Formation of extremely long-lived charge-separated state by two-photon ionization in poly(N-vinylcarbazole) adsorbed on a macroreticular resin

Extremely long-lived (much greater than8 h) cationic species were observed following two-photon ionization in poly(N-vinyclar-bazole) as well as in it s monomer model, N-ethylcarbazole, adsorbed on a macroreticular resin, Ambe rlite XAD-8 at room temperature. The formation and deactivation of the long -lived charge-separated states were attributed to the trapping process of t he ejected electron and the cationic species fixing the rather large inter- ionic distance followed by long-distance back electron transfer in the ion pair. Based on the dynamic behaviors, the role of the hole migration result ing in an increase in the survival time of the cationic species in the poly mer system is discussed. (C) 2001 Elsevier Science B.V. All rights reserved .