Spectroscopic Identification of H2NSO and syn‐ and anti‐HNSOH Radicals

: The simplest aminosulfinyl radical H2 NSO has been generated in the gas phase through flash vacuum pyrolysis of CF3 S(O)NH2 at approximately 1000 K. Upon UV light irradiation (365 nm), 1,3-H migration occurs in H2 NSO and furnishes an elusive N-amidyl radical HNSOH in syn and anti conformations in cryogenic matrices (N2 or Ar, 15 K). Further 266 nm laser irradiation results in dissociation of HNSOH to H2 O and SN and concomitant reformation of H2 NSO in trace amount. The identification of H2 NSO, syn-HNSOH, and anti-HNSOH by matrix-isolation IR spectroscopy is supported by high-level quantum chemical computations.