Über hexagonale Perowskite mit Kationenfehlstellen. XIV Die rhomboedrischen 12 L-Stapelvarianten Ba2La2BII(W□O12)

On Hexagonal Perovskites with Cationic Vacancies. XIV. The Rhombohedral 12 L-Stacking Polytypes Ba₂La₂B^II(W □O₁₂) Rhombohedral 12 L-stacking polytypes with cationic vacancies of type Ba₂La₂B^II-(W□O₁₂) are reported for B^II = Mg, Zn (white), Ni(light brown) and Co(brown). They crystallize in the space group R3 m, sequences (3 )(1) ? (hhcc)₃. For B^II = Cu, as a consequence of the Jahn Teller effect, a triclinic distorted lattice is observed.     

Die Kristallstruktur von Perowskiten ANiIIMVIO6. II. Das Sr2NiWO6

The Crystal Structure of Perovskites A Ni^IIM^VIO₆. II. Sr₂NiWO₆ The results of an X-ray single crystal study of the perovskite Sr[Ni^IIW^VI]⁽⁶⁾O₆, ordered in the octahedral sites, are given. While Sr[Ni^IITe^VI]⁽⁶⁾O₆ crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[Ni^IIW^VI]⁽⁶⁾O₆ is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO₆ polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment.     

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.     

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).     

Low Valence States of Metal Chelates. V. Tris(1,10-phenanthroline)cobalt(II) and bis(2,9-dimethyl-1,10-phenanthroline)cobalt(II) perchlorates

D. C. polarography and cyclic voltammetry were used for investigating the reduction processes of the tris(1,10-phenanthroline)cobalt(II) and bis(2,9-dimethyl-1, 10-phenanthroline)-cobalt(II) perchlorates in 0.1 M solutions of tetraethylammonium perchlorate in acetonitrile. The first complex gave a four-step reduction wave; the first two steps were found to be diffusion controlled and reversible reductions from Co(phen)⁺ to Co(phen)₃⁺ to Co(phen) to Co(phen;) occured. The second complex gave a six-step reduction wave; the first three steps were found to be diffusion controlled and were to be considered as successive reversible reductions from Co(2, 9dm-phen)⁺ to Co(2, 9dmphen), from Co(2, 9dmphen) to Co(2, 9dmphen)₂ and from Co(2, 9dmphen)₂ to Co(2, 9dmphen).     

Herstellung von Fluorophosphaten,Difluorophosphaten, Fluorophsophonaten und Fluorophosphiten in fluoridhaltigen Harnstoffschmelzen

Preparation of Fluorophosphates, Difluorophosphates, Fluorophosphonates, and Fluorophosphites in Fluoride-containing Urea Melts Phosphoric acid, phosphonic acid, and organylphosphonic acid react on heating in fluoride-containing urea melts in high yields to fluorophosphates, MPHO₂F, organylfluorophosphonates, M¹RPO₂F, organylpolyfluorophosphonates, MR¹CX(PO₂F)₂, MN(CH₂PO₂F)₃, and phosphonoorganylfluorophosphonates, MR¹CX(PO₃)PO₂F (M¹ = K, NH₄; R = organic substituent; R¹ = H, organic substituent; X = OH, NH₂, NR₂). The reaction mechanism of the formation of fluorophosphate ions in fluoride containing urea melts is discussed.     

Magnesium chloride supported high mileage catalysts for olefin polymerization. XII. Polymerization of ethylene

Polymerizations of ethylene by the MgCl₂/ethylbenzoate/p-cresol/AlEt₃ TiCl₄-AlEt₃/methyl-p-toluate (CW-catalyst) have been studied. The initially formed active site concentration, [Ti] has a maximum value of 50% of total titanium at 50°C and lower values at other temperatures. The Ti decays rapidly to Ti sites with conc. ca. 10 mol %/mol Ti. The rate constants for four chain transfer processes have been obtained at 50°C: for transfer with AlEt₃, k = 2.1 × 10^?4 s^?1 and k = 4.8 × 10^?4 s^?1; for transfer with monomer, k = 3.6 × 10^?3 (M s)^?1 and K = 8.3 × 10^?3 (M s)^?1; for β-hydride transfer, k = 7.2 × 10^?4 s^?1 and k = 4.9 × 10^?4 s^?1; and transfer with hydrogen, k = 4.0 × 10^?3 torr^1/2 s^? and k = 5.1 × 10^?3 torr^1/2 s^?1. The rate constants for the termination assisted by hydrogen is k = 1.7 (M^1/2 torr^1/2 S)^?1. If monomer is assisting termination as was observed for propylene polymerization, then k = 7.8 (M^3/2 s)^?1. Values of all the rate constants can be higher or lower at other temperatures. Detailed comparisons were made with the results of propylene polymerizations. There are more than four times as many Ti active sites for ethylene polymerization than there are for stereospecific polymerization of propylene; the difference is more than a factor of two for the Ti sites. Certain rate constants are nearly the same for both monomers while others are markedly different. Some of the differences can be explained by stereoelectronic effects.     

Untersuchungen an elektronenleitenden Oxidsystemen. XXI. Stabile spinelle ZnzNiMn2−zO4 und Vergleich mit Spinellen MgzNiMn2−zO4

Investigations on Electronically Conducting Oxide Systems. XXI [1] Stable Spinels Zn_zNiMn_2?zO₄ and Comparison with Spinels Mg_zNiMn_2?zO₄ Stable spinels are obtained in the result of substitution of Zn^II for manganese in the series Zn Ni^IIMnMnO₄ (O ? z ≤1). Different from spinels Mg Ni^IIMnMnO₄ (O ? z ?1)they don't be submitted to decomposition in air during slow cooling at medium temperatures. ZnNiMnO₄ (z=1) could not be prepared in a mono-phase state which is indicated by the composition of ZnNiMnO_3.96 deduced from analysis by oxidimetric titration. The comparably small variation of the specific electrical conductivity and of the activation energy observed in the range O ? z ? 2/3 for Zn_zNiMn_2?z is discussed in relation to larger alterations in the series Mg_zNiMn_2?zO₄. Structural interpretation is proposed based on the comparison of the molar volume of spinels M Mn₂O₄ (M: Mn, Fe, Co, Ni, Cu, Zn, Mg).     

Über hexagonale Perowskite mit Kationenfehlstellen. XXVI. Ba12Ba2 2/3M 1/3□2O33□3 (MV = Nb,Ta) – die ersten Stapelvarianten eines rhomboedrischen 36 L-Typs

On Hexagonal Perovskites with Cationic Vacancies. XXVI. Ba₁₂Ba_{2 2/3}M _1/3□₂O₃₃□₃ (M^V = Nb, Ta) – the First Stacking Polytypes of a Rhombohedral 36 L-Type In the systems BaO? MO₅(M^V = Nb, Ta) for a Ba:M^V ratio of 2:1 polymorphism is observed. Here the low temperature modifications are described. They crystallize in a rhombohedral 36 L structure with three formula units Ba₁₂Ba_{2 2/3}M _1/3□₂O₃₃□₃ for the trigonal setting (M^V = Nb: a = 5.92₂ Å; c = 93.₂₅ Å; Ta: a = 5,92₂ Å; s = 93.4 Å).     

Subgroup 4 (Ti,Zr, Hf) derivatives of Cobalt Carbonyls

Bimetallic and trimetallic compounds containing unsupported bonds of subgroup 4 metals (M = Ti, Zr, Hf) and Co were prepared by hydride elimination (A) from RM derivatives (R¹ = PhCH₂; RN; R² = Me, Et)) and by salt elimination (B) from RMX (X = Cl, Br; R.¹ = PhCH₂, RN and R³O; R³= i-Pr, n-Bu)) by reaction with HCo(CO)₄ and Na[Co(CO)₄], respectively. Compounds RMCo(CO)₄ with R¹ = PhCH₂, RM[Co(CO)₄]₂ R.¹ = PhCH₂, were prepared both by methods A and B, while (R³O)₄-n Ti[Co(Co)₄]n (n = 1, 2) compounds were obtained by reaction B. Several tertiary phosphine and phosphite derivatives of the former two types were obtained by substitution of a carbonyl group by PR ligand or by A type reaction of HCo(CO)³(PR with RM compounds.     

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.     

Zur Kenntnis von NiPtF6 und CdPtF6

Anotation to Compounds MPtF₆ (M = Ni, Cd) Yellow single crystals of M¹¹PtF₆ (M¹¹ = Ni, Cd) have been obtained for the first time and investigated by X-ray methods. The powder data of the compounds are confirmed. Both samples are isostructural to LiSbF₆, space group R3 -C (Nr. 148) with a = 500.5(3) pm, c = 1375.6(7) pm for NiPtF₆ and a = 511.56(9) pm, c = 1460.3(4) pm for CdPtF₆, Z = 3.     

The kinetics of the interaction of peroxy radicals. I. The Tertiary Peroxy Radicals

Existing data on the self-reactions of tertiary peroxy radicals RO₂ has been reanalyzed and corrected to deduce Arrhenius parameters for both termination and nontermination paths. For R = t-Butyl, these are logk_t(M^?1sec^?1) = 7.1 - (7.0/θ) and logk_nt(M^?1sec^?1) = 9.4 - (9.0/θ), respectively, different from those recommended by other authors. The higher magnitudes observed for termination processes of tertiary peroxy radicals like those of cumyl and 1,1-diphenylethyl have been discussed in terms of a much greater cage recombination of cumyloxy radicals as contrasted with t-butoxy radicals. It is shown that for benzyl peroxy radicals, the R—O bond dissociation energy is sufficiently low (18–20 kcal) that reversible dissociation into R^˙ + O₂ opens a competing second-order path to fast recombination R^˙ + RO → ROOR. This path is probably not important for cumyl peroxy radicals under usual experimental conditions but can become important for 1,1-diphenyl ethyl peroxy radicals at (O₂) < 10^?3M. At very low RO concentrations (<10^?5M), in the absence of added O₂, an apparent first-order disappearance of RO can occur reflecting the rate determining breaking of the cumyl—O bond followed by the second step above. The thermochemistry of RO is used to show that the reaction of R₂O₄ → 2RO + O₂ must be concerted and cannot proceed via RO which is too unstable and cannot form even from RO^˙ + O₂.     

Beiträge zur Chemie des Phosphors. 162. MP19 (MI  Li,Na, K), die ersten Salze mit Nonadecaphosphid(3-)-Ionen

Contributions to the Chemistry of Phosphorus. 162. M P₁₉ (M^I ? Li, Na, K), the First Salts with Nonadecaphosphide (3-) Ions The nonadecaphosphides Li₃P₁₉, Na₃P₁₉, and K₃P₁₉ are formed besides other polyphosphides by the nucleophilic cleavage of white phosphorus with lithium dihydrogenphosphide or sodium and potassium, respectively. Li₃P₁₉ also results from the reaction of Li₃P₇ with white phosphorus or iodine or 1, 2-dibromoethane, as well as from the degradation of Li₂P₁₆ with lithium dihydrogenphosphide. According to 2D-³¹P-NMR-spectroscopic investigations the P₁₉^3? ion is a conjuncto-phosphane made up of a central P₅^? structural element and two Pg(3)^? unit groups analogous to deltacyclane. The nonadecaphosphides M₃^IP₁₉ are intermediates in the formation of hexadecaphosphides MP₁₆ from heptaphosphides MP₇.     

Interactions Magnetiques dans quelques Ferrites Oxyfluores a Structure Spinelle de Formule ZnxMFe2−xO4–xFx (M ? Fe,Co, Ni)

Magnetic interactions in some oxyfluoroferrites of spinel structure with the formula Zn_xMe_2?xO_4?xFx (M = Fe, Co, Ni) Whereas the ferromagnetic spin arrangement of the B-cations is not modified by the Zn²⁺?Fe³⁺ substitution in the ZnFe[Fe₂₊Fe³⁺]O_4?xF_x (0 ≤ x ≤ 0,50) spinel, this same substitution leads to a spin canting in the ZnFe[Co₂₊Fe³⁺]O_4?xF_x and ZnFe[Ni₂₊Fe³⁺]O_4?xF_x (0 ≤ x ≤ 0,80) simples. The difference in the magnetic behaviors with regard to the AB and BB interactions can be explained on the basis of the magnetic exchange theory.     

Über α-Dioximin-Komplexe der übergangsmetalle. XXIII) Kobalt(III)-nyoximin-Komplexe mit aromatischen Aminen

30 new binary salts of the heretofore unknown type [Co(NioxH)₂(Amin)₂]X were obtained by air oxidation of an alcoholic aqueous solution of Co^II acetate in the presence of 1,2-cyclohexanedione dioxime (nioxime) and an aromatic amine (aniline, o-and p-ethylaniline and m-xylidine). From the brown solutions of the resulting; Co(NioxH)₂(amine)₂; acetates the desired salts were separated by means of double decomposition reactions using X ? Br^?, NO, ClO, HSO, Pikart, [Cr(NH₃)₂(NCS)₄]^?, 1/3[Cr(NCS)₆]^3? and [Co(NioxH)₂(NO₂)₂]^?; NioxH ? C₆H₉N₂O₂. From spectroscopical investigations in the UV and IR regions some structural problems are resolved and discussed.     

Über geordnete Perowskite mit Kationenfehlstellen. X. Verbindungen vom Typ ABB□1/4MVIO6 ≙ ABIIB□MO24 mit AII,BII = Ba,Sr, Ca und MVI = U,W

On Ordered Perovskites with Cationic Vacancies. X. Compounds of Type A B B □_1/4M^VIO₆ ? A B^IIB □M O₂₄ with A^II, B^II = Ba, Sr, Ca and M^VI = U, W Perovskites of type Ba₈B^IIB₂^III□UO₂₄ show polymorphic phase transformations of order disorder type. An 1:1 ordered orthorhombic HT form is transformed into a higher ordered LT modification with a fourfold cell content (four formula units Ba₈B^IIB□U₄O₂₄), compared to cubic 1:1 ordered perovskites A₂BMO₆. In the series Ba₈BaB□W₄O₂₄ and Sr₈SrB□W₄O₂₄ different ordering phenomena are observed. In comparison with 1:1 ordered cubic perovskites A₂BMO₆, the cell contains eight formula units AB^IIB□W₄O₂₄. The higher ordered cells with U^VI and W^VI are face centered, which has its origin in an ordering of cationic vacancies.     

Chemie und Strukturchemie von Phosphiden und Polyphosphiden. 53. Darstellung,Eigenschaften und Schwingungsspektren der Käfiganionen P113− und As113−

Chemistry and Structural Chemistry of Phosphides and Polyphosphides. 53. Preparation, Properties, and Vibrational Spectra of the Cage Anions P₁₁^3? and As₁₁^3? The Zintl-phases M₃X₁₁ (M = Na, K, Rb, Cs; X = P, As) are prepared from the elements or from M₃X₇ and X. The compounds undergo a first-order phase transition from the crystalline to the plastically crystalline state. Unit cell and space group of both modifications and the transition temperature T_c are determined. The vibrational spectra of the crystalline compounds and the Raman spectrum of the P₁₁^3? anion in en-solution as well are measured. The assignment of the frequencies is given, based on the 32-D₃ symmetry of the X₁₁^3? cage anion. Normal coordinate analysis is carried out in terms of Cartesian coordinates to avoid the problem of redundancies in using internal coordinates. The force constants [mdyn Å^?1] obtained for the characteristic bonds r, s, and t are: f = 1.34, f = 1.20, f = 1.08; f = 1.1, f = 0.91. Normal vibrations and the potential energy distribution (PED) are discussed.     

Übergangsmetallchalkogenverbindungen. Monothiodiselenomolybdate(VI) und -wolframate(VI) Darstellung,Elektronenspektrum und röntgenographische Untersuchung

The preparation of MMoOSSe₂ and MWOSSe₂ (M^I = Cs, Tl) is reported. The measured IR and electronic absorption spectra are discussed. It was found by X-ray studies that both cesium salts are crystallising in the space group D—Pnma with Z = 4 (For dimensions of the unit cell and density see Inhaltsübersicht).     

Zur Struktur der LiMIIMIIIF6-Verbindungen. Neue Verbindungen mit MIII=In und Ti

On the Structure of LiM^IIM^IIIF₆ Compounds. New Compounds with M^III=IN and Ti LiMn^IIInF₆ compounds with M^II = Mg, Mn, Co, Ni, Zn, Cd and Ca crystallize in the Na₂SiF₆ structure. The Ti(III) compound LiMgTiF₆ has trirutile structure, LiMnTiF₆ has Na₂SiF₆ and trirutile structure (H.-T. modification), LiCaTiF₆ and LiCdTiF₆ have Li₂ZrF₆ superstructure. With M^II = Co, Ni and Zn solid solutions trirutile — MF₂(rutile) could be only prepared. The lattice constants of all compounds are reported. For LiMnVF₆ and LiFeGaF₆ too dimorphism Na₂SiF₆ trirutile was observed. In the system LiNiCrF₆ (trirutile) — LiMnCrF₆ (Na₂SiF₆ structure) phase limits of both structures are determined in dependence on the ratio of ionic radii r/r. Magnetic data of the In compounds with M^II = Co and Ni and of the Ti(III) compounds with M^II = Mg, Zn, Mn, just as of α- and β-LiMnVF₆ are also given. The three structures only exist if r reaches from 0.6 to 1.2 Å and r from 0.5 to 0.8 Å. The stability-fields are determined by the ratio of ionic radii r/r_Li, r/r_Li and r/r: trirutile 0.9–1.2, Na₂SiF₆ type 1.2–～1.4 and Li₂ZrF₆ superstructure >1.4. The dependence of rate of ionic radii is explained by the different sharing of MF₆ octahedra.