Organometallic turnstiles: acid and base locking and unlocking

Area of Science:

• Organometallic Chemistry
• Supramolecular Chemistry
• Molecular Machines

Background:

• Development of molecular machines relies on controllable switching mechanisms.
• Organometallic complexes offer tunable properties for constructing dynamic molecular systems.

Purpose of the Study:

• To design and characterize a symmetrical organometallic Pt(II) based molecular turnstile.
• To investigate the reversible switching behavior of the molecular turnstile between distinct states.

Main Methods:

• Synthesis of a Pt(II) based molecular turnstile with benzonitrile coordinating sites.
• Utilizing palladium(II) ions and para-dimethylaminopyridine (DMAP) as effectors for switching.
• Employing competitive metal complexes and acid-base chemistry to control the turnstile's state.

Main Results:

• The molecular turnstile exhibits reversible switching between two open states and one closed state.
• Palladium(II) complexation locks the rotor, achieving a closed state.
• Addition of DMAP unlocks the system to a second open state, while PdCl2(CH3CN)2 or MsOH addition re-induces the closed state.

Conclusions:

• The developed Pt(II) molecular turnstile demonstrates efficient and reversible control over molecular motion.
• The system's switching is modulated by metal coordination and competitive ligand displacement.
• This work contributes to the advancement of responsive molecular machines.