb8)2(NH2)] · 17.5NH3

The ammoniate [K₁₇(Sb₈)₂(NH₂)] · 17.5NH₃ was synthesized by reduction of antimony with potassium in liquid ammonia. Single crystals were isolated and characterized by low temperature X‐ray structure analysis. [K₁₇(Sb₈)₂(NH₂)] · 17.5NH₃ crystallizes in the space group P2₁/c (No. 14) with a = 12.976(1) Å, b = 24.536(1) Å, c = 22.858(1) Å and β = 99.17(1)°. The ammoniate contains crown‐shaped [Sb₈]^8? Zintl anions which are analogous to S₈ rings. The presence of amide NH₂^? as an additional anion is deduced from coordination observations and the close similarity of structural features to the structure of KNH₂.     

The First Organically Templated Layered Uranium(IV) Fluorides: (H3N(CH2)3NH3)U2F10⋅2 H2O, (H3N(CH2)4NH3)U2F10⋅3 H2O,and (H3N(CH2)6NH3)U2F10⋅2 H2O

A new series of layered organically templated uranium(IV ) fluorides has been exclusively synthesized under hydrothermal conditions. The unprecedented materials contain [U₂F₁₀]²⁻ anionic layers that are separated by charge balancing cationic templates and occluded water molecules (see structure depicted). The templates can be fully ion-exchanged for a variety of metals (Na⁺, K⁺, and Co²⁺) at room temperature.     

Zweidimensionale Polymere mit hydrophober Umhüllung: Kristallstrukturen der isostrukturellen Metallkomplexe [M{C6H4(SO2)2N}(H2O)] (M = K,Rb) und des strukturverwandten Ammoniumsalzes [(NH4){C6H4(SO2)2N}(H2O)]

Metal Salts of Benzene‐1,2‐di(sulfonyl)amine. 4. Hydrophobically Wrapped Two‐Dimensional Polymers: Crystal Structures of the Isostructural Metal Complexes [M{C₆H₄(SO₂)₂N}(H₂O)] (M = K, Rb) and of the Structurally Related Ammonium Salt [(NH₄){C₆H₄(SO₂)₂N}(H₂O)] The previously unreported compounds KZ · H₂O ( 1 ), RbZ · H₂O ( 2 ) and NH₄Z · H₂O ( 3 ), where Z^– is Ndeprotonated ortho‐benzenedisulfonimide, are examples of layered inorgano‐organic solids, in which the inorganic component is comprised of metal or ammonium cations, N(SO₂)₂ groups and water molecules and the outer regions are formed by the planar benzo rings of the anions. The metal complexes 1 and 2 were found to be strictly isostructural, whereas 3 is structurally related to them by a non‐crystallographic mirror plane ( 1 – 3 : monoclinic, space group P2₁/c, Z = 4; single crystal X‐ray diffraction at low temperatures). In each structure, the five‐membered 1,3,2‐dithiazolide heterocycle possesses an envelope conformation, the N atom lying about 40 pm outside the mean plane of the S–C–C–S moiety. The metal complexes feature two‐dimensional coordination networks interwoven with O–H…O hydrogen bonds originating from the water molecules. The metal centres adopt an irregular nonacoordination formed by five sulfonyl O atoms, two N atoms and two μ₂‐bridging water molecules; each M⁺ is connected to four different anions. When NH₄⁺ is substituted for M⁺, the metal–ligand bonds are replaced by N⁺–H…O hydrogen bonds, but the general topology of the lamella is not affected. In the three structures, the lipophilic benzo groups protrude obliquely from the surfaces of the polar lamellae and display marked interlocking between adjacent layers.     

Tieftemperatur‐Oxidation in flüssigem Ammoniak: [Eu2(Ind)4(NH3)6], das erste Indolat eines Selten‐Erd‐Elementes

Low‐Temperature Oxidation in Liquid Ammonia: [Eu₂(Ind)₄(NH₃)₆], the First Indolate of a Rare Earth Element Intensively yellow to orange coloured, transparent crystals of [Eu₂(Ind)₄(NH₃)₆] were obtained by low‐temperature oxidation of europium metal with indole (C₈H₆NH) in liquid ammonia at —50 °C and subsequent melting of the reaction mixture in excess indole at 120 °C. [Eu₂(Ind)₄(NH₃)₆] has a dimeric structure and contains divalent Eu. The coordination sphere around the europium atoms consists of five N atoms of two cisoid indolate anions and three NH₃ molecules as well as an η⁵‐coordinating π‐system of another indolate ligand, bridging to the next Eu atom with an sp²‐orbital.     

[Si4]4– and [Si9]4– Clusters Crystallized from Liquid Ammonia Solution – Synthesis and Characterization of K8[Si4][Si9]·(NH3)14.6

The extraction of the silicide K₁₂Si₁₇ with liquid ammonia in the presence of a sequestering agent and AuPPh₃Cl or Zn(Cp*)₂ led to crystals of the solvate compound K₈[Si₄][Si₉] · (NH₃)_14.6, which was characterized by single‐crystal X‐ray diffraction. It is the first compound with an isolated and ligand‐free [Si₄]^4– cluster obtained from solution. It also contains one [Si₉]^4– cluster per formula unit, whereas the precursor K₁₂Si₁₇ is built from [Si₄]^4– and [Si₉]^4– clusters with a 2:1 ratio.