Notiz über die Kernresonanzspektren von trifluormethyl-substituierten Naphthalinderivaten

The proton and fluorine NMR. spectra of 25 trifluoromethyl substituted naphthalene derivatives have been analysed. The proton chemical shifts of the trifluoromethyl naphthylamines and naphthols have been correlated with calculated π-electron charge densities (PPP SCF).     

Über die Oxydation von Manganoxidhydroxid

The oxidation of γ-MnOOH (manganite) in oxygen and its disproportionation in HNO₃ lead topotactically to β-MnO₂. The oxidation of synthetic α-MnOOH (groutite) in oxygen depends on its cristallite size; finely divided crystals oxidise rapidly to Mn₅O₈ which usually is stable but yields β-MnO₂ by further oxidation. Larger crystals of disperse synthetic α-MnOOH are topotactically transformed to γ-MnO₂. In HNO₃ α-MnOOH disproportionates into γ-MnO₂ and Mn²⁺. Though strictly topotactical, the reaction α-MnOOH → γ-MnO₂ is not single-phase as might be expected. The discontinuity in the function: JAHN -TELLER distortion vs. reaction rate, may simply be interpreted as the crosspoint of two different functions attributed to the crystal species α-MnOOH and γ-MnO₂, respectively. This distortion confirms the presence of Mn³⁺ in manganite and nsutite. The wide variety of possible X ray powder patterns of the phase γ-MnO₂ is explained by the superposition of, (i) cristallite size broadening, (ii) intergrowth structure effects on the profile, and (iii) BRAGG angle shifts due to substitution of part of Mn⁴⁺ by Mn³⁺.     

Über die Hydrierung von Aminalen

The catalytic hydrogenation of aminals The catalytic hydrogenation of aminals, the bis-N-analogs of acetals, was investigated. 3-(γ-Aminopropyl)-piperidines are formed by the hydrogenolytic splitting of the C–N-bond of decahydro-1, 8-naphthyridines. The reaction is stereospecifically influenced by the catalyst used. Non cyclic aminals are hydrogenated in the same manner. The mass and NMR. Spectra of 3-(γ-aminopropyl)-piperidines are discussed.     

Über einige Umwandlungsprodukte des «BLIX-Sulfatids» und die Herstellung von quartären Dihydro-sphingosinium-Salzen

In the sulfatide fraction of beef spinal-cord, isolated according to the method of BLIX [9] and LEES [14], there are also sulfatides present derived from 2S, 3R-1, 3-dihydroxy-2-amino-octadecane.     

Über die Elektrokristallisation von Fulleriden

Electrocrystallization of Fullerides The fullerides P(C₆H₅)₄C₆₀ · P(C₆H₅)₄Cl, P(C₆H₅)₄C₆₀ · P(C₆H₅)₄Br und As(C₆H₅)₄C₆₀ · As(C₆H₅)₄Cl have been prepared by electrocrystallization. Single crystal structure determinations have shown them to be isostructural in space group I4/m with lattice constants a = 12.5731(9), c = 20.142(3) Å; a = 12.5378(10), c = 20.606(5) Å; a = 12.6003(11), c = 20.377(4) Å, respectively. Spectroscopic and magnetic investigations prove the existence of a C₆₀^? anion, showing orientational disorder in all three fullerides.     

Über die Struktur von geschmolzenem Selendioxid

About the Structure of Molten Selenium Dioxide The Raman spectra of molten and gaseous selenium dioxide are nearly identical. The number of bands indicates the existence of a temperature depending equilibrium of monomeric and dimeric selenium dioxide in the molten and the gaseous state. A chain structure as in the crystal could not be found. An oxygen-bridged planar ring seems most likely for the structure of the dimer. Broadening of bands two intense, polarized lines at ν = 955/966 cm^?1 indicate an equilibrium of the trans-(C_2h) with the cis-structure (C_2v).     

Über die photochemische Cyclisierung von 2-Allylphenolen

A series of 2-allyl-phenols and 2-but-3′-enyl-phenol were photochemically rearranged to the corresponding cyclic ethers. The isomer distribution was shown to be similar to that observed for the acid catalysed cyclisation.     

Über die Reaktion von Alkalihexafluorosilicaten mit Aluminiumoxid

On Reactions of Alkali Hexafluorosilicates with Aluminum Oxides The reaction of Na- and K-hexafluorosilicates and α- or γ-Al₂O₃ has been investigated. Final reaction products are fluoroaluminates and alumosilicates. The reaction mechanism has been discussed. Influence of reaction parameters like time, temperature, layer thickness, and the effect of admixtures (fluorides, SiO₂) have been regarded. Tablet-reactions show the introduction of reaction by Si? F species.     

Über die thermische Trimorphie von KGaCl4

On the Thermal Trimorphism of KGaCl₄ KGaCl₄ exists in three enantiotropic forms: KGaCl₄-I is stable below ?25°C, KGaCl₄-II between ?25 and about 130°C, KGaCl₄-III above 130°C up to the melting point (259°C). KGaCl₄-III belongs to the baryte type of structure, KGaCl₄-II crystallizes with the KAlCl₄-type (distorted baryte). Thermal expansion of both forms (II, III) and the phase transition II ? III are investigated thoroughly.     

Über die Chemisorption von Pyridinbasen an Metalldithiophosphinaten

On the Chemisorption of Pyridine Bases on Metal Dithiophosphinates The planar resp. tetrahedral metal dithiophosphinates Nil₂ ( 1 ) resp. CoL₂ ( 2 ) (L = CH₃(p-CH₃OC₆H(₄)P(S)S-) give well defined penta-or hexacoordinated adducts of the types ML₂B or ML₂B₂ with pyridine, methylpyridines or pyridine carboxylic acid esters. Enthalpies of the reaction were calorimetrically determined in some cases and the adsorption of the gaseous bases on solid 1 or 2 investigated by means of gas chromatography. The adsorption process could be satisfactorily described by LANGMUIR 's isotherme and the isosteric enthalpies of adsorption were found to 60–95 kj mol^?1. This and the observed parallelism between the “relative surface density” and the enthalpies of adduct formation as a relative measure for the bond strength M–B led to the conclusion that the bases are chemisorbed via coordinative bonds ever under the conditions of gas chromatography.     

Über die Matrixisolation von AsCl4F

Matrix Isolation of AsCl₄F The gasphase components during the sublimation of [AsCl₄]⁺[AsF₆]^? are characterized by means of mass and IR matrixisolation spectroscopy. The primary vaporization products are AsF₅ and the new halide AsCl₄F. The IR spectra of AsCl₄F and PCl₄F are compared and the calculated force constants are discussed. Other mixed halides of arsenic are formed under suitable conditions.     

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.