Our previous study 32 largely focused on the static properties of the valence excitations to explore the ISC dynamics. In this investigation, we have expanded on that approach by incorporating a dynamic perspective. The energy differences between relevant states are derived from the non-adiabatic simulations and displayed in Figures and. Each panel presents a comparison of the three isomers within a given model. The average values across all simulated trajectories are represented by solid thick lines, and the corresponding standard deviation is indicated by the shaded regions. In the earlier study, the slower IC rate observed in 4-TP compared to 2-TP was attributed to the larger energy gap between S 1 and S 2 in the para isomer. That conclusion was based on the static features of the valence excitation in the implicit model. The dynamic picture now offers a similar explanation. The dynamic energy profiles of TP aceto impl isomers, as presented in Figure , reveal that the S 1 /S 2 energy separation is smallest in 2TP, followed by 3-TP, and largest in 4-TP. With regard to the ISC transitions, we notice a smaller energy separation between the S 1 and T 2 states in all isomers. On the other hand, the S 1 and T 3 states are more separated in the para isomer compared to the ortho and meta isomers, in both gas-phase and solvated models. Despite having a small ∆E ST along the S 1 /T 2 channel, the rate of ISC differs across the isomers. An explanation for this can be found in the nature of the singlet/triplet transitions. tation, the states are sorted according to their orbital nature, as stated in Tables and. Since the primary focus is on the energy differences between singlet and triplet states, such classification is enough to effectively capture the key outcomes. Thus, the energy profiles from Figure have been rearranged to distinguish El-Sayed allowed transitions, e.g. The S 1 /T 2 and S 1 /T 3 transitions in 4-TP are characterized by El-Sayed forbidden and El-Sayed allowed transitions, respectively, with the former serving as the dominant one. While the El-Sayed forbidden pathway enables only a restricted singlet/triplet crossing, it may change in the event of vibronic interactions and small energy separation between states. Such interactions are associated with mixing between states under the same multiplicity but of different characters, facilitating spin-orbit coupling with vibronic coupling in singlet or triplet manifold. This allows for enhancing the spin-orbit coupling between the involved singlet/triplet states, thereby accelerating the ISC rate. In this study, we aimed to investigate the potential for such state interaction. In the excited-state dynamics of all three isomers, multiple out-of-plane vibrations are identified as active, making it challenging to effectively distinguish those associated with vibronic coupling. Thus, an alternative approach was adopted to estimate the likelihood of such couplings by examining the energy proximity between adiabatic states of the same multiplicity within the dynamic profiles.