Raman scattering from the iodine—durene complex

Abstract

The charge-transfer complex formation between iodine as an acceptor and durene as a donor has been investigated using Raman spectroscopy. The iodine was dissolved in dilute (0–3 volume%) mixtures of the donor in n-heptane used as an inert solvent. The kinetics of the complex can be simulated with a two-state Markov process model for the Raman lineshape of the free iodine—complexed iodine system. The model is formulated on the basis of the theories of Kubo, Gordon and Strauss. At low donor concentrations the non-reactive part of the line profile can be considered constant so that the reactive part of the profile can be separated out from the total lineshape. This operation is performed using iterative convolution of the Kubo—Gordon lineshape function with a reference spectrum measured at zero donor concentration. The lifetime can then be calculated from the iteratively determined best fit lineshape function. The lifetime of the complex at 300 K is 4·3_−1·0 ^+1·5 ps.