The evolution of N2from solid NaN3during photolysis is shown to result from active sites located as deep as a few hundred lattice constants within the crystallites. These active sites diffuse to the free surface to produce N2, exhibiting a diffusion constant sim;10mdash;15cm2/sec. The absorption constant of NaN3for 2537hyphen;A radiation is measured to be about 1.8times;105/cm, and quantum efficiencies for photolysis are determined to be 0.040 for photolysis of the surface layer and 0.12 for equilibrium nitrogen evolution from a partially decomposed mass. The reaction is shown to be first order with respect to light intensity. A mechanism for photolysis is suggested based upon Thomas and Tompkins' exciton decomposition scheme.
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