Elusive Fluoro Sulfinyl Nitrite, FS(O)NO, Produced by Photolysis of Matrix‐isolated FS(O) 2 N

Triplet fluoro sulfonyl nitrene, FS(O) 2 N ( X 3 A") was generated by ArF excimer laser irradiation ( λ = 193 nm) of FS(O) 2 N 3 isolated in solid noble gas matrices. The novel nitrene was characterized by IR ( 15 N‐, 18 O‐, and 34 S‐labeling), UV/Vis, and EPR spectroscopy. The elusive sulfinyl nitrite, FS(O)NO, was formed in a spin‐forbidden reaction upon photolysis ( λ > 320 nm) of triplet FS(O) 2 N. Triplet‐singlet intersystem crossing (ISC) was found to compete with a spin‐allowed fragmentation of the sulfonyl nitrene, which yields SO 2 + FN ( 3 Σ – ) and FNO + SO ( 3 Σ – ). Guided by DFT calculations the complex photo‐decomposition of FS(O) 2 N ( X 3 A") is discussed.