Über den α-NaFeO2-Typ: Zur Kenntnis von NaCrO2 und KCrO2

on the α-NaFeO₂ type: about NaCrO₂ and KCrO₂ Single crystals of NaCrO₂ (“chromic-green”) and KCrO₂ (deep dark green), always hexagonal plates, were prepared for the first time. Homogeneous mixtures of Na₂O resp. K₂O (Na:Cr = 1.1 : 1 resp. K : Cr = 1.1 : 1) and Cr₂O₃ were heated in closed Ni-tubes at 1000°C (1100°C). Heating up and cooling down slowly. Corresponding powder samples were obtained at 500°C (700°C). Four-circle-diffractometer dates were used to derive the structure determining parameter z_o. Madelung part of lattice energy, MAPLE, was calculated.     

Zwei Vertreter des α-LiFeO2 Typs: LilnO2 und α-LiYbO2 [1, 2]

Two Representatives of the α-LiFeO₂ Type: LiInO₂ and α-LiYbO₂ Single crystals of LiInO₂ (well ground mixtures of ‘In₂O’: KO₂: Li₂O = 1:1.8:1, Ag-tube, 22d, 520°C); and α-LiYbO₂ (Yb₂O₃:Li₂O = 1:1.1, Ni-tube, 30d, 1150°C) were prepared for the first time from mixtures of the binary oxides. The determination of the structure confirmed the α-LiFeO₂ type. Both oxides crystallize in the space group I 4₁/amd (Z = 4); LiInO₂: a = 431.2(1) pm c = 934.2(2) pm; c/a = 2.167; 123 I_o(hkl), R = 3.6%, R_w = 2.9%. α-LiYbO₂:a = 438.7(1) pm c = 1006.7(2) pm; c/a = 2.295, 130 I_o(hkl), R = 4.4%, R_w = 3.6%. The Madelung part of lattice energy, MAPLE and characteristics of this kind of structure are discussed.     

Ein Beitrag über BaLaGaO4 und BaNdGaO4: Verwandte Verbindungen zum β-K2SO4-Typ sowie über SrLaGaO4 mit K2NiF4-Struktur

A Contribution about BaLaGaO₄ and BaNdGaO₄: β-K₂SO₄ Type Related Compounds and about SrLaGaO₄ with K₂NiF₄ Structure (I) BaLaGaO₄, (II) BaNdGaO₄, and (III) SrLaGaO₄ were prepared by solid state reactions and investigated by X-ray single crystal technique. (I) and (II) crystallize with a β-K₂SO₄ type related structure. Ba²⁺ and La³⁺/Nd³⁺ occupy two point positions in an ordered manner, Ga³⁺ shows a tetragonal coordination. SrLaGaO₄ has K₂NiF₄ structure. Sr²⁺ and La³⁺ are distributed statistically, Ga³⁺ is surrounded by O^2?-octahedra which are stretched along [001].     

Notiz über Li2PdO2

Note on Li₂PdO₂ For the first time we prepared ruby-red single crystals of Li₂PdO₂ by reaction with the wall 3 Na₂O + Li₂O₂ + ?Tb₄O₇”?(+ Pd) = 3 Na₂TbO₃ + Li₂PdO₂ + ?TbO₂”?, Pd-tube, 1100°C, 7 d. Single crystal data confirm the Li₂CuO₂-type of structure [a = 375.34(5), b = 298.18(4), c = 931.58(10) pm; spacegroup Immm; d_x = 4.85 g · cm^?3; 144 I₀(hkl); R = 3.54%, Rw = 3.19%; MoKα ; four-circle diffractometer Philips PW 1100] and reveal clearly different parameters compared with those deduced by powder data. The Madelung Part of Lattice Energy, MAPLE, corresponds now to the sum of the MAPLE values of the binary oxides.     

Neues über Oxouranate: Über α-Li6UO6. Mit einer Bemerkung über β-Li6UO6

New Investigations about Oxo Uranates: On α-Li₆UO₆. With a Remark about β-Li₆UO₆ The crystal structure of transparent, bright yellow single crystals of α-Li₆UO₆ has been determined. [a = 838.07(5), c = 738.34(7) pm; d_pyk = 4.02, d_x = 4.17 g · cm^?3; space group R3 ; Z = 3; R = 3.17%, R_w = 3.06%; 408 symmetry independent I₀(hkl); AgKα fourcircle diffractometer Philips PW 1100]. The structure is dominated by a threedimensional framwork of “hollow spaces”, built up by 12 O^2? (and 12 Li⁺). The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.     

Notiz über die Reaktion zwischen Phosphortrichlorid und Schwefelwasserstoff

Notice on the Reaction between Phosphorus Trichloride and Hydrogen Sulfide The reaction between phosphorus trichloride and hydrogen sulfide in the presence of a base yields P₄S₃ and [PS₂Cl₂]^? besides other products. A reaction scheme is proposed.     

Notiz über Ellagitannine und Flavonol-glycoside aus Rosenblüten

Note on Ellagitannins and Flavonol Glycosides from Rose Petals Petals from two garden roses proved to be very rich in ellagitannins and flavonol glycosides. Rutin ( 1 ), spiraeoside ( 2 ), quercitrin ( 3 ), isoquercitrin ( 4 ), nicotiflorin ( 5 ), eugeniin ( 6 ), rugosin A (7), rugosin D ( 10 ), casuarictin ( 8 ), and tellimagrandin I (9) were isolated. Spiraeoside, at physiological pH, exerts a pronounced stabilisation of the anthocyanin colour with enhancement of extinction and bathochromic shift of the absorption maximum in the visible range. The abundance of gallic-acid derivatives 6–10 is in contrast to the apparent inability of rose flowers to produce anthocyanins with a trihydroxylated ring B , a prerequisite in breeding true blue-coloured roses.     

Notiz über die Photoelektronen-Spektren des Nortricyclens und des Triasterans

The photocelectron spectra of nortricyclene (=tricyclo[2.2.1.0^2,6]heptane) and of triasterane (=tetracyclo[3.3.1.0^2,8.0^4,6]nonane) have been recorded and a tentative assignment of the bands has been put forward on the basis of MINDO/2 SCF calculations.     

α-Alkylierung von β-Hydroxycarbonsäuren über 1,3-Dioxan-4-on-Enolate

Highly Diastereoselective α-Alkylation of β-Hydroxycarboxylic Acids Through Lithium Enolates of 1,3-Dioxan-4-ones From serine, β-hydroxyisobutyric acid (‘Roche’ acid) and β-hydroxybutyric acid, the dioxanones 1–6 were prepared. The generation of the enolates of type I with LDA at ?75° and alkylation gave products with trans-configuration whereas protonation of the 5-methyl-substituted enolate allowed access to the cis-configurated β-hydroxybutyric-acid derivative 12 . Hydrolysis gave the free β-hydroxy acids of ‘syn’-and ‘anti’-configuration. Alkylation of the 6-unsubstituted dioxanones 1 and 3 yielded predominantly products resulting from attack in the cis-position of the t-Bu group. The ‘reactive’ conformation of the enolates involved is tentatively derived from the product configuration. The selectivity of the alkylation is also discussed in terms of the results of an ab-initio calculation on the enolates M–P.     

Notiz über das System LilnO2/LiNiO2

In the system LiInO₂/LiNiO₂ there are on the LiInO₂-rich side several hitherto unknown phases.     

Notiz über einen Zugang zu β, γ-ungesättigten Carbonsäurederivaten mit Hilfe der Amidacetal-Claisenumlagerung. Über synthetische methoden, 17. Mitteilung

Note on a preparation of β, γ-unsaturated carboxylic acid derivatives using the amide acetal Claisen rearrangement 3-(Trimethylsilyl)allyl alcohols smoothly undergo the amide acetal Claisen rearrangement furnishing allyl silanes. Subsequent protolysis with HF at ?20° provides a convenient, stereoselective method for the preparation of β, γ-unsaturated carboxylic acid derivatives. Three model examples illustrate the procedure.