The observation of the Δm = 1 transitions of the triplet states of randomly oriented molecules by electron spin resonance (ESR) is discussed. The shape of the absorption curve permits the ready determination of the zero-field parameters from the spectrum. In a derivative presentation, the widths of the lines observed give direct information on environmental and hyperfine broadening. Computer simulations of triplet spectra are presented. Good agreement is found with the observed spectra of phosphorescent and ground-state triplets.

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K. W. Wagner's treatment of the distribution of relaxation times in dielectrics is reviewed; the effect of the density of distribution upon the frequency variation of the dielectric constant and dielectric loss factor is discussed; and a graphical method of evaluating the constants of Wagner's equation from experimental data is described. These constants have been evaluated for a number of typical dielectrics, and the frequency variations of the dielectric constant and dielectric loss factor as computed from Wagner's equations and from the simple equations for a single relaxation time are compared with the observed behavior. The quantitative correlation obtained between Wagner's equations and the experimental data investigated is viewed as a confirmation of Wagner's theory of a statistical distribution of relaxation times in dielectrics.

We wish to report the observation, by electron paramagnetic resonance, of the ground-state triplets diazomethylene, :C=N+=N-(I); cyanonitrene, N=C-N (II); and dicyanomethylene, N=C-C-C=N (III).