Charge transfer properties of a donor–acceptor dyad based on an expanded acridinium cation

Photophysical properties of a donor–acceptor dyad are discussed, which is based on an N,N-dimethylaniline subunit connected to an expanded acridinium cation. Ground-state charge transfer results in the appearance of a moderately intense absorption band in the visible region. The peak maximum shifts to shorter wavelength (higher energy) with an increase in solvent polarity. Excitation of the compound in MeCN or DCE results in ultrafast (<1 ps) charge shift to place positive charge on the N,N-dimethylaniline, and is followed by the charge recombination in the 10–200 ps time domain.