Hole resonance among more than two chromophores for the radical cationic carbazole (CZ) group of polyt/V-vinylcarbazole) (PVCZ) in solution was shown by the radical ion transfer method and charge resonance (CR) band measurements. The sample was PVCZ with its oligomers (degree of polymerization (DP) = 2-100). The hole transfer rate from the radical cationic CZ of the oligomers to a 2,5-dimethoxyaniline, which has a lower ionization potential than the CZ chromophore, decreased with an increase in the oligomer molecular weight due to the hole resonance among neighboring chromophores. Thus, the stabilization energy of iV-vinylcarbazole oligomers increases with increase in DP. The peak position of the CR band can be a good measure of the degree of charge resonance.The peak wavelength of the CR band was red-shifted for the larger molecular weight oligomers. This shift also suggested the existence of charge resonance in PVCZ among more than two CZ chromophores.

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