MECHANISMS OF FORMATION AND DEACTIVATION OF EXTREMELY LONG-LIVED CHARGE-SEPARATED STATE FOLLOWING PHOTOINDUCED ELECTRON-TRANSFER IN CARBAZOLYL POLYMERS COADSORBED WITH 1,2,4,5-TETRACYANOBENZENE ON MACRORETICULAR RESINS

At room temperature, extremely long-lived (>8 h) charge-separated (CS) states following photoinduced electron transfer were found for poly(N -vinylcarbazole) (PVCz) coadsorbed with 1,2,4,5-tetracyanobenzene as a n electron acceptor on a macroreticular resin, Amberlite XAD-8. The fo rmation of the long-lived CS states was ascribed to both a hole-migrat ion process along the polymer chain and a hole-trapping process result ing in the large interionic distance. The temperature dependence on th e decay profiles of the long-lived CS states indicated that the charge recombination due to the long-distance electron tunneling was respons ible for the disappearance of the CS states in the long time region. T he simulation curve taking account of both the long-distance electron transfer and the distribution of the interionic distance reproduced th e decay profiles of the CS states fairly well. The effects of both tac ticity of PVCz and the modification of the adsorbents on the formation and the deactivation processes of the long-lived CS states were exami ned. The results revealed that the deep hole-trap sites resulting in t he large interionic distance were not simply related to the carbazolyl dimer cation sites but to the carbazolyl moieties adsorbed in the vic inity of the polar ester groups in the adsorbent.