For the latter strategy, one can make use of the previously discussed trends. When trying to achieve higher wavelength regions, for example, it might thus be advisable to remove the electron donating methyl substituent from the chemical space and instead replace it with a group that is more important in these regions. In this specific example, the amine, hydroxyl, cyano and methoxy substituents were the most decisive for the inner and outer positions, in respective pairs. Focusing on the center, a possibly useful replacement could thus be the thiol group, since it has similar properties as the hydroxyl and shares the possibility of forming hydrogen bonds. Focusing on the outer position, a nitroso substituent may serve as another strongly electron withdrawing group similar to the cyano substituent.