抄録
Pure quadrupole spectra of N14 in para-bromoaniline, para-chloroaniline, para-phenylenediamine, and urea were obtained. From the spectra quadrupole coupling constants and asymmetry parameters were determined. The apparent intensity of the high frequency line was always greater than that of the low frequency line when the method of Zeeman modulation was applied. This fact was interpreted from the second-order perturbation theory of Zeeman effect. By using the method of frequency modulation, the intensity difference between two lines became so small as it was interpreted with the population-difference between each state. The principal axis system of nitrogen in para-bromoaniline was determined with Zeeman studies. Discussions supported that the three bonds about nitrogen in these compounds are coplanar with the plane of benzen ring.
