Hydrolysis of substituted 8-acetoxyquinolines

In the absence of metal ions, the hydrolysis of 2-methyl-8-acetoxyquinoline and of 5-chloro-8-acetoxyquinoline follow the same reaction paths as those of the parent ester 8-acetoxyquinoline, including an intramolecular catalysis by the quinoline nitrogen. Unlike the hydrolysis of the other esters, that of the 2-methyl compound appears not to be catalysed by metal ions, and this is consistent with the view that catalysis by a metal ion involves the formation of a 7-membered chelate structure.     

Precipitation of copper 8-hydroxyquinaldate from homogeneous solution

Copper can be precipitated quantitatively, over a wide range of pH, by 8-hydroxyquinaldine produced from the hydrolysis of 8-acetoxyquinaldine. The copper 8-hydroxyquinaldate can be weighed as either the monohydrate or the anhydrous dichelate. Differences in the appropriate pH conditions, between the PFHS and conventional precipitation methods, and between thorium and copper precipitations from homogeneous solution, are accounted for.     

Thermal diffusion of dilute aqueous Na2MgEDTA and Na2CaEDTA solutions at 25°C

The Soret effect in dilute aqueous solutions (0.01–0.1m) of Na₂MgEDTA and Na₂CaEDTA is investigated using the flow-cell method. The Soret coefficients obtained from thermal diffusion experiments conducted at 25°C are reported. Heats of transport have been estimated based on the Debye-Hückel theory and the molar entropies of transport, calculated. Results of the present work have been compared with the Soret data for MgCl₂ and CaCl₂. It is suggested that the solvent exchange effect may account for the differences in the Soret effect observed between the pairs (Mg⁺², Ca⁺²) and (MgEDTA^–2, CaEDTA^–2).