Chlorine–Fluorine System at Low Temperatures: Characterization of the ClF2 Radical

Near‐ultraviolet photolysis of matrix (N2 or Ar)‐isolated chlorine trifluoride (ClF3) or mixtures of chlorine monofluoride (ClF) and fluorine at 16°K results in the production of a new infrared absorption at ∼ 575 cm−1. This band is assigned to the asymmetric stretching vibration of the chlorine difluoride (ClF2) free radical on the basis of the chemistry of the system, temperature dependence of the band intensity, and results of isotopic labeling. Much weaker bands, assigned to the symmetric stretching vibration and to the bending motion, are observed at 536 and 242 cm−1, respectively. The apex angle and force constants are calculated from the data.