THE REACTION OF CS(8(2)P) AND CS(9(2)P) WITH HYDROGEN MOLECULES

The reactions of Cs(n(2)P(J)), n = 8, 9, J = 1/2, 3/2 with H-2 were st udied by laser induced fluorescence of the nascent product. No differe nce was found in the reactivity of the J = 1/2 and 3/2 states. The ene rgies available to the reaction products were 11.5 and 16.9 kcal/mol f or the n = 8 and 9 states, respectively. CsH was found in the nu=0 and 1 states but could not be detected in any higher vibrational state. T he nu=0/nu=1 population ratios were 1/0.33 (n=8) and 1/0.42 (n=9). The products rotational temperatures were approximately the same as the a mbient temperature of the reaction cell. Thus about 90% of the availab le energy is released as translation. From these data the following pi cture is derived. The mechanism is a primarily collinear abstraction a nd not an insertion. The large translational energy release is caused by a sudden switching on of repulsion when the H atoms are still close to each other. The reaction involves electron transfer, but at Cs-H d istances not far from the equilibrium bond length and is therefore not a harpoon reaction in the usual sense. (C) 1996 American Institute of Physics.