Reversible Photoinitiated Isomerization Reaction of BrOBr to BrBrO: A Combined Matrix Isolation and ab Initio Study

The reversible photoinitiated isomerization reaction of BrOBr to BrBrO was measured in solid argon matrixes and calculated by multiconfigurational quasidegenerate perturbation theory (MCQDPT). The calculated vertical excitation energies are in good agreement with the experimentally observed excitation wavelengths. While the isomerization from BrOBr to BrBrO appears to be quantitative, some product loss is observed during the back reaction. The calculated excitation energies and oscillator strengths for transitions from the ground to excited states offer a detailed explanation of this behavior.