A switchable palladium-complexed molecular shuttle and its metastable positional isomers.
We report the design, synthesis, characterization, and operation of a [2]rotaxane in which a palladium-complexed macrocycle can be translocated between 4-dimethylaminopyridine and pyridine monodentate ligand sites via reversible protonation, the metal remaining coordinated to the macrocycle throughout. The substitution pattern of the ligands and the kinetic stability of the Pd-N bond means that changing the chemical state of the thread does not automatically cause a change in the macrocycle's position in the absence of an additional input (heat and/or coordinating solvent/anion). Accordingly, under ambient conditions any of the four sets of protonated and neutral, stable, and metastable co-conformers of the [2]rotaxane can be selected, manipulated, isolated, and characterized.
Crowley
James D
JD
School of Chemistry, University of Edinburgh, The King's Buildings, West Mains Road, Edinburgh EH9 3JJ, United Kingdom.
Leigh
David A
DA
Lusby
Paul J
PJ
McBurney
Roy T
RT
Perret-Aebi
Laure-Emmanuelle
LE
Petzold
Christiane
C
Slawin
Alexandra M Z
AM
Symes
Mark D
MD