15min:

THOMAS J. PRESTON, MAITREYA DUTTA, BRIAN J. ESSELMAN, MICHAEL A. SHALOSKI, ROBERT J. MCMAHON AND F. FLEMING CRIM, The University of Wisconsin-Madison Department of Chemistry, 1101 University Avenue, Madison, WI, 53705; AIMABLE KALUME, LISA GEORGE AND SCOTT A. REID, Department of Chemistry, Marquette University, Milwaukee, WI, 53233.

Photodissociation of species entrained in solid matrices potentially leads to reassociation of the newly formed fragments. After fixing CH₂ClI in various atomic and molecular matrices, we measure ultrafast transient absorptions to monitor the photolysis of the precursor and isomerization to form iso -CH₂ClI. We probe the two lowest energy electronic absorption features of CH₂Cl-I near 435 nm and 800 nm. Probing the low energy side of the 435-nm band interrogates the formation and subsequent cooling of the hot, newly formed products. We find that the recoiling fragments, CH₂Cl and I, lose large amounts of energy to the environment in the initial collision with the matrix cage, which leads to formation of the isomer.