Given that the T 2 and T 3 states, which have different orbital characteristics, are the main participants in ISC, a significant emphasis is placed on their analysis. The valence excitations in Tables and Further investigation was conducted on the T 1 and T 2 states for a comprehensive comparison. The computed results revealed an interesting observation: unlike the preceding case, the energy separation between T 1 and T 2 is smallest for 4-TP, followed by 2-TP and 3-TP, as illustrated in Figure . However, the computed (T 2 /T 1 ) average for 4-TP remains higher than the (T 3 /T 2 ) averages determined for 2-TP and 3-TP. This is reflected in the transition matrices, which do not indicate any direct intersystem crossing channels to the T 1 state.