Configurable photochromism of an unsymmetrical dithienylethene derivative by Cu2+ ions or water

• A molecular switch with gated photochromic properties was developed.
• Its photochromic properties triggered by Cu2+ ions and water were extensively studied.
• The mechanism was additionally investigated by theoretical simulations.

We describe a gated photochromic behavior of an unsymmetrical dithienylethene derivative, which is intrinsically inert to photoisomerization in organic solvents and which is activated by addition of Cu2+ ions or water. The mechanism behind the gated photochromic property is interpreted by theoretical simulations, suggesting that the energy levels of frontier molecular orbitals are altered by the interaction of the Schiff base moiety with Cu2+ ions or water molecules. Potential applications of such gated photochromic materials have been exemplified not only by the reversible interchange between the photoactive and photoinactive states triggered by Cu2+ ions and EDTA, but also by the construction of a keypad with sequence-dependent input signals at the molecular level.

A molecular switch with gated photochromic properties is successfully developed, which is intrinsically inert to photoisomerization in organic solvents and which is activated by addition of Cu2+ ions or water. The mechanism behind the gated photochromic property is investigated by theoretical stimulations. This gated photochromic behavior brings up the construction of a molecular keypad with sequence-dependent input signals.Figure optionsDownload as PowerPoint slide