Photochemical studies of IBr, ICl and BrCl by kinetic spectroscopy in the vacuum ultra-violet

Abstract

The flash photolyses of the interhalogen compounds IBr, lCl and BrCl have been investigated by kinetic spectroscopy in absorption in the vacuum ultra-violet. Direct observations on the atomic states resulting from primary photolytic processes have been correlated with the absorption spectra of these molecules. These atomic products are also discussed within the context of the strongly “avoided crossing” between the ³Π_o+ and 0₊ states and factors governing radiationless transitions. The kinetics of the halogen atoms, including electronically excited (²P_½) as well as ground state (²P_½) species, permits a discussion of a number of atomic reactions. Further observations on the absorption spectra on IBr and lCl in the vacuum ultra-violet revealed two new “Rydberg pairs” which are also reported.