Molecular-Beam Magnetic-Resonance Studies of the Nitrogen Molecule

Abstract

The radio-frequency spectra corresponding to the reorientations of the ${\mathrm{N}}^{15}$ nuclear moment and the molecular rotational magnetic moment have been studied in ${\mathrm{N}}_2^{15}$ by the molecular-beam magnetic-resonance method. A magnetic-resonance molecular-beam apparatus with an electron-bombardment detector was used for the experiments. In order to study these small moments, very narrow multiple slits were employed. The intensity of the molecular beam was maintained at the normal level through the use of multiple beams. From an analysis of the ${\mathrm{N}}^{15}$ resonance, the magnitude of the spin-rotational constant for the ${\mathrm{N}}^{15}$ nucleus was determined to be 22±1 kc/sec. This result can be shown to be consistent with available nitrogen chemical-shift data when the sign of the spin-rotational constant is positive. The magnitude of the rotational magnetic moment was found to be 0.2593±0.0005 nuclear magnetons per rotational quantum number.