Figure shows the highest occupied NTO (HONTO) and lowest unoccupied NTO (LUNTO) of the lowest singlet excited state, S1. In both the conformers, the transition orbitals are localized mainly at the PTZ moiety in HONTO and mainly at the TRZ moiety in LUNTO, indicating that both are CT excited states. The excited-state dipole moments for q-ax. and q-eq. were calculated to be 25.0 D and 22.6 D, respectively, which are in good agreement with the experimental values estimated from the Mataga-Lippert plots, 23.2 D and 20.8 D, respectively. Thus, we concluded that the large solvent dependence of emission spectra between the two conformers is not caused by the differences in their dipole moment.