The drive to miniaturize devices has led to a variety of molecular machines inspired by their macroscopic counterparts such as molecular motors, switches, nanovehicles and tweezers. Even if the control of motion at the molecular level has been mastered by some machines, the reversible control of properties at the molecular level remains a challenge. We are interested in the design of switchable molecular tweezers to control physical or chemical properties at the molecular level via a mechanical motion. Our system is based on a substituted terpyridine ligand that can switch upon metal coordination between an open "W" shaped form and a closed "U" shaped form bringing two functional units into close proximity. The functional units are based on salen complexes with magnetic or luminescent properties depending on the metallic center.

The synthesis and reversible switching of luminescent tweezers based on Pt-salen complexes will be presented as well as the impact of intercalation on the luminescence properties. The switching of magnetic interaction via a mechanical motion in Cu-salen and Ni-salen based tweezers will also be highlighted.

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