I-ASTERISK PRODUCTION FROM N-ALKYL IODIDES AT 222 NM

The dynamics of I (P-2(1/2)) production in a series of n-alkyl iodide s at 222 nm have been investigated. Data are analyzed using a simple c lassical impulsive model. At this excitation wavelength, I(P-2(3/2)) o riginates from a curve-crossing between the (3)Q(0) and (1)Q(1) surfac es and the probability of crossing for all the iodides has been derive d. Since the I quantum yield is found to decrease, the probability of crossing increases as a function of the alkyl radical size, which is also consistent with the classical model.