An Anthracene Based Photoswitchable Dioxo‐Tetraaza Ligand Selective for CuII and Capable of Photochemical pKa Modulation

Two anthracene fragments were added to a linear dioxotetramine ligand in order to exploit a [4πs+4πs] photocycloaddition reaction and obtain a photoswitchable selective receptor for CuII, whose cavity (and binding abilities) can be closed on command. Moreover, it was demonstrated that this new ligand, N,N′-bis{2-[(anthracen-9-ylmethyl)amino]ethyl}malonamide (LH2), can also be used for the photoinduced release of protons in aqueous solution, as a result of photoinduced pKa modulation.