Zur Kenntnis des Verhaltens der Oxidsulfate der Seltenen Erden gegen Chlorwasserstoff. III. Darstellung und thermisches Verhalten der Chloridsulfate der Seltenen Erden

Treatment of chlorination products of rare earths oxidesulphates with methanol yields chloride-sulphates M^IIIClSO₄ as residues. Thermal decomposition of chloride-sulphates yields oxide-sulphates MO₂SO₄; as intermediates, mixtures of the composition MO₂SO₄? M(SO₄)₃ are obtained.     

Zur Kenntnis des Verhaltens der Oxidsulfate der Seltenen Erden gegen Chlorwasserstoff. I. Umsetzung der Oxidsulfate einiger Seltener Erdmetalle mit Chlorwasserstoff

Reactions of the oxide sulphates M₂^IIIO₂SO₄ of La, Pr, Nd, Sm, Gd, Dy, Er, Yb and Y with hydrogen chloride between 450 and 600°C are described. The temperature dependence of reaction course is comparable with that of rare earth's oxides reactions with hydrogen chloride.     

19F-NMR-spektroskopischer Nachweis und Berechnung der statistischen Bildung der gemischten Clusteranionen [(Mo6BrCl)F]2−, n = 0 – 8

¹⁹F NMR Spectroscopic Evidence and Calculation of the Statistical Formation of Mixed Cluster Anions [(Mo₆Br Cl )F ]^2?, n = 0 – 8 The complete system of the innersphere mixed clusters (Mo₆BrCl)⁴⁺ is formed by exchange of innersphere bound Clⁱ against outersphere bound Br^a on tempering the solid [(Mo₆Cl)Br] at 500°C for 16 h. After conversion with conc. HCl into (H₃O)₂[(Mo₆BrCl)Cl] and precipitation of the outer Cl^a with AgBF₄ in ethanol, treatment with tetrabutylammonium(TBA)fluoride yields (TBA)₂ [(Mo₆BrCl)F], a mixture of 22 different species. According to the sets of chemical equivalent fluorine atoms in total 55 ¹⁹F nmr signals are expected, which are really observed in the high resolution 1D-¹⁹F-nmr spectrum. Using increments of chemical shifts, peak intensities and multiplet structures as well as the 2D-¹⁹F/¹⁹F-COSY spectrum the complete and unambiguous assignment of all resonances is achieved. From the measured integral intensities the distribution of the different compounds is determined, revealing statistical formation of the geometrical isomers.     

Über hexagonale Perowskite mit Kationenfehlstellen. XVI Die rhomboedrischen 12 L-Stapelvarianten Ba3AIIIM□O12 mit MV = Nb,Ta

On Hexagonal Perovskites with Cationic Vacancies. XVI. Rhombohedral 12 L-Stacking Polytypes Ba₃A^IIIM □O₁₂ with M^V = Nb, Ta The white quaternary oxides Ba₃LaM□O₁₂ with M^V = Nb, Ta belong to the group of hexagonal perovskites with cationic vacancies. They crystallize in a rhombohedral 12 L-structure (sequence (hhcc)₃; space group R3 m) with a = 5.75₁ Å; c = 28.1₁ Å (M^V = Nb); a = 5.74₆ Å; c = 28.2₀ Å (Ta) and Z = 3. Signs for the formation of isotypic compounds with A^III = Pr, Nd could be obtained as well.     

Strukturbestimmungen an geordneten Perowskiten des Typs Ba2BMVIO6

Determination of Structures of Ordered Perovskites of the Ba₂B M^VIO₆ Type Intensity calculations on powder patterns of Ba₂Y□_0.33M^VIO₆ with M^VI = U, W, Te und Ba₂Gd_0.67□_0.33UO₆ lead for the space group Fm3m/O with 8 Ba in 8c, 8/3 B^III and 4/3 □ in 4b, 4 M^VI in 4a and 24 O in 24e to R values between 4.3 and 7.6%. Two further models are discussed.     

Cs4[Sc6C]Cl13 und Cs4[Pr6(C2)]I13 — zwei Beispiele für das fehlende Bindeglied bei der Verknüpfung der Baueinheiten [M6Z]XX

Cs₄[Sc₆C]Cl₁₃ and Cs₄[Pr₆(C₂)]I₁₃ — Two Examples for the Missing Link in the Connectivity of [M₆Z]X X Building Units Cs₄[Sc₆C]Cl₁₃ (tetragonal, I4₁/amd, a = 1 540.5(4), c = 1 017.9(7) pm, c/a = 0.661, Z = 4, R = 0.038, R_w = 0.026) and Cs₄[Pr₆(C₂)]I₁₃ (a = 1 804.9(3), c = 1 259.5(3) pm, c/a = 0.698, R = 0.106, R_w = 0.068) are obtained as green-black and blue-black single crystals with brass-like metallic lustre through metallothermic reduction of ScCl₃ and PrI₃, respectively, with cesium in the presence of carbon in sealed tantalum containers. The, overall, isotypic compounds contain isolated [Sc₆C] and [Pr₆(C₂)] clusters, respectively, that are surrounded by 18 halide (X) ligands (12 Xⁱ and 6 X^a; X = Cl or I). The connection is carried out via the motif [M₆Z]XXXX (M = Sc and Pr; Z = C and C₂, respectively) and is thereby the missing link of the motifs of connection for the composition A_x[M₆Z]X₁₃. Analogous interconnection of [TiO₆] octahedra is found in the anatase-type of structure of TiO₂.     

Mitteilung der Abteilung für Anorganische Chemie der IUPAC

Metal Complexes with Anionic Ligands of Elements of the Main Group IV. IV. Homogenous and Heterogenous Transition Metal Complexes of the Dichlorobromo-, Dibromochloro-, and Tribromostannide Ligands Monosubstituted complexes of the type [M(CO)₅SnBr_3?nCl_n]^? are formed if the hexacarbonyls of chromium, molybdenum, and tungsten are reacted with halogenostannide ions SnBr_3?nCl (n = 0, 1, 2). The reactions of dibenzene chromium and this stannide ions yield homogenous hexakis(trihalogenostannide)chromate(0) complexes [Cr(SnBr_3?nCl_n)₆]^6? (n = 1, 2). Both types of chromate(0) ions are isolated as salts with the cation [N(C₂H₅)₄]⁺. The behaviour of SnBr_3?nCl (n = 0–3) as ligands is discussed, the i. r. spectra of their metalcarbonyl derivatives are reported.     

Kinetics of the solvolysis of [Co(3Rpy)4Cl2]+ ions (R = Me or Et) in water and in water + methanol mixtures

Rates of solvolysis of ions [Co(3Rpy)₄Cl₂]⁺ with R = Me and Et have been measured over a range of temperatures for a series of water-rich water + methanol mixtures to investigate the effect of changes in solvent structure on the solvolysis of complexes presenting a largely hydrophobic surface to the solvent. The variation of the enthalpies and entropies of activation with solvent composition has been determined. A free energy cycle relating the free energy of activation in water to that in water + methanol is applied using free energies of transfer of individual ionic species from water into water + methanol. Data for the free energy of transfer of chloride ions ΔG(Cl^?) from both the spectrophotometric solvent sorting method and the TATB method for separating ΔG(salt) into ΔG(i) for individual ions are used: irrespective of the source of ΔG(Cl^?), in general, ?ΔG(Co(Rpy)₄Cl²⁺) > ?ΔG(Co(Rpy)₄Cl₂⁺), where Rpy = py, 4Mepy, 4Etpy, 3Etpy, and 3Mepy, showing that changes in solvent structure in water-rich water + methanol mixtures generally stabilize the cation in the transition state more than the cation in the initial state for this type of complex ion. A similar result is found when the free energy cycle is applied to the solvolysis of the dichloro (2,2′,2″-triaminotriethylamine)cobalt(III) ion. The introduction of a Me or Et group on the pyridine ring in [Co(Rpy)₄Cl₂]⁺ has little influence on the difference {ΔG(Co(Rpy)₄Cl²⁺)?ΔG(Co(Rpy)₄Cl₂⁺)} in water + methanol with the mol fraction of methanol < 0.20.     

Über Geordnete Perowskite mit Kationenfehlstellen. IX. Verbindungen vom Typ Sr2Sr1/4B□1/4WO6≙Sr8SrB□W4O24 (BIII  La,Pr, Nd,Sm – Tm,Y)

On Ordered Perovskites with Cationic Vacancies. IX. Compounds of the Type Sr₂Sr_1/4B □_1/4WO₆?Sr₈SrB ?W₄O₂₄ (B^III ? La, Pr, Nd, Sm–Tm, Y) The compounds Sr₂Sr_1/4B□_1/4WO₆?Sr₈SrB?W₄O₂₄ belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) ?:1). For the larger B^III ions (La, Pr, Nd, Sm–Dy) different ordering effects are observed. The perovskites with B^III ? Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (B^III ? Gd: a = 2X8.23₄ Å); LT modification: hexagonal perovskite stacking polytype (B^III ? Gd: a = 9.95₄ Å; c = 19.0₄ Å)). With the smaller B^III ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed.     

Über Hexagonale Perowskite mit Kationenfehlstellen. I. Verbindungen vom Typ Ba2B□2/3ReVIIO6

On Hexagonal Perovskites with Cationic Vacancies. I. Compounds of the Type Ba₂B □_2/3Re^VIIO₆ Compounds of Type Ba₂B□_2/3Re^VIIO₆ are formed with B^III = Sm? Gd Ho? Lu, Y, Sc, In (yellow); Tb (black-brown); Dy (yellow-orange). They crystallize with B^III = Sm? Lu, Y and Sc in a rhombohedral layer structure of 12 L-type (space group R3 m; sequence: cchhcchhcchh) with 6 formula units in the unit cell.     

Schwingungsspektren der Clusterverbindungen (M6X)X · 8 H2O,M = Nb,Ta; Xi = CI,Br; Xa = CI,Br, I

Vibrational Spectra of the Cluster Compounds (M₆X₁₂ⁱ) · 8H₂O, M = Nb, Ta; Xⁱ = Cl, Br; X^a = Cl, Br, I IR and, for the first time, Raman spectra at 80 K of the cluster compounds (M₆X)X · 8H₂O; M = Nb, Ta; Xⁱ = Cl, Br; X^a = Cl, Br, I, have been recorded, characterized by typical frequencies of the (M₆X) unit, which are only slightly influenced by the terminal X^a ligands. The most intense line with the depolarisation ≈? 0.2 in all Raman spectra is caused by inphase movement of all atoms and assigned to the symmetric metal-metal vibration v₁, observed for the clusters (Nb₆Cl) at 233–234, for (Nb₆Br) at 186–187, for (Ta₆Cl) at 199–203, and for (Ta₆Br) at 176–179 cm^?1. The IR spectra exhibit in the same series intense bands at 233, 204, 207, and 179 cm^?1, assigned to the antisymmetric metal-metal vibration. The metal-metal frequencies are significantly higher than discussed before. The tantalum clusters show on excitation with the krypton line 647.1 nm in the region of a d–d transition at 645 nm a resonance Raman effect with series of overtones and combination bands. In case of (Ta₆Br) another polarisized band is observed at 229 cm^?1 and assigned to the Ta? Brⁱ vibration v₂. From the progressions of v₁ and v₂ anharmonicity constants of about ?3 cm^?1 are calculated indicating a strong distortion of the potential curves.     

Neue Phosphate mit Eulytinstruktur,insbesondere Europium(II)-Verbindungen [1]

New Phosphates with Eulytine Structure, especially Europium(II) Compounds. A number of Eu(II) phosphates EuLn(PO₄)₃ have been prepared, where Ln? La, lanthanides, Y. All investigated compounds have colours from yellow to ockre and crystallize with the cubic structure of eulytine (Bi₄(SiO₄)₃). Eu(PO₄)₃ makes an exception, showing a lattice deformation to low symmetry. It converts to a cubic eulytine phase by partial oxydation. The peculiar run of the lattice constants of the Eu(II) compounds in the lanthanide series is compared with the behaviour of the analogous Sr, Pb, and Ba compounds. Moreover, the eulytine compounds Pb₃M^III(PO₄)₃ with M^III? V, Cr, Fe have been synthesized. Experiments with Ti^III yield solid solutions between Pb₃Ti^III(PO₄)₃ and Pb₇Ti^IV(PO₄)₆.     

Nitridsulfidchloride der Lanthanide: III. Synthese und Kristallstruktur von Pr5N3S2Cl2

Nitride Sulfide Chlorides of the Lanthanides. III. Synthesis and Crystal Structure of Pr₅N₃S₂Cl₂ By reacting praseodymium with sulfur, sodium azide and praseodymium trichloride in sealed, evacuated silica tubes (850°C, 7 d), the nitride sulfide chloride Pr₅N₃S₂Cl₂ is obtained in case of a 4:2:1:1 molar ratio of the reactants (Pr:S:NaN₃:PrCl₃). A slight excess of trichloride or the addition of NaCl as a flux supports the yield of brownish red, rod-shaped transparent crystals which prove to be stable against hydrolysis. The crystal structure (monoclinic, C2/m (no. 12), a = 1540.2(1), b = 400.92(3), c = 1656.3(1) pm, β = 101.24(1)°, Z = 4, R = 0.039, R_w = 0.028) was determined by means of X-ray single crystal data. Thus five crystallographically different cations (Pr³⁺) are present which with three distinct kinds of nitride anions (N^3?) build up two types of translationally commensurate chains from interconnected [NPr₄] tetrahedra. With an additional edge per “chain-link” in chain I, two single chains [NPr_3/3^ePr_1/1^t]³⁺ (?[NPr₂]³⁺) of cis-edge connected [NPr₄] tetrahedra (known from the Sm₄N₂S₃-type structure) are condensed into the double chain [(N1){(Pr1)_(2+2)/(2+2)^e,e(Pr2)_(2+1)/(2+1)^e,v}(N2)(Pr3)_1/1^t]³⁺ (?[N₂Pr₃]³⁺). Chain II consists of two single chains [NPr_2/2^vPr_2/1^t] ⁶⁺ (?[NPr₃]⁶⁺) of vertex-connected [NPr₄] tetrahedra (known from the Sm₃NS₃-type structure), which are condensed to the double chain [(N3)(Pr4)_2/2^e(Pr5)_2/2^v]³⁺ (?[NPr₂]³⁺) via an additional edge per “chain-link” too. Both types of chains are bundled along [010] like a closest packing of rods. Four crystallographically different but by X-ray diffraction indistinguishable anions S^2? and Cl^? hold both cationic double chains together and also adjust the charge balance in a molar ratio of 1 : 1.     

Kinetic characteristics of chloride-assisted oxidative dealkylation of alkylcobalamins

The recent experiments on the chloride-assisted dealkylation of alkylcobalamins by a variety of oxidants (IrCl, AuCl, Fe(H₂O)₅Cl²⁺, and PtCl), which are scattered in several previous publications, and their general kinetic characteristics are summarized. The kinetic studies are also extended to include the dealkylations of (methylaquo)?3,5,6-trimethylbenzimidazolylcobamide and protonated base-off ethylcobalamin by IrCl (1.0M Cl^?) and by Fe(III) ions at 0.1M Cl^?, and the demethylation of (methylaquo)?3,5,6-trimethylbenzimidazolylcobamide by AuCl (1.0M Cl^?). This extension is in an effort to substantiate the general mechanism which has been previously proposed for these oxidative dealkylations. The general kinetic characteristics are described in terms of a preassociation of the reactants, followed by a rate-determining electron-transfer process to yield the R-B radical, which then undergoes further reactions to produce the products observed. The overall reactions are discussed within the framework of chlorine-bridging inner sphere electron-transfer reactions.     

Über hexagonale Perowskite mit Kationenfehlstellen. XXXI. Die Systeme BaO?Re2O7?MO5 mit MV = Nb,Ta

On Hexagonal Perovskites with Cationic Vacancies. XXXI. Systems BaO? Re₂O₇? M O₅ with M^V = Nb, Ta In the systems BaO? Re₂O₇? MO₅ three quaternary oxides are formed, which belong to the perovskite stacking polytypes with cationic vacancies: Ba₈Re_7/2M□₃O₂₄ (M^V = Nb, Ta; rhombohedral 24 L type; sequence (hhhhchhc)₃; space group R3 m), Ba₄Re_9/8Ta_13/8□_5/4O₁₂ (rhombohedral 12 L type; sequence (hhcc)₃; space group R3 m) and the phases Ba₅BaRe_3/2?xM □O_15?x□_x (M^V = Nb, Ta; variants of a hexagonal 5 L type).     

Darstellung, 19F-NMR-spektroskopischer Nachweis und Untersuchung zur Bildung der metallgemischten Clusteranionen [(Mo6−nWnCl)F]2−, n = 0−6

Preparation, ¹⁹F NMR Spectroscopic Evidence and Study of the Formation of Metal-Mixed Cluster Anions [(Mo_6?nW_nCl )F ]^2?, n = 0?6 The complete system of metal-mixed octahedral cluster ions [(Mo_6?nW_nCl)F]^2?, n = 0?6, is prepared by tempering Mo powder with WCl₆ at 600°C. A mixture containing inclusively the geometric isomers (n = 2, 3, 4) all ten possible species is transferred into the tetra-n-butylammonium salts (TBA)₂[(Mo_6?nW_nCl)F]. In the ¹⁹F nmr spectrum the 24 expected signals are observed, assigned on the basis of their chemical shifts, multiplicities and intensities, and confirmed by a 2D-¹⁹F-¹⁹F COSY spectrum. From the integrated intensities the distribution of the different components is derived revealing a non-statistical formation, in that isomers with Mo…?Mo or W…?W atoms in trans-positions in comparision to those with mixed Mo…?W axes are favoured, and that especially the homoleptic compounds Mo₆ and W₆ are present to an over-average extent. Evaluation of ¹⁹F chemical shifts reveals that F bound to W which is in antipodal position to Mo resonates at higher field compared to F bound to W in a W…?W arrangement, caused by an increased shielding, which is synonymous to a positive antipodal-effect by Mo. Vice versa F bound to Mo with an antipodal W resonates at lower field compared with F bound to Mo in an Mo…?Mo arrangement caused by an increased deshielding and synonymous a negative antipodal-effect by W. The chemical shifts, resulting from antipodal-effects, are different for the compounds within the [(Mo_6?nW_nCl)F]^2? - system. The difference of the antipodal effect of successive substitution products results in characteristic values designated as antipodal shift constants, depending on the kind of substituents, which is valid for other cluster systems, too.     

Über Perowskite ABBWVIO6

On Perovskites A B B W^VIO₆ Compounds of type ABBW^VIO₆ can be obtained with A^II ? Ba; B^I ? Li, Na and B^III ? La, Nd, Sm, Gd, Y, In, Sc just as with A^II ? Sr, B^I ? Li and B^III ? La, Nd, Sm, Gd, Y, In (all cubic ordered perovskites). For the cubic perovskites Sr₂Na_0,5La_0,5WO₆ and Sr₂Na_0,5Nd_0,5WO₆ additional superlattice reflections are observed (a ∽ 16.4 Å). The compounds Sr₂Na_0,5BWO₆ crystallize with B^III ? Sm, Gd in a monoclinic and with B^III ? Y, In in a rhombic distorted perovskite lattice. For the perovskites with A = Sr — dependent on ionic radii of the B ions — two different lattice types are present.     

Das Indiumsesquichlorid,In2Cl3: ein pseudobinäres,gemischtvalentes Indium(I)-hexachloroindat(III)

Indium Sesquichloride, In₂Cl₃: a Pseudobinary, Mixed-valence Indium(I) Hexachloroindate(III) Colorless In₂Cl₃, obtained by reduction of InCl₃ with metallic In, according to In[In^IIICl₆] a pseudobinary, mixed-valence indium(I) hexachloroindate(III), crystallizes orthorhombic (Pnma, Z = 32) with a = 1261.4(3), b = 2523.8(5), c = 1456.2(2) pm (Guinier-Simon data), V_m(In₂Cl₃) = 87.3 cm³ × mol^?1. In^III occupies octahedral holes separated from each other (d?(In^III? Cl) = 251 pm). Coordination numbers of 7 to 11 are observed for In^I (d?(In^I? Cl) = 329–359 pm). In₂Cl₃ is isotypic with α-Tl₂Cl₃.     

Control of Oxidation States of Transition Elements (Cr,Mn) in Nitridometalates and the Solid Solution Series Li6(Ca1‐xSrx)2[Mn2N6]

The formation of ternary nitridometalates from the elements in the case of the systems Li—Cr, V, Mn—N leads to compounds which contain the transition metals in the highest (V^V, Cr^VI) or a comparably high (Mn^V) oxidation state. In the corresponding calcium and strontium systems, the transition metals show a lower oxidation state (V^III, Cr^III, Mn^III). Transition metals with intermediate oxidation states (Cr^V, Mn^IV) are present in the quaternary (mixed cation) compounds Li₄Sr₂[CrN₆], Li₆Ca₂[MnN₆], and Li₆Sr₂[MnN₆] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3), as well as in the solid solution series Li₆(Ca_1—xSr_x)₂[MnN₆].     

Berechnungen zur Kinetik der Bildung von Chloro-Bromo-Iodo-Osmaten(IV)

Kinetic Calculations for the Formation of Chloro-Bromo-Iodo-Osmates(IV) Rate constants of formation and ligand exchange reactions of mixed hexahaloosmates(IV) of the type [OsCl_xBr_yI_6?x?y]^2?, x + y = 2?5, are computable taking into account the relative cis- (f = 1, f = 1.75, f ≈? 6) and trans-effects (f = 1, f = 6, f ≈? 10³) of the ligands as well as statistic factors. Using this kinetic data concentration-time diagrams are calculated for reactions including several parallel and consecutive steps. They agree well with the experimentally determined distribution of products in the reaction mixtures. For the preparation of particular mixed ligand complexes the best way of synthesis and maximum yield can be precalculated.