Picosecond laser photolysis studies on photoinduced electron transfer processes in poly(1-vinylpyrene) in solutions

The primary processes of photoinduced electron transfer (ET) dynamics in poly(1-vinylpyrene) (PVPy) doped with electron acceptors were investigated by means of picosecond transient absorption measurement in solutions with different polarities. The simple scheme (Scheme 1) based on a one-dimensional random walk model that the cation radical continuously migrates along pendant aromatic moieties in the polymer chain interprets the hole transfer (HT) dynamics in the longer delay time after the excitation. However, in the early stage, the deviation observed due to the dimer cation formation, which acts as a trap site for the cation and a very slow HT process occurred as a result of a detrapping process. By integrating the present results with the previous investigation on other aromatic vinyl polymers, the role of the dimer cation on the hole migration process along the polymer chain were discussed.