Compared to the HOMO/LUMO levels of DiKTa (-6.20/-2.23 eV) and DDiKTa (-6.04/-2.34) the HOMO of DDiKTa-A is significantly destabilized while the LUMO is effectively unchanged (-5.39/-2.24 eV). The resulting energy gap (DE) of 3.15 eV is smaller than those of DiKTa (3.97 eV) and DDiKTa (3.70 eV). As a result of the amine, there is considerable conformational flexibility in DDiKTa-A, reflected in the differences in geometry between the ground and singlet excited state (RMSD value of 0.2757, Figure ), which will likely lead to a broad emission similar to that observed for DiDOBNA-N. The energies of the low-lying singlet and triplet excited states were calculated at the SCS-ADC(2)/cc-pVDZ level (Figure ). The difference density plots reveal the expected alternating pattern of increasing and decreasing electron density in the excited states as compared to the ground state, reflective of states of SRCT character. The plots also show that the electron density is delocalized across both DiKTa moieties and the bridging nitrogen atom.