DIELECTRIC-RELAXATION OF SOME ANTIMICROBIAL AGENTS

The dielectric loss DELTAepsilon''/x for some phthalazinone derivative s was measured in dioxane solutions in the frequency range 0.2-18 GHz at 20-degrees-C. The data were analysed using Debye equation. Three De bye terms were obtained. The first term in the lower frequency range c ould be attributed to the molecule as a whole while the second and thi rd terms related to the inner mobility of such molecules. The second t erm could be attributed to the flexibility of the molecules while the third one is due to the orientation of the side group or to the Poley absorption resonance which is reasonable for the liberation of dipoles damped by soft collision. Contributions of these terms are found to b e related with the biological activity of the investigated compounds.