General Equation for the Removal of Electronically Excited Halogen Atoms

General Equation for the Removal of Electronically Excited Halogen Atoms 

Before discussing individual results for spin orbit relaxation, a general framework for the kinetic treatment will be given. The rate of relaxation in a system involving only two states, 

The value of k2 is determined according to the principle of detailed balancing. For thermal energies less than or equal to 300°K, the last term in Eq. (48) may be neglected for the initial decay, provided a large excess of ground state atoms is not present (Table I). Thus the measured decay coefficients and data derived from these relate to k  

The over-all first-order decay coefficient (kx) may be broken down into a number of terms  

The homogeneous quenching of I(5 %) generated in the photolysis of CF3I is sufficiently slow so that the dominant term in Eq. (49) is apparently that due to diffusion to the walls of the reaction vessel (followed by efficient deactivation). Thus it is observed that as the total pressure of inert gas present is lowered, the rate of relaxation increases, showing an inverse first power relation27 (Fig. 11). The rate of diffusion to the vessel walls is given by the diffusion equation  

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