Darstellung und Kristallstruktur von TICu[CuO2]

Investigations on Electronically Conducting Oxide Systems. XVI. Solid Solutions and Conductivity in the System MgTi₂O₅? Ti₃O₅ Solid solution formation is reported for the system Mg_1–xTi_2–x^IVTi_2x^IIIO₅. With increasing x there is at room temperature a transition from the orthorhombic pseudobrookite structure to the monoclinic low-temperature modification of Ti₃O₅. The X-ray diffraction pattern results are supported by DSC measurements, electrical and magnetic investigations. The tendency of Ti? Ti pair formation in the low-temperature Ti₃O₅ structure is accompanied by a drop of the activation energy for electrical conductivity and a decreasing susceptibility at high Ti^III concentrations.     

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. IX. Zur Struktur der GeS/GeS2- und GeSe/GeSe2-Gläser

Glass Formation and Properties of Chalcogenide Systems. IX. On the Structure of GeS/GeS₂ and GeSe/GeSe₂ Glasses Mole volume, glass transition temperature, and coefficient of thermal expansion were measured on glasses prepared by standardized conditions. Near the composition Ge₂S₃ and Ge₂Se₃ the properties show a singularity or point of inflexion, respectively. Random models of structure are inconsistent with such a behaviour. A model of higher chemical order is proposed which can explain the observed dependence of the glass properties on composition and is in accordance with radial distribution studies.     

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. XXVIII. Zur Bindungsenergie der Si?Si- und Ge?Ge-Bindung in den Verbindungen Na6Si2X6 und Na6Ge2X6 (X = S,Se)

About Glas Formation and Properties of Chalcogenide Systems. XXVIII. On Bonding Energies of Si? Si and Ge? Ge Bonds in Na₆Si₂X₆ and Na₆Ge₂X₆ (X = S, Se) Potentiometric titration of 0.01 molar solutions of Na₆Si₂S₆, Na₆Si₂Se₆, Na₆Ge₂S₆, and Na₆Ge₂Se₆ in methanol with bromine yields the thermodynamic data of the reactions which take place under scission of the Si—Si or Ge—Ge bonds, respectively. The bonding energies of these homonuclear bonds are estimated and compared with data from the literature.     

Herstellung keramischer Pulver. II. Über die Bildung von Mg2TiO4, MgTiO3 und MgTi2O5 durch Hydrolyse von 2-Ethoxyethylaten

Preparation of Ceramic Powders. II. Mg₂TiO₄, MgTiO₃, and MgTi₂O₅ Formed by Hydrolysis of 2-Ethoxyethylates Solutions of 2-ethoxyethylates of magnesium and titanium in 2-ethoxyethanol submitted to hydrolysis, evaporation and heating of the residue up to 450°C allow to prepare Mg₂TiO₄, MgTiO₃, and MgTi₂O₅ in an amorphous state with smaller than 1% of volatile components. Highly dispersed powders showing an increased sintering activity are obtained as a result of recrystallization. Mg₂TiO₄ is formed as inverse spinel phase in a metastable state.     

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. XIII. Über die Verbindungen Na6Ge2S6 · 4 CH3OH und Na6Ge2Se6 · 4 CH3OH

Glass Formation and Properties of Chalcogenide Systems. XIII. On the Compounds Na₆Ge₂S₆ · 4 CH₃OH and Na₆Ge₂Se₆ · 4 CH₃OH The glasses Ge₂S₃ and Ge₂Se₃ are soluble in solutions of Na₂S or Na₂Se in CH₃OH forming Na₆Ge₂S₆ · 4 CH₃OH and Na₆Ge₂Se₆ · 4 CH₃OH. On heating the CH₃OH-free substances are formed. From the i.r. and Raman spectra can de seen that the structure of the ions Ge₂S, Ge₂Se, P₂S₆^4?, and of Si₂Cl₆ is of the same type. The formation of the compounds can be regarded as a chemical proof for the existence of [Ge₂S₆] and [Ge₂Se₆] units as structural groups in the glasses Ge₂S₃ and Ge₂Se₃.     

Amidrazones. VII. Formation of s-triazines by thermolysis of N1-benzyl-substituted amidrazone ylides

The preparation of ylides of the general structure is described. Thermolysis of 14a (R = CH₃, R' = H, Ar = C₆H₅) gave dimethylamine and 2,4-dimethyl-6-phenyl-s-triazine. Thermolysis of ylides 14b (R = C₆H₅; R' = CH₃, Ar = C₆H₅) and 14c (R = C₆H₅, R' = CH₃, Ar = p-tolyl) gave dimethylamine, ArCH = NCH₃ and 1-methyl-2-Ar-4,6-diphenyl-1,2-dihydro-s-triazines ( 19a,b ). Triazines 19a and 19b were also prepared by condensation of N-methylbenzamidine with benzaldehyde and p-tolualdehyde, respectively. Thermolysis of 14d (R = C₆H₅, R¹ = CH₂C₆H₅,Ar = C₆H₅) gave 1-benzyl-2,4,6-triphenyl-1,2-dihydro-s-triazine ( 19c ) and N-benzylidenebenzylamine. Mechanistic aspects of these reactions are discussed.     

Glass formation and structure of chalcogenide systems XXIV. The model of charged dangling bonds in liquid and vitreous inorganic systems

Remarkable progress in understanding the nature of non-crystalline solids results from the constitutional intrinsic disorder of glass forming oxides and chalcogenides which has been found to consist predominantly of positively and negatively charged defect centres. Such disorder is a feature of condensed substances formed of atoms possessing non-bonding lone pair electrons. It is shown that the concept of charged dangling bonds has a much larger range of validity than for the above mentioned oxides and chalcogenides. It is a part of well known chemical experience. The model can be applied to halogens and interhalogen compounds as well as to polar solvents and systems which show bond isomerism. Also, the negative value of the effective electron correlation energy is a precondition for disproportionation in chemical bond systems.