Knowledge Bank

We have applied the method of optical detection of magnetic resonance (ODMR) to a number of polycyclic aromatic hydrocarbons for the purpose of measuring the rates of intersystem crossing for the individual spin sub-levels of the triplet state. These findings, along with other data from the literature will be examined in an attempt Co offer a qualitative explanation of the triplet state dynamics observed. Our approach will be to utilize the descriptive framework proposed by Henry and $Siebrand1$ and Metz, et $al.2$ and recently employed by Antheunis, Schmidt and van der $Waals3$ to explain their results on nonradiative transitions in a series of nitrogen containing derivatives of anthracene. Our study suggests that nonradiative inter-system crossing may be qualitatively understood and predicted on the basin of spin orbit coupling interactions, energy levels, and the symmetry of the molecule. This analysis will be presented along with conclusions applicable to planar organic systems in general.