Hyperfine Structure in the Spectrum ofN14H3. I. Experimental Results

The structure of the hyperfine spectrum of ${\mathrm{N}}^{14}$ ${\mathrm{H}}_3$ in the microwave region has been carefully re-examined. It has been found that the ${\mathrm{N}}^{14}$ quadrupole line spacings for $K\ne 1$ can be fitted within experimental error to previously developed theory, provided a small change in the quadrupole coupling constant $\mathrm{eqQ}$ due to centrifugal distortion of the molecule is allowed for. For $K=1\mathrm{}$; and $J=2, 3, 4$, a doubling of each line of the quadrupole pattern has been found which increases from about 70 to 150 kc/sec with increasing $J$. It has been possible to explain these new features of the spectrum in terms of the interactions of the magnetic moments of the protons with the molecular magnetic field caused by rotation and with the magnetic moment of the ${\mathrm{N}}^{14}$ nucleus.