“Electrical” Behavior of Photochromic Compounds

ABSTRACT

Dithienylethylene unit have been incorporated in a molecular wire. Incorporated in a Self Assembled Monolayer and tested by Scanning Tunnelling Microscopy, the molecule has been shown to have a blinking contrast. Redox properties of model compounds have been explored in order to explain this feature: all molecules can be oxidized and the resulting radical cations may undergo ring closure or opening depending on its substituents.

Keywords:

• dithienylethylene
• electrochemistry
• photochromism, switch molecular electronics, scanning tunneling microscopy

Acknowledgments

We gratefully acknowledge Prof. I. Gallardo, Universitat Autònoma de Barcelona, for electrochemical instrumentation, Mrs C. Viala for recording the NMR spectra. We also thank the “Ministerio de Educación, Cultura y Deporte” of Spain for the award of a postdoctoral grant (G.G.), the MENRST for fellowships (C.H., N.B.), and CNRS for a grant (AC-Nano, POEM)