15min:
DYNAMICS OF THRESHOLD PHOTO-ION PAIR PRODUCTION IN SMALL MOLECULES.

JOHN W. HEPBURN, QICHI HU, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4.

It has already been demonstrated that the method of threshold ion-pair production spectroscopy (TIPPS) can be used to probe the energetics of molecular dissociation with spectroscopic accuracy. Since TIPPS produces a spectrum which measures energy differences between the starting neutral molecule states and the states of the ion-pair dissociation products, it can also be used to determine the spectroscopy of the ion fragments, and the dynamics of the ion-pair dissociation. The results of TIPPS experiments on the following dissociations will be used to illustrate these features of TIPPS:
H2S + h nu rightarrow H+ + SH-
H2S + h nu rightarrow H- + SH+
HCN + h nu rightarrow H+ + CN-
Our results on these systems indicate that, as with neutral photodissociation, an initial state of the neutral can be coupled to a wide range of product states, meaning that the spectroscopy of highly excited ions can be studied by TIPPS.