Molecular structures of inorganic compounds of low volatility: I. Salts of oxygen acids of the type M2XO4

We report an electron diffraction study of the molecular structure of gaseous cesium and thallium sulphates and cesium molybdate and tungstate. The average structure found for the M₂XO₄ molecules is described by a model (symmetry D_2d) in which the metal atoms bridge two edges of an XO₄ tetrahedron to form two 4-membered mutually perpendicular planar MO₂X rings.The data lead to conclusions on the complex nature of intramolecular motion. This motion may roughly correspond to great displacements of metal atoms on the surface of an imaginary sphere described near the tetrahedral acid residue.     

The role of Al3+ ions in alumino borate glasses as revealed by molar volume,refractive index and microhardness

An attempt has been made determine the types of Al³⁺ structural units in potassium alumino borate glass. Therefore a number of investigations have been carried out on the relation between the composition of the glasses and their properties. The density, refractive index, and hardness of a number of compositions in which Al₂O₃ replaces B₂O₃ at constant K₂O were measured. It appears that the replacement of B₂O₃is not entirely without some consequencies.The concentration of non-bridging oxygen ions increases with the introduction of Al₂O₃.Non bridging oxygen ions start aappearing at alkali concentration of about 0.2 mol K₂O.     

Cellular and foamed plastics as separation media A new geometrical form of the solid phase in analytical liquid-solid contact

There has been considerable interest during the last few years in using cellular (foamed) plastics (mainly polyurethanes) either unloaded or as a means of immobilizing hydrophobic organic reagents, powdered ion-exchangers or finely divided precipitates, for the collection and separation of inorganic or organic species from aqueous solution. Foamed plastics with anchored (bonded) functional groups have also been used for the same purpose. It has been realized that the application of cellular plastics is often advantageous not only for quantitative work but also for qualitative and semiquantitative analysis. Methods available on the application of cellular and foamed plastics for the collection, separation and recovery of various inorganic and organic components from aqueous solution are reviewed.     

Cycloaddition of diphenylnitrilimine to coumarins. The synthesis of 3a,9b-dihydro-4-oxo-1H-benzopyrano [4 ,3-c]pyrazole derivatives

The cycloaddition of diphenylnitrilimine to a series of coumarins occurs with the same regioselectivity in all cases, regardless the nature of the substituent present, to yield the corresponding 3a,9b-dihydro-4-oxo-lH-benzopyrano [4,3-c]pyrazoles $\text{4}$a–f. Dehydrogenation of $\text{4a}$ yields 4-oxo-1H-benzopyrano [4,3-c]-pyrazole $\text{6}$. In ethanolic sodium ethoxide solution, the reaction between coumarin and diphenylnitrilimine precursor, namely N-phenylbenzohydrazidoyl chloride $\text{1}$, affords no cycloadducts, but yields o-(β-ethoxycarbonylvinyl)phenyl N-phenylbenzohydrazidate $\text{10}$. The regiochemistry of the cycloadducts $\text{4}$a–f and the reaction sequence leading to $\text{10}$ are outlined. The structures of the products have been established by spectroscopic methods and independent syntheses wherever possible.