Dynamics of I*(2P1/2) production from fluorinated alkyl iodides at 266, 280, and ~305 nm

Kavita, K and Das, Puspendu K (2000) Dynamics of I*(2P1/2) production from fluorinated alkyl iodides at 266, 280, and ~305 nm. In: Journal of Chemical Physics, 112 (19). pp. 8426-8431.

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Abstract

In this paper, we present I*(2P1/2) quantum yield, phi* from the gas phase photodissociation of a series of perfluoroalkyl iodides at three different wavelengths 266, 280, and ~305 nm. The iodine atoms in the ground I(2P3/2) and spin-orbit excited I*(2P1/2) states were monitored directly by a two photon laser induced fluorescence scheme. The I* quantum yields for the fluorinated alkyl iodides are found to be much higher than their corresponding alkyl iodide analogs over the entire A band. However,phi* remains more or less unchanged as a function of photolysis wavelength for the perfluoroalkyl iodides with the exception of CF3I in which it drops monotonically as a function of wavelength. Unlike in normal alkyl iodides, branching at the alpha position does not affect the phi* in perfluoroalkyl iodides. The prediction of I* yield using the one dimensional Landau-Zener soft-radical-impulse model is opposite to what is seen from our measurements. In all the fluorinated alkyl iodides, the CF3 in-plane rocking mode which can take the initially excited 3Q0 state to the 1Q1 state through the crossing region appears to be weakly coupled to the C-I stretch resulting in low yield of I atom in the dissociation process.

Item Type:	Journal Article
Publication:	Journal of Chemical Physics
Publisher:	American Institute of Physics
Additional Information:	Copyright for this article belongs to American Institute of Physics (AIP).
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	13 Dec 2004
Last Modified:	19 Sep 2010 04:17
URI:	http://eprints.iisc.ac.in/id/eprint/2423

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