Photochemically induced intramolecular six-electron reductive elimination and oxidative addition of nitric oxide by the nitridoosmate(VIII) anion.

UV photolysis of the nitridoosmate(VIII) anion, OsO3N , in low-temperature frozen matrices results in nitrogen-oxygen bond formation to give the Os-II nitrosyl complex OsO2(NO)(-) Photolysis of the Os-II nitrosyl product with visible wavelengths results in reversion to the parent Os-VIII complex. Formally a six-electron reductive elimination and oxidative addition, respectively, this represents the first reported example of such an intramolecular transformation. DFT modelling of this reaction proceeds through a step-wise mechanism taking place through a side-on nitroxyl Os-VI intermediate, OsO2(eta(2)-NO)(-).