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

JS Wilson, N Chawdhury, MRA Al-Mandhary, M Younus, MS Khan, PR Raithby, A Köhler, RH Friend

J. Am. Chem. Soc. 123 (2001) 9412-9417.

The energy gap law established for aromatic hydrocarbons and rare earth ions relates the nonradiative decay rate to the energy gap of a transition through a multiphonon emission process. We show that this energy gap law can be applied to the phosphoresce of a series of conjugated polymers and monomers for which the radiative decay rate has been enhanced through incorporation of a heavy metal. We find that the nonradiative decay rate from the triplet state T1increases exponentially with decreasing T1-S0 gap for the polymers and monomers at 300 and 20 K. Comparison of the nonradiative decay of polymers with that of their corresponding monomers highlights the role of electron-lattice coupling.