Dinuclear Copper(II) Complexes Exhibiting Reversible Photochromism

We present here the design and preparation of several discrete coordination complexes exhibiting two Cu(II) ions separated by a dithienylcyclopentene as a photoswitchable spacer, proposed as models of molecular √SWAP quantum gates. These models use the two Cu(II) ions as realizations of qubits and the spacer as a light switch intended to trigger the gate by reversibly undergoing a ring closing isomerization. For this, a dicarboxylate species with a central diarylethene, H 2 L1, has been used, together with bipyridine or phenantroline as capping ligands. Also, a new dinucleating ligand containing the photoactive moiety between two tridentate coordinating pockets, H 4 L2, has been designed and prepared for the same purpose. The four complexes have been characterized by single‐crystal X‐ray diffraction. Three of them exhibit reversible photoswitching in solution.