SOME DIATOMIC AND TRIATOMIC FREE RADICALS TRAPPED AT $4.2^{\circ} K$

Author Institution: Department of Chemistry, The Johns Hopkins University“The radicals $NH_{2}$, $HNO_{3}$, $NO_{2}, NH, OH, C_{3}$ and CH have been trapped at $4.2^{\circ} K$ from the products of an electrical discharge sustained in argon as matrix material mixed with a small amount of the appropriate parent molecule. These species can be conclusively identified by their well known electronic absorption spectra. Because of environmental perturbations of the electronic states and to a lesser extent the vibrational levels, red and blue “matrix shifts” of upward to $300 cm^{-1}$ occur. The absorption “bands” of $NH_{2}$ are exceedingly sharp ($