3,4,5,6-tetrafluorophenylnitren-2-yl: A ground-state quartet triradical

Article abstract of DOI:10.1002/chem.200903285

The photochemistry of 2iodo-3,4,5,6-tetrafluorophenyl azide (7d) has been investigated in argon and neon matrices at 4 K, and the products characterized by IR and EPR spectroscopy. The primary photochemical step is loss of a nitrogen molecule and formation of phenyl nitrene 1d. Further irradiation with UV or visible light results in mixtures of Id with azirine 5d′ , ketenimine 6d′, nitreno radical 2d, and azirinyl radical 9. The relative amounts of these products strongly depend on the matrix and on the irradiation conditions. Nitreno radical 2d with a quartet ground state was characterized by EPR spectroscopy. Electronic structure calculations in combination with the experimental results allow for a detailed understanding of the properties of this unusual new type of organic high-spin molecules.