Response: Why had long-lived electron-transfer states of donor-substituted 10-methylacridinium ions been overlooked? Formation of the dimer radical cations detected in the near-IR region

Photoexcitation of an acetonitrile solution of the 9-(1-naphthyl)-10-methylacridinium ion results in formation of the electron-transfer state that forms the long-lived dimer radical cation with the acridinium ion, which was clearly detected as the transient absorption spectrum in the near-IR region.