The Molecular Scattering of Light from Ammonia Solutions. The Fine Structure of a Vibrational Raman Band

Abstract

The Raman band of the ammonia molecule corresponding to the infrared absorption at 3 \ensuremath{\mu} has been partially resolved into its fine structure. The experiments have been made not with gaseous or liquid ammonia but with aqueous solutions of relatively high concentration. The lines have been assigned to $Q$, $P$, $R$, $\mathrm{PP}$, and $\mathrm{RR}$ branches, corresponding to changes in rotational quantum number $\ensuremath{\Delta}k=0, \ifmmode\pm\else\textpm\fi{}1, \mathrm{and} \ifmmode\pm\else\textpm\fi{}2$. The moment of inertia about a line normal to the axis of symmetry calculated from the spacing of the lines is I = 2.82\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}40}$ g ${\mathrm{cm}}^{2}$. As far as the present, somewhat incomplete results may be taken to indicate the structure of the N${\mathrm{H}}_{3}$ molecule is largely uninfluenced by the force fields of the solvent molecules.