Transient carbonyl nitrenes RC(O)N, formed during thermal-or photoinduced decomposition of carbonyl azides RC(O)N3, are highly liable to the Curtius rearrangement, producing isocyanates RNCO in almost quantitative yield. Contrary to common belief, we found a thermally persistent triplet carbonyl nitrene, FC (

The dipolar oxathiazyne-like sulfinylnitrene RS(O)N, a highly reactive α-oxo nitrene, has been rarely investigated. Upon flash vacuum pyrolysis of sulfinyl azide CF3S(O)N3 at 350 °C, an elusive sulfinylnitrene CF3S(O)N was generated in the gas phase in its singlet ground state and was characterized by matrix-isolation IR spectroscopy. Further fragmentation of CF3S(O)N at 600 °C produced CF3 and a novel iminyl radical OSN, an SO2 analogue, which were unambiguously identified by IR spectroscopy. Consistent with the experimental observations, DFT calculations clearly support a stepwise decomposition mechanism of CF3S(O)N3.

The methylsulfonyloxyl radical, CH3SO3, one of the key intermediates in the atmospheric oxidation of dimethyl sulfide (DMS), was generated by flash pyrolysis of CH3SO2OOSO2CH3 and subsequently isolated in solid noble-gas matrices. The radical has been characterized by UV/Vis and IR spectroscopy and its tautomerization to CH2SO3H observed upon irradiation with light of λ≥360 nm.

The stepwise decomposition of fluorophosphoryl diazide (FP(O)(N3)2), via nitrene (FP(O)(N3)N) and the cyclic intermediate (FP(O)N2), was experimentally and theoretically studied.