VERIFICATION OF THE SMOLUCHOWSKI EQUATION FOR VISCOUS SOLVENTS.

The experimental data needed to verify the applicability of the Smoluchowski equation in the calculation of the rate constant for donor to acceptor electronic energy transfer in n-hexadecane was obtained. This data was the quenching constant, the mean lifetime of the donors excited state and the diffusion coefficients for donor and acceptor molecules in n-hexadecane. From the data obtained for three of the systems investigated, it was found that the Smoluchowski equation is a valid method for the calculation of the rate constant. For example, the experimental values of the rate constants for naphthalene, phenanthrene and chrysene were 12.1, 9.5 and 18.1 x 10 to the 9th power litermolesecond as compared with the values 11.0, 12.5 and 16.7 x 10 to the 9th power litermolesecond as calculated by means of the Smoluchowski equation. The values of the rate constants predicted by the Debye and Porter modifications of the Smoluchowski equation were 2.4 and 3.6 x 10 to the 9th power litermolesecond, respectively. Author