ring attached to the P is trifling (labs(7[OTf]) = 448 nm, labs(7-9-10-11[OTf]) = 3 nm). However, when the nature of the substituent is changed (Cy vs Ph vs Napht), the impact on the absorption wavelengths becomes more significant as the maximal absorption wavelengths shift from labs (8[OTf]) = 419 nm to labs (12[OTf]) = 468 nm. We have performed theoretical calculations to probe the nature of the excited states of these systems. The protocol is detailed in the SI, and goes beyond standard TD-DFT using wavefunction theories for transition energies, as cyanines are known to be challenging for this level of theory. The vertical absorption wavelength computed is 408 nm for 7 + logically blue shifted as compared to experiment (see below). More interesting is that very similar wavelengths are determined for 9 + (410 nm), 10 + (415) nm, and 11 + (404 nm), whereas significantly smaller and larger absorption wavelengths are respectively predicted for 8 + (387 nm) and 12 + (439 nm), in perfect agreement with the experiments. Fig. displays the frontier orbitals and electron density difference (EDD) plot for 7 + . Consistent with a cyanine nature, the EDD plot displays an alternation on odd/even carbon atoms that undergo large decrease/increase of electronic density upon absorption. The changes of density on the atoms not involved in the cyanine moiety are essentially negligible but for the fluorine atom attached to the central carbon atoms that acts as a secondary donor group. The LUMO is nevertheless slightly delocalized on the side phenyl rings. In Fig. , the same representation is given for 8 + and 12 + and one notes similar topologies for the EDD and MOs, which respectively slightly less and more delocalized LUMO as compared to 7 + .