Dual-Responsive Molecular Switches Based on Dithienylethene–RuII Organometallics in Self-Assembled Monolayers Operating at Low Voltage

5 years ago

Dual-Responsive Molecular Switches Based on Dithienylethene–RuII Organometallics in Self-Assembled Monolayers Operating at Low Voltage

Lucie Norel, Yves-Marie Hervault, Xiaoyan He, Andrea Mulas, Corinne Lagrost, Stéphane Rigaut

Two carbon-rich ruthenium complexes bearing a dithienylethene (DTE) unit and a hexylthiol spacer were designed to be attached on gold surfaces. Both compounds display photochemically driven switching properties, allowing reversible conversion from open to closed forms of the DTE units upon irradiation in solution. In contrast, only the bimetallic complex undergoes an efficient electrochemical ring closure at low potential, (0.5 V vs. SCE), whereas the monometallic complex shows a simple one-electron reversible redox event. These appealing switching properties could be successfully transferred within diluted self-assembled monolayers (SAMs). Furthermore, the two immobilized organometallics exhibit fast electron-transfer kinetics. Therefore, this organometallic strategy allows us to obtain multifunctional surfaces with the possibility of combining switching events triggered by an electrochemical oxidation at low potential and by light at distinct wavelengths for a write-and-erase function, along with an access to different oxidation states. Importantly, a non-destructive electrochemical read-out is achieved at a sufficiently high scan rate that prevents any electrochemical closing. On the whole, the two surface-confined organometallic compounds exhibit appealing properties for application in molecular electronics. Self-assembled monolayers (SAMs) of RuII–DTE organometallic compounds afford multifunctional surfaces combining electro- or photoswitching at remarkably low voltage and fast nondestructive electrochemical read-out.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201701903