화학공학소재연구정보센터
Journal of Physical Chemistry A, Vol.113, No.32, 9057-9064, 2009
Photodissociation of 2-Iodoethanol within the A Band
The photodissociation of 2-iodoethanol was studied within the A (sigma* <- n) absorption band at several wavelengths between 253 and 298 nm, and the velocity distributions and angular distributions of the photofragments were characterized by using velocity-map ion imaging. The two dominant dissociation channels correspond to the production of the 2-hydroxyethyl radical, C2H4OH, and 1(P-2(3/2)) and I*(P-2(1/2)), and in both channels, approximately 50% of the available excess energy is partitioned into translational energy of the fragments. The branching fractions for the I and I* channels at 266 nm were determined by using a combination of (1) the translational energy distributions for the separate I and I* channels determined by two-photon resonant, three-photon ionization, (2) the distributions for the combined I + I* channels determined by single-photon ionization at 118 nm, and (3) the relative photoionization cross sections of I and I* at 118 nm. Evidence was observed for either the secondary decomposition of C2H4OH, the photodissociation of C2H4OH, or the dissociative ionization of the C2H4OH radicals produced in the I channel. These mechanisms are also discussed.