The energy distribution, angular distribution, and alignment of the O(D-1(2)) fragment from the photodissociation of ozone between 235 and 305 nm

Resonance-enhanced multiphoton ionization and time-of-flight product imagin g have been used to study the O-3((X) over tilde (1)A(1))+h nu-->O(D-1(2))O-2((1)Delta (g)) channel of the UV photodissociation of ozone at 235, 245, 255, 265, 275, 285, 298, and 305 nm. At all wavelengths, the vibrational p opulations, the spatial anisotropy parameter beta, and the O(D-1(2))\m(j)\ populations were determined. The corresponding vibrational populations of O -2((1)Delta (g)) were peaked at v=0. The spatial anisotropy parameter was d etermined for each vibrational level and changed monotonically from about 1 .2 at 235 nm to 1.7 at 298 nm. At all wavelengths, \m(j)\ populations were peaked at \m(j)\=0. A full density matrix method was used to determine the a(q)((2))(p) parameters at 255 and 298 nm, where most of the signal was fou nd to be from parallel, incoherent excitation. The data support a dissociat ion mechanism in which excitation occurs to a state of A(') symmetry and th ere is substantial bending of the ozone before dissociation. (C) 2001 Ameri can Institute of Physics.