1973 Volume 46 Issue 10 Pages 2992-2997
The ultrasonic absorptions in aqueous solutions of amylamine were measured in the frequency range of 3.5–220 MHz and in the concentration range of 0.01–3.06 M. Two kinds of relaxations were observed. One was attributed to the 5A–A5 reaction of non-ionized molecules of amylamine, and the rate constants were determined from the concentration dependence of the relaxation time at various temperatures. The thermodynamic parameters were determined from the temperature dependence of the rate and equilibrium constants. The other was attributed to hydrolysis, which is a diffusion-controlled reaction. In order to clarify the relation between the stability of the aggregate and the length of the hydrophobic group, the ultrasonic absorptions in aqueous solutions of propylamine were also measured. The excess absorption due to the association-dissociation reaction was not observed; only that due to hydrolysis was observed. It was deduced from this investigation that the aggregate formed by the hydrophobic bonding exists in the aqueous solutions of normal amines, the carbon numbers of which are more than 4.
This article cannot obtain the latest cited-by information.