Correcting the record: hydrogen sharing between two nitroxyl radicals in the gas phase with in situ synthesis of the corresponding hydroxylamines.

The TEMPONE (4-oxo-TEMPO) radical exhibits an infrared OH stretching spectrum upon heating it in helium gas on a molecular sieve, followed by co-expansion of the gas mixture into a vacuum chamber. The generated jet-cooled hydroxylamine TEMPONE-H aggregates with a second TEMPONE unit to form energetically comparable CO and N-O bound OH complexes. A computational re-investigation of the corresponding complexes based on TEMPO reveals a newly postulated global minimum structure for the TEMPO-H complex with TEMPO, which provides a more consistent spectral agreement between theory and experiment for a hydrogen atom shared by two nitroxyl radicals.