Bildung des „superoktaedrischen”︁ Heteropolyanions [Ni(TaF6)6]4− bei der Oxidation von Tantal mit Ammoniumfluorid an der Monel-Wand

Formation of the “Superoctahedral” Heteropolyanion [Ni(TaF₆)₆]^4? through Oxidation of Tantalum with Ammonium Fluoride at the Monel-Container Wall A few single crystals of (NH₄)₄[Ni(TaF₆)₆] are obtained besides (NH₄)[TaF₆] as the main product of the reaction of (NH₄)F with tantalum powder in an He-are-welded Monel metal container at 400°C. The crystal structure (trigonal, R-3c (Nr. 167), Z = 6, a = 1723,0(2); c = 2166,6(2) pm; R1 = 0,0303, _WR2 = 0,0609) contains the superoctahedral heteropolyanion [Ni(TaF₆)₆]^4? and (NH₄)⁺ ions; it may be recognized as a derivative structure of the K₄CdCl₆ type according to (NH₄)₄[Ni(TaF₆)₆]?K₄[Cd(Cl)₆].     

Derivate des Flußspat-Typs: [Fe(NH3)6][TaF6]2 und [Ni(NH3)6][TaF6]2

Derivatives of the Fluorite Type: [Fe(NH₃)₆][TaF₆]₂ and [Ni(NH₃)₆][TaF₆]₂ Light blue single crystals of [Fe(NH₃)₆][TaF₆]₂ and [Ni(NH₃)₆][TaF₆]₂ are obtained from 36 : 1 : 6 molar mixtures of (NH₄)F, iron/nickel and tantalum powders, respectively, in sealed Monel metal ampoules at 400 °C. They both crystallize isotypic with [Co(NH₃)₆][PF₆]₂ (cubic, Fm-3m, Z = 4, a = 1259.0(2)/1260.4(2) pm) in a structure that can be derived from the basic fluorite-type of structure according to [Ca][F]₂≡[Fe(NH₃)₆][TaF₆]₂, for example.     

First examples of cyano-bridged complexes based on a novel cluster anion [Re<Subscript>12</Subscript>C<Subscript>17</Subscript>(CN)<Subscript>6</Subscript>]<Superscript>6−</Superscript>

Two cyano-bridged compounds of novel dodecanuclear cluster anion [Re₁₂CS₁₇(CN)₆] with Ni²⁺ cations were synthesized, namely, one-dimensional polymer of the composition [{Ni(NH₃)₄} {Ni(NH₃)₅}₂Re₁₂CS₁₇(CN)₆] · 7H₂O (I) with a chain structure and [Ni(NH₃)₆]₃[{Ni(NH₃)₄}₃ {Re₁₂CS₁₇(CN)₆}₂] · 21H₂O (II), containing the anionic dimeric complex [{Ni(NH₃)₄}₃ {Re₁₂CS₁₇(CN)₆}₂]^6?. The structures of both compounds were established by X-ray diffraction analysis. Crystals I are monoclinic, space group P2/n, a = 15.321(3), b = 12.635(2), c = 15.448(3) Å, β = 100.242(3)°, V = 2942.8(8) ų, Z = 2. Crystals II are trigonal, space group R3, a = b = 19.7987(14), c = 28.8642(18) Å, V = 9798.6(12) ų, Z = 3.     

Synthese und Kristallstrukturen von NH4[Si(NH3)F5] und [Si(NH3)2F4]

Synthesis and Crystal Structures of NH₄[Si(NH₃)F₅] and [Si(NH₃)₂F₄] Single crystals of NH₄[Si(NH₃)F₅] and [Si(NH₃)₂F₄] are obtained by reaction of silicon powder with NH₄HF₂ in sealed Monel ampoules at 400°C. NH₄[Si(NH₃)F₅] crystallizes with the tetragonal space group P4/n (no. 85) with a = 614.91(7) pm, c = 721.01(8) pm, Z = 2. Characteristic for the structure is the anionic octahedron [Si(NH₃)F₅]^?. Si(NH₃)₂F₄ crystallizes with the monoclinic space group P2₁/c (no. 14) with a = 506.9(1) pm, b = 728.0(1) pm, c = 675.9(1), β = 93,21(2)°, Z = 2. Trans-[Si(NH₃)₂F₄] molecules are characteristic for this structure.     

IV Dodekaedrische [Mo(CN)8]‐Koordination in den cyanoverbrückten Cobalt‐ und Nickel‐Amminkomplexen MII2(NH3)8[Mo(CN)8] · 1,5 H2O (MII = Co,Ni) und Ni2(NH3)9[Mo(CN)8] · 2 H2O

Crystal Structures of Octacyanomolybdates(IV). IV Dodecahedral [Mo(CN)₈] Coordination of the Cyano‐Bridged Cobalt and Nickel Ammin Complexes M^II₂(NH₃)₈[Mo(CN)₈] · 1.5 H₂O (M^II = Co, Ni) and Ni₂(NH₃)₉[Mo(CN)₈] · 2 H₂O At single crystals of the hydrated cyano complexes Co₂(NH₃)₈[Mo(CN)₈] · 1.5 H₂O (a = 910.0(4), b = 1671(2), c = 1501(1) pm, β = 93.76(6)°) and Ni₂(NH₃)₈[Mo(CN)₈] · 1.5 H₂O (a = 899.9(9), b = 1654.7(4), c = 1488(1) pm, β = 94.01°), isostructurally crystallizing in space group P2₁/c, Z = 4, and of trigonal Ni₂(NH₃)₉[Mo(CN)₈] · 2 H₂O (a = 955.1(1), c = 2326.7(7) pm, P3₁, Z = 3), X‐ray structure determinations were performed at 168 resp. 153 K. The [Mo(CN)₈]^4– groups of the three compounds, prepared at about 275 K and easily decomposing, show but slightly distorted dodecahedral coordination (mean distances Mo–C: 216.3, 215.4 and 216.1 pm). Within the monoclinic complexes the anions twodimensionally form cyano bridges to the ammin cations [M(NH₃)₄]²⁺ and are connected with the resulting [MN₆] octahedra (Co–N: 215.1 pm, Ni–N: 209.8 pm) into strongly puckered layers. The trigonal complex exhibits a chain structure, as one [Ni(NH₃)₅]²⁺ cation is only bound as terminal octahedron (Ni–N: 212.0 pm). Details and the influence of hydrogen bridges are discussed.     

High Nuclearity Antimonato‐Polyoxovanadate Cluster {V15Sb6O42} as a Synthon for the Solvothermal in situ Generation of α‐ and β‐{V14Sb8O42} Isomers

New heteroatom polyoxovanadates (POVs) were synthesized by applying a water‐soluble high‐nuclearity cluster as new synthon. The [V₁₅Sb₆O₄₂]^6? cluster shell exhibiting D₃ symmetry was in situ transformed into completely different cluster shells, namely, the α‐[V₁₄Sb₈O₄₂]^4? isomer with D_2d and the β‐[V₁₄Sb₈O₄₂]^4? isomer with D_2h symmetry. The solvothermal reaction of {Ni(en)₃}₃[V₁₅Sb₆O₄₂(H₂O)_x] ? 15 H₂O (x=0 or 1; en=ethylenediamine) in water led to the crystallization of [{Ni(en)₂}₂V₁₄Sb₈O₄₂] ? 5.5 H₂O containing the β‐isomer. The addition of [Ni(phen)₃](ClO₄)₂ ? 0.5 H₂O (phen=1,10‐phenanthroline) to the reaction slurry gave the new compound {Ni(phen)₃}₂[V₁₄Sb₈O₄₂] ? phen ? 12 H₂O with the α‐isomer. Both transformation reactions are complex due the change of symmetry, the chemical composition, and rearrangement of the VO₅ square pyramids and Sb₂O₅ handle‐like moieties.     

Cyano-bridged complexes based on re tetrahedral cluster anions, Ni2+ cations, and polydentate amines

Interaction of the tetrahedral chalcocyanide cluster anionic complexes of Re, K₄[Re₄Q₄(CN)₁₂] (Q=S, Se, Te), with Ni²⁺ cationic complexes with polydentate amines, such as ethylenediamine (En), diethylenetriamine (Dien), or triethylenetetraamine (Trien) was used to synthesize six novel complexes: [Ni(NH₃)₄(En)][{Ni(NH₃)(En)₂}Re₄Te₄(CN)₁₂] · 2H₂O, [{Ni(En)₂}₂Re₄Se₄(CN)₁₂] · 3.5H₂O, [Ni(NH₃)₃(Dien)]₂[Re₄Se₄(CN)₁₂] · 5.5H₂O, [{Ni(NH₃)₂(Dien)}₂Re₄Te₄(CN)₁₂] · 2.5H₂O. [Ni(NH₃)₂(Trien)][{Ni(NH₃)(Trien)}Re₄Se₄(CN)₁₂] · 2.5H₂O, [{Ni(Trien)}₂Re₄S₄(CN)₁₂] · 3H₂O. The complexes were studied by single-crystal X-ray diffraction analysis.     

Kristallstruktur von (NH4)3SnF7: Ein Doppelsalz gemäß (NH4)3[SnF6]F und kein (NH4)4SnF8

Crystal Structure of (NH₄)₃SnF₇: A Double Salt According to (NH₄)₃[SnF₆]F and not (NH₄)₄SnF₈ (NH₄)₃SnF₇ is obtained as colourless single crystals from the reaction of NH₄HF₂ with tin powder at 300°C. The crystal structure (cubic, Pm3m, Z = 1, a = 602.5(1) pm at 293 K; a = 598.0(1) pm at 100 K) contains [SnF₆]^2? octahedra and lonesome F^? ions surrounded by NH₄⁺ cations only; it may be considered as a derivative of the Cu₃Au-type of structure according to Cu₃[Au]□ ?(NH₄)₃[SnF₆]F. The F^? ions of the [SnF₆]^2? octahedra with their Sn⁴⁺ centre in the origin of the unit cell at m3m are disordered in different ways at 293 and 100 K, respectively.     

Binary salt of a palladium(II) complex with (phosphonomethyl)phosphonic (medronic) acid comprising `handbell‐like' [Pd{μ‐CH2(PO3)2}]3 units

The asymmetric unit of the title compound, dipotassium bis[hexaaquanickel(II)] tris(μ₂‐methylenediphosphonato)tripalladium(II) hexahydrate, K₂[Ni(H₂O)₆]₂[Pd₃{CH₂(PO₃)₂}₃]·6H₂O, consists of half a {[Pd{CH₂(PO₃)₂}]₃}⁶⁻ anion [one Pd atom (4e) and a methylene C atom (4e) occupy positions on a twofold axis] in a rare `handbell‐like' arrangement, with K⁺ and [Ni(H₂O)₆]²⁺ cations to form the neutral complex, completed by three solvent water molecules. The {[Pd{CH₂(PO₃)₂}]₃}⁶⁻ units exhibit close Pd...Pd separations of 3.0469 (4) Å and are packed via intermolecular C—H...Pd hydrogen bonds. The [KO₉] and [NiO₆] units are assembled into sheets coplanar with (011) and stacked along the [100] direction. Within these sheets there are [K₄Ni₄O₈] and [K₂Ni₂O₄] loops. Successive alternation of the sheets and [Pd{CH₂(PO₃)₂}]₃ units parallel to [001] produces the three‐dimensional packing, which is also supported by a dense network of hydrogen bonds involving the solvent water molecules.     

Potassium gallium hydrogenphosphate fluoride,K2Ga[H(HPO4)2]F2

Hydrothermally synthesized dipotassium gallium {hydrogen bis[hydrogenphosphate(V)]} difluoride, K₂Ga[H(HPO₄)₂]F₂, is isotypic with K₂Fe[H(HPO₄)₂]F₂. The main features of the structure are ([Ga{H(HPO₄)₂}F₂]²⁻)_n columns consisting of centrosymmetric Ga(F₂O₄) octahedra [average Ga—O = 1.966 (3) Å and Ga—F = 1.9076 (6) Å] stacked above two HPO₄ tetrahedra [average P—O = 1.54 (2) Å] sharing two O‐atom vertices. The charge‐balancing seven‐coordinate K⁺ cations [average K—O,F = 2.76 (2) Å] lie in the intercolumn space, stabilizing a three‐dimensional structure. Strong [O...O = 2.4184 (11) Å] and medium [O...F = 2.6151 (10) Å] hydrogen bonds further reinforce the connections between adjacent columns.     

Synthesis and crystal structure of the octahedral cyano-bridged cluster complex β-[{Ni(NH3)5}2{Re6Te8(CN)6}]·4H2O

The rhenium cyano-bridged cluster complex with a composition of β-[{Ni(NH₃)₅}₂{Re₆Te₈(CN)₆}]−4H₂O is obtained and structurally characterized. The compound pound crystallizes in the P $ P\bar 1 $ P\bar 1 triclinic space group with the unit cell parameters: a = 9.997(2) ?, b = 10.423(2) ?, c = 11.714(2) ?, α = 100.92(3)°, β = 111.87(3)°, γ = 98.05(3)°, V = 1082.1(4) ?³, Z = 1, d _calc = 4.072 g/cm³. The rhenium atoms of the {Re₆Te₈} cluster core are coordinated by CN ligands to form the [Re₆Te₈(CN)₆]⁴⁻ cluster; two nitrogen atoms of CN ligands trans-positioned with respect to each other are coordinated to Ni atoms in the {Ni(NH₃)₅}²⁺ fragments to form the molecular complexes of [{Ni(NH₃)₅}₂}Re₆Te₈(CN)₆}]. The crystal structure is the H-bonded packing of these molecular complexes and crystallization water molecules.     

Crystal structure of the ionic bioctahedral cluster complex [Ni(NH3)6]2.5NH4[Re12CS17(CN)6]·8.5H2O

A rhenium cluster complex [Ni(NH₃)₆]_2.5·NH₄[Re₁₂CS₁₇(CN)₆]·8.5H₂O is obtained and structurally described. The compound crystallizes in the triclinic space group P-1 with the unit cell parameters: a = 11.0856(13) Å, b = 15.242(2) Å, c = 21.232(3) Å, α = 90.158(4)°, β = 97.439(4)°, γ = 90.051(4)°, V = 3557.3(8) ų, Z = 2, d _calc = 3.287 g/cm³. The crystal structure represents a packing of [Ni(NH₃)₆]²⁺ and NH₄ ⁺ cations, [Re₁₂CS₁₇(CN)₆]^6? cluster anions, and crystallization water molecules bound by a system of hydrogen bonds.     

Über die Kristallstrukturen der Cyanokomplexe [Co(NH3)6][Fe(CN)6], [Co(NH3)6]2[Ni(CN)4]3 · 2 H2O und [Cu(en)2][Ni(CN)4]

On the Crystal Structures of the Cyano Complexes [Co(NH₃)₆][Fe(CN)₆], [Co(NH₃)₆]₂[Ni(CN)₄]₃ · 2 H₂O, and [Cu(en)₂][Ni(CN)₄] Of the three title compounds X‐ray structure determinations were performed with single crystals. [Co(NH₃)₆][Fe(CN)₆] (a = 1098.6(6), c = 1084.6(6) pm, R3, Z = 3) crystallizes with the CsCl‐like [Co(NH₃)₆][Co(CN)₆] type structure. [Co(NH₃)₆]₂[Ni(CN)₄]₃ · 2 H₂O (a = 805.7(5), b = 855.7(5), c = 1205.3(7) pm, α = 86.32(3), β = 100.13(3), γ = 90.54(3)°, P1, Z = 1) exhibits a related cation lattice, the one cavity of which is occupied by one anion and 2 H₂O, whereas the other contains two anions parallel to each other with distance Ni…Ni: 423,3 pm. For [Cu(en)₂][Ni(CN)₄] (a = 650.5(3), b = 729.0(3), c = 796.5(4) pm, α = 106.67(2), β = 91.46(3), γ = 106.96(2)°, P1, Z = 1) the results of a structure determination published earlier have been confirmed. The compound is weakly paramagnetic and obeys the Curie‐Weiss law in the range T < 100 K. The distances within the complex ions of the compounds investigated (Co–N: 195.7 and 196.4 pm, Ni–C: 186.4 and 186.9 pm, resp.) and their hydrogen bridge relations are discussed.     

Darstellung,Kristallstruktur, thermischer Abbau und Schwingungsspektren von [Co(NH3)6]2[Be4O(CO3)6] · 10 H2O

Preparation, Crystal Structure, Thermal Decomposition, and Vibrational Spectra of [Co(NH₃)₆]₂[Be₄O(CO₃)₆] · 10 H₂O [Co(NH₃)₆]₂[Be₄O(CO₃)₆] · 10 H₂O is a suitable compound for the quantitative determination of beryllium. It can be obtained by reaction of aqueous solutions of carbonatoberyllate with [Co(NH₃)₆]Cl₃. The crystal structure (trigonal‐rhombohedral, R3c (Nr. 161), a = 1071,6(1) pm, c = 5549,4(9) pm, V_EZ = 5519(1) · 10⁶ pm³, Z = 6, R1(I ≥ 2σ(I)) = 0,037, wR2(I ≥ 2σ(I)) = 0,094) contains [Co(NH₃)₆]³⁺‐ and [Be₄O(CO₃)₆]^6–‐ions, which are directly hydrogen bonded as well as with water molecules. The complex cations and anions occupy the positions of a distorted anti‐CaF₂‐type. The thermal decomposition, IR and Raman spectra are presented and discussed.     

A re-interpretation of the crystal structure of ‘(NH4)2(NH3)[Ni(NH3)2Cl4]’ in terms of (NH4)2−2z[Ni(NH3)2]z[Ni(NH3)2Cl4]

A re-interpretation and re-evaluation of single-crystal X-ray diffraction data of a previously reported ‘(NH₄)₂(NH₃)[Ni(NH₃)₂Cl₄]’ (J. Solid State Chem. 162 (2001) 254) give a new formula (NH₄)_2−2z[Ni(NH₃)₂]_z[Ni(NH₃)₂Cl₄] with z=0.152. This new formula results from defects in an idealized ‘(NH₄)₂[Ni(NH₃)₂Cl₄]’ basic structure, where two adjacent NH₄⁺ cations are replaced by one Ni(NH₃)₂²⁺ unit. Cl⁻ anions from the basic structure complete the coordination sphere of the new Ni²⁺ to [Ni(NH₃)₂Cl₄]²⁻.     

Zwei Fluoridborate des Gadoliniums: Gd2F3[BO3] und Gd3F3[BO3]2

Two Fluoride Borates of Gadolinium: Gd₂F₃[BO₃] and Gd₃F₃[BO₃]₂ By flux‐supported solid‐state reaction of Gd₂O₃ and GdF₃ with B₂O₃ (flux: CsCl, molar ratio: 1 : 1 : 1 : 6, sealed tantalum capsule, 700 °C, 7 d) the new gadolinium fluoride borate Gd₂F₃[BO₃] (monoclinic, P2₁/c; a = 1637.2(1), b = 624.78(4), c = 838.04(6) pm, β = 93.341(8)°; V_m = 64.418(6) cm³/mol, Z = 8) was obtained as colourless, prismatic, face‐rich single crystals. The four crystallographically different Gd³⁺ cations (CN = 9) are all capped square‐antiprismatically surrounded by fluoride and oxide anions, in which the latter represent always components of isolated trigonal planar [BO₃]^3— anions. The six crystallographically independent F^— anions all reside in more or less planar coordination of three Gd³⁺ cations. Thus the constitution of Gd₂F₃[BO₃] can be described as a sequence of alternating layers each of the composition Gd[BO₃] and GdF₃ parallel (100), respectively. The crystal structures of Gd₂F₃[BO₃] and the shortly published Gd₃F₃[BO₃]₂ (monoclinic, C2/c; a = 1253.4(1), b = 623.7(1), c = 836.0(1) pm, β = 97.404(6)°; V_m = 97.571(9) cm³/mol, Z = 4) are compared with each other. Due to the structural analogies between these two gadolinium fluoride borates, a disorder model of the boron atoms frequently found for Gd₂F₃[BO₃] is able to be transferred to Gd₃F₃[BO₃]₂ as well.     

Group 6 Hexacarbonyls as Ligands for the Silver Cation: Syntheses,Characterization, and Analysis of the Bonding Compared with the Isoelectronic Group 5 Hexacarbonylates

The syntheses of the two novel complexes [Ag{Mo/W(CO)₆}₂]⁺[F-{Al(OR^F)₃}₂]⁻ (R^F=C(CF₃)₃) are reported along with their structural and spectroscopic characterization. The X-ray structure shows that three carbonyl ligands from each M(CO)₆ fragment bend towards the silver atom within binding Ag−C distance range. DFT calculations of the free cations [Ag{M(CO)₆}₂]⁺ (M=Cr, Mo, W) in the electronic singlet state give equilibrium structures with C₂ symmetry with two bridging carbonyl groups from each hexacarbonyl ligand. Similar structures with C₂ symmetry (M=Nb) and D₂ symmetry (M=V, Ta) are calculated for the isoelectronic group 5 anions [Ag{M(CO)₆}₂]⁻ (M=V, Nb, Ta). The electronic structure of the cations is analyzed with the QTAIM and EDA-NOCV methods, which provide detailed information about the nature of the chemical bonds between Ag⁺ and the {M(CO)₆}₂^q (q = −2, M = V, Nb, Ta; q = 0, M = Cr, Mo, W) ligands.     

Synthese und Struktur von Ammin- und Amidokomplexen des Iridiums

Synthesis and Structure of Ammine and Amido Complexes of Iridium The reaction of (NH₄)₂[IrCl₆] with NH₄Cl at 300 °C in a sealed glass ampoule yields the iridium(III) ammine complex (NH₄)₂[Ir(NH₃)Cl₅], which crystallizes isotypically with K₂[Ir(NH₃)Cl₅] in the orthorhombic space group Pnma with Z = 4, and a = 1350.0(2); b = 1028.5(3); c = 689.6(2) pm. The reaction of (NH₄)₂[IrCl₆] with NH₃ at 300 °C, however, gives the already known [Ir(NH₃)₅Cl]Cl₂ beside a small amount of [Ir(NH₃)₄Cl₂]Cl₂. In pure form [Ir(NH₃)₅Cl]Cl₂ is obtained by ammonolysis of (NH₄)₂[Ir(NH₃)Cl₅] at 300 °C with NH₃. [Ir(NH₃)₄Cl₂]Cl₂ crystallizes triclinic (P1, Z = 1, a = 660,2(3); b = 680,4(3); c = 711,1(2) pm; α = 103,85(2)°, β = 114,54(3)°, γ = 112,75(2)°). The structure contains Cl^– anions and [Ir(NH₃)₄Cl₂]²⁺ cations with a trans position of the Cl atoms. Upon reaction of [Ir(NH₃)₅Cl]Cl₂ with Cl₂ one ammine ligand is eliminated yielding [Ir(NH₃)₄Cl₂]Cl, which is transformed to orthorhombic [Ir(NH₃)₄(OH₂)Cl]Cl₂ (Pnma, Z = 4, a = 1335,1(3); b = 1047,9(2); c = 673,4(2) pm) by crystallization from water. In the octahedral complex [Ir(NH₃)₄(OH₂)Cl]²⁺ the four ammine ligands have an equatorial position, whereas the Cl atom and the aqua ligand are arranged axial. Oxidation of (NH₄)₂[Ir(NH₃)Cl₅] with Cl₂ at 330 °C affords the tetragonal Ir^IV complex (NH₄)[Ir(NH₃)Cl₅] (P4nc, Z = 2, a = 702.68(5); c = 912.89(9) pm). Its structure was determined using the powder diagram. Oxidation of (NH₄)₂[Ir(NH₃)Cl₅] with Br₂ in water, on the other hand, gives (NH₄)₂[IrBr₆] crystallizing in the K₂[PtCl₆] type. Oxidation of (PPh₄)₂[Ir(NH₃)Cl₅] with PhI(OAc)₂ in CH₂Cl₂ affords the Ir^V amido complex (PPh₄)[Ir(NH₂)Cl₅].     

Die Einwirkung von Ammoniumfluorid auf Scandium: Synthese und Kristallstrukturen von (NH4)3[ScF6] und [Cu(NH3)4]3[ScF6]2

Action of Ammonium Fluoride on Scandium: Synthesis and Crystal Structures of (NH₄)₃[ScF₆] and [Cu(NH₃)₄]₃[ScF₆]₂ The action of (NH₄)F on scandium in copper ampoules yields either (NH₄)₃[ScF₆] or ScF₃ and a small quantity of [Cu(NH₃)₄]₃[ScF₆]₂, respectively, depending upon the molar ratio of the educts (NH₄)F : Sc (6 : 1 and 4 : 1, respectively) and temperature. (NH₄)₃[ScF₆] crystallizes with the cryolite type of structure: monoclinic, P2₁/n, Z = 2; a = 650.0(2); b = 651.4(2); c = 949.0(2) pm; β = 90.40(2)°, [Cu(NH₃)₄]₃[ScF₆]₂ is triclinic, P‐1, Z = 1; a = 821.1(2); b = 821.2(2); c = 822.7(2) pm; α = 90.04(3); β = 90.00(3); γ = 90.16(3)°. In its chemical behaviour against (NH₄)F, scandium parallels aluminium rather than gallium.     

Metallampullen als Mini‐Autoklaven: Synthese und Kristallstrukturen der Ammoniakate [Al(NH3)4Cl2][Al(NH3)2Cl4] und (NH4)2[Al(NH3)4Cl2][Al(NH3)2Cl4]Cl2

Metal Ampoules as Mini‐Autoclaves: Syntheses and Crystal Structures of [Al(NH₃)₄Cl₂][Al(NH₃)₂Cl₄] and (NH₄)₂[Al(NH₃)₄Cl₂][Al(NH₃)₂Cl₄]Cl₂ The salts [Al(NH₃)₄Cl₂]⁺[Al(NH₃)₂Cl₄]^–≡AlCl₃ · 3 NH₃ ( 1 ) and (NH₄⁺)²[Al(NH₃)₄Cl₂]⁺[Al(NH₃)₂Cl₄]^–(Cl^–)₂≡ AlCl₃ · 3 NH₃ · (NH₄)Cl ( 2 ) have been obtained as single crystals during the reactions of aluminum and aluminum trichloride, respectively, with ammonium chloride in sealed Monel metal containers. The crystal structure of 1 was determined again [triclinic, P‐1; a = 574.16(10); b = 655.67(12); c = 954.80(16) pm; α = 86.41(2); β = 87.16(2); γ = 84.89(2)°], that of 2 for the first time [monoclinic, I2/m; a = 657.74(12); b = 1103.01(14); c = 1358.1(3) pm; β = 103.24(2)°].