The distinct absorption peaks in the solution spectrum of
D1eD5 andTPA-Rare described by the RVS RI-ADC(2)-calculations
as a mixed pi-pi*/charge-transfer excitation. The second excited
states of D1eD5 andTPA-Rare dark excited states of the acceptor
unit in the near UV region. Calculated ionization potentials reproduce the experimental values up to 0.2 eV for D1eD5 and up to
0.3 eV forTPA-R. The excitation energies of D1eD5 are reproduced
up to 7 nm, and forTPA-Rup to 24 nm.