Dynamics of Charge-Transfer State Formation in Supercritical Fluid Solvent

摘要

The rate of the intramolecular charge-transfer state formation has been determined for 4-(N, N-dimethylamino)- benzonitrile (DMABN) in supercritical CF_3H by means of a time-correlated single-photon counting technique. The rate constant increases rapidly with increasing CF_3H density, indicating the importance of the polar envi- Ronment offered by the CF_3H molecules which are clustering around a DMABN molecule. With increasing Clustering number, the activation barrier is lowered and hence the rate increases exponentially. The observation Is semiquantitatively interpreted on the basis of a molecular dynamics simulation of clustering in supercritical Solutions.