Determination of the O–IO bond dissociation energy by photofragment excitation spectroscopy

Pulsed laser photolysis combined with laser induced fluorescence of IO has been used to study the photofragment excitation spectrum of OIO. Analysis of the O–IO dissociation threshold observed around 480 nm provides the first experimental determinations of the OIO bond dissociation energy and heat of formation at 298 K, which are given by D 0 ∘ ( O – IO ) = ( 248.8 ± 1.0 ) kJ mol - 1 and Δ f H 298 ∘ ( OIO ) = ( 118.5 ± 2.0 ) kJ mol - 1 , respectively.