The energy gap law for triplet states in Pt-containing conjugated polymersand monomers

The energy gap law established for aromatic hydrocarbons and rare earth ion s relates the nonradiative decay rate to the energy gap of a transition thr ough a multiphonon emission process. We show that this energy gap law can b e applied to the phosphoresce of a series of conjugated polymers and monome rs for which the radiative decay rate has been enhanced through incorporati on of a heavy metal. We find that the nonradiative decay rate from the trip let state T-1 increases exponentially with decreasing T-1-S-0 gap for the p olymers and monomers at 300 and 20 K. Comparison of the nonradiative decay of polymers with that of their corresponding monomers highlights the role o f electron-lattice coupling.