Über Rubidiumozonid. Reindarstellung und Kristallstruktur

On Rubidium Ozonide. Synthesis and Crystal Structure An improved route for the synthesis of rubidium ozonide is reported. Via repeated ozonization of the hyperoxide at room temperature and extraction with liquid ammonia, pure rubidium ozonide is for the first time available in preparative amounts (1–5 g) and moreover as single crystals. The crystal structure determination (P2₁/c; a = 645.2(3), b = 602.2(3), c = 876.3(3) pm, ß 122.34(2)°; ?20°C; MoKα 2640 diffractometer data; R_w = 2.6%) proves the expected constitution of the anion O₃^?, which within the range of error belongs to the point group C_2v with d (O? O) = 133.6(9) pm and a bonding angle of 113.7(7)°. With respect to the packing of cations and anions there is a close relationship to the CsCl-type of structure.     

Über die strukturellen Probleme des Di-cyclopentadienyl-titans

On the basis of spectral and chemical evidence it is shown that bis(cyclopentadienyl)titanium is not a sandwich-π-type compound. The most probable structure in solution is that of a dimer containing metal-metal bond and π-and σ-bonded cyclopentadienyl rings.     

Über die Pentahydrogen-12-vanadophosphate des Lithiums,Magnesiums und Calciums

On the Pentahydrogen-12-vanadophosphates of Lithium, Magnesium, and Calcium Concentrated solutions of lithium, magnesium, and calcium vanadates react with phosphoric acid and nitric yielding the red pentahydrogen-12-vanadophosphates. The number of hydrogen ions of the 12-vanadophosphate anion was determined by potentiometric titration with NaOH at various temperatures.     

Überblick über die Phosphide des Strontiums

The method of the reaction in a stainless steel cube which was used for the first time in the preparation of barium phosphides is also applicable to phosphide-producing mixtures of strontium and phosphorus. In connection with high temperature experiments it served to obtain a survey of the binary system strontium—phosphorus. This binary system is largely analogous to the binary system barium—phosphorus. The compounds found were: “Sr₂P”, Sr₃P₂, Sr₄P₃? Sr_1,1P, SrP, Sr₄P₅ and SrP². The strontium-rich phosphides have melting or decomposing temperatures which are higher than those of the analogous barium phosphides. The powders of Sr₃P₂, Sr₄P₃ and SrP are brown to blackviolet. Sr₃P₂ cristallizes isostructurally with Ba₃P₂. Some properties indicate that the bonding is more ionic than in Ba₃P₂. The structural relationship of the alkaline earth pnietides with the lanthanide chalogenides is discussed. Sr₃P₂ and Ba₃P₂ complete the inverse isostructures of these compounds.     

Über die absolute Konfiguration der Cantharsäure und des Palasonins

The absolute configurations of (+)-cantharic acid, a chiral derivative of the achiral insect defensive substance cantharidin ( 1 ), and of palasonin, a lower homologue of 1 occurring in the plant Butea frondosa, were shown to be represented by formulas 2 and 3 , respectively (scheme 1). These results were obtained by application of the Horeau method (table 1) on the (+)-cantharic acid derivatives (+)- 5 , (?)- 7 , and (?) 11 (scheme 2), and the palasonin derivatives (+)- 29 and (+)- 30 (scheme 4), as well as by comparison of the chiroptical properties (tables 2 and 3) of a number of derivatives, prepared from either cantharic acid or palasonin. – Attempts to incorporate various radioactively labelled precursors into palasonin ( 3 ), using young and adult plants, have been so far unsuccessful.     

Über Tetraiodomercurate des Calciums und Strontiums

On Tetraiodomercurates of Calcium and Strontium Tetraiodomercurates MHgI₄ · 8 H₂O (M ? Ca, Sr) as yellow crystals are obtainable by crystallization from aqueous solutions. Both compounds are not isotype in spite of consisting isolated [M(OH₂)₈] cations and tetrahedral [HgI₄] anions which are cubic closed packed. In the structure of the tetragonal CaHgI₄ · 8 H₂O (a = 13.972(3) Å; c = 18.155(4) Å; Z = 8; P4₂/mbc) are dodecahedral [Ca(OH₂)₈] cations, but antiprismatic [Sr(OH₂)₈] groups in the orthorhombic compound SrHgI₄ · 8 H₂O (a = 9.616(3) Å; b = 10.610(3) Å; c = 17.731(4) Å; Z = 4; Pcmn). The relations between both structure concerning a tetragonal “Aristotype” are discussed.     

Über s-Triazinium-Salze und Additionsverbindungen des s-Triazins

Several unknown salts of s-triazine were prepared by different methods and the IR spectra of most of these salts were assigned. When s-triazine was reacted with HCl or HBr, mixtures were obtained which consisted of s-triazinium-monohalogenides and products with higher contents of hydrohalogenides. When s-triazine was reacted with HJ, a product C₃H₃N₃ · 3 HJ was obtained. The IR spectra of this compound and of the corresponding compound with DJ were taken to interprete the structure. Addition compounds of s-triazine with several ansolvo-acids were produced in which one or two ansolvo-acid molecules were bound to one molecule of s-triazine. The IR spectra of some of said addition compounds were assigned. Moreover, an adduct of bromine and s-triazine, C₃H₃N₃ · Br₂, was prepared.     

Über Silicid- und Germanidchalkogenide des Thoriums

On Thorium Silicide and Germanide Chalcogenides The compounds ThSiS, ThSiSe, ThSiTe, ThGeS, ThGeSe, and ThGeTe were synthetized from the elements at temperatures ranging from 800 to 1050°C. For structural X-ray investigation single crystals of the compound ThGeS were grown. ThGeS is tetragonal, space group I4/mmm with a = 3.9411(7), c = 17.1395(40) Å, and Z = 4. In order to refine the structure parameters intensity measurements were carried out by means of a four-circle single crystal diffractometer. By indexing the Debye-Scherrer diagrams the remaining ternary thorium chalcogenides were proved to be isostructural with ThGeS. This structure type is identical with the anti-Ti₂Bi-type structure and closely related to the PbFCl structure in the sense of a transposition structure. The interatomic distances, the relations to comparable structures and possible reasons for the formation of the anti-Ti₂Bi-type structure by ternary chalcogenides of the actinides are discussed.     

Über die Phosphidierung des Nickels durch Phosphortrichlorid

On the Phosphidation of Nickel by Phosphorus Trichloride The phosphidation of nickel sheets by phosphorus trichloride vapor of 30 and 50 Torr has been studied kinetically by gravimetric means in the temperature range of 400–650°C in hydrogen atmosphere. The phosphidation proceeded generally according to the parabolic rate law. The parabolic rate constant increased with an increase of temperature, and its temperature dependence yielded the activation energies of about 33 and 47 kcal/mole for 400–550 and 550–650°C, respectively. X-ray and electron microprobe analyses showed that surfaces of the specimens phosphidized are made up of mixtures of Ni₂P and Ni₆P₅, and that at the phosphide/metal interface the compound Ni₂P is formed. The experiments using argon as carrier gas resulted in the formation of both the phosphides and the chlorides, and this fact could be explained in terms of thermodynamics.     

Über Polyphosphide des Lanthans und Cers

The systems LaP/P and CeP/P were investigated. Polyphosphide phases with the compositions LaP_1.6–2.5 (A), LaP_3.5–5.3(B), LaP_5.8–9.0(C) and LaP_6.5–8.9(D), respectively, as well as CeP_1.7–2.4 (A′), CeP_3.5–6.5(B) CeP_6.5–9.0(C) and were found. The phases B and C of lanthanum and cerium are isotypic, but not the phases A and A′. The phases C and D of lanthanum are different modifications with approximately equal homogenity ranges.     

Über die Funktion des Kations und der Solvatmolekeln in kristallisierten Monocyclopentadienyl–Anionen-Komplexen des Chroms

On the function of the cation and solvent molecules in crystallized chromium monocyclopentadienyl complexes The two structure types for monocyclopentadienyl-chromium complexes, proposed by Fischer and by Otto, are equivalent ones, regarding the bonding character. The cation, existing only for structure type I, contributes to the charge neutrality, behaves, in combination with only one field ligand, as an ?electron donor”?, and allows for the characteristic ligand field symmetry C_s for these complexes. The solvate molecules exert a stabilizing effect both via attenuating the polarizing action of the cations and via their arrangement in the crystal lattice.     

Über die Oxydation des O-Methylbulbocapnins mit Jod

The oxidation product obtained by treatment of bulbocapnine methyl ether ( 2a ) with iodine in ethanol/water is not the tetradehydroaporphinium salt 4 as assigned by Gadamer & Kuntze, but a dimer of structure 3 . Reduction of 3 with zinc in dilute sulfuric acid gives rac-bulbocapnine methyl ether, whereas reduction with complex hydrides affords the diastereomeric dimers 7a and 7b .     

Über die Eigenschaften des Xp-Teils von AnBXp-Kernresonanzspektren

The subspectral breakdown of the X-part in A_nBX_p-spectra is derived and the general properties of the subspectra are discussed. The nature of the asymmetry of X_p-spectra for n > 1 is explained and conditions for its disappearance are given. The degeneration of the X_p-part into deceptively simple spectra is described and degeneration conditions are derived. The determination of relative signs of coupling constants is discussed.     

Über die Cyanamidolyse von Natriumtri- und -tetrametaphosphat

Cyanamidolysis Reactions of Sodium Tri- and Tetrametaphosphate Reactions of Na₂NCN with sodium tri- and tetrametaphosphate are leading to the formation of Na₃PO₃N₂C, NaPO₂(N₂(C)₂), Na₃PO₄, and Na₄P₂O₇, respectively. In alkaline aqueous solutions hydrolysis and cyanamidolysis reactions occur parallel. The course of the different reactions is discussed.     

Über Fluoride des einwertigen und des zweiwertigen Quecksilbers

On Fluorides of Univalent and Divalent Mercury For the first time Rb₂HgF₄ and Cs₂HgF₄, both colourless, have been obtained. From single crystal investigations they crystallize tetragonal in the K₂NiF₄-type of structure, space group I4/mrnm-D_4h¹⁷ (No. 139) with a = 455.6 pm, c = 1375.7 pm, Z = 2 for Rb₂HgF₄ and a = 462.5 pm, c = 1451.8 pm, Z = 2 for Cs₂HgF₄. The determination of the crystal structure of Hg₂F₂ confirmed the unit cell [1] with a = 367.00(4) pm, c = 1090.1(2) pm, Z = 2 space group I4/mrnm-D_4h¹⁷ (No. 139).