Production of N3 upon photolysis of solid nitrogen at 3 K with synchrotron radiation.

The photodissociation of gaseous molecular nitrogen has been investigated intensively, but the corresponding knowledge in a solid phase is lacking. Irradiation of pure solid nitrogen at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of product l-N3 at 1657.8 and 1652.6 cm(-1). The threshold wavelength to generate l-N3 was determined to be (143.7±1.8) nm, corresponding to an energy of (8.63±0.11) eV. Quantum-chemical calculations support the formation of l-N3 from the reaction N2 +N2, possibly through an activated complex l-N4 upon photoexcitation with energy above 8.63 eV. The results provide a possible application to an understanding of the nitrogen cycle in astronomical environments.