DIRECT OBSERVATION OF SPIN-FORBIDDEN FORMATION OF O(D-1) IN THE NEAR-UV PHOTOLYSIS OF OZONE

Time-of flight measurements have been made of the O(D-1) fragment foll owing the photolysis of ozone in the near-UV. At 321.9 nm fragments ar e seen with kinetic energies the values of which are those expected fr om spin-forbidden dissociation with ground state O-2(X-3 Sigma(g)(-)) molecules as the co-product. Spin-allowed dissociation of internally e xcited ozone molecules is also seen to produce translationally cold O( D-1) and O-2(a(1) Delta(g)) products. The implications for the dissoci ation of tropospheric atone are briefly discussed. (C) 1997 Elsevier S cience B.V.