Fig. 4: Theoretical energy level diagram with the difference of electronic density associated to the transition from the ground state to S1.

Schematic of the low-lying excited states (red = triplet and blue = singlet) of p-ICz-PI, o-ICz-PI and Cz-PI at the ground and S1 excited state geometries. The electronic density differences (red is loss and green is gain in electron density upon excitation) associated with these transitions are shown on the right. Transition oscillator strengths are given alongside the calculated transition wavelength. All the energies are shown in Supplementary Tables 4, 9 and 14.