An Anthracene Based Photoswitchable Dioxo‐Tetraaza Ligand Selective for Cu II and Capable of Photochemical p K a 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 Cu II , 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 (LH 2 ), can also be used for the photoinduced release of protons in aqueous solution, as a result of photoinduced p K a modulation.