title: Coupled nanomechanical motions: metal-ion-effected, pH-modulated, simultaneous extension/contraction motions of double-domain helical/linear molecular strands.
abstract: A new class of shape-enforced synthetic polyheterocyclic molecular strands, containing both a helical and a linear domain, has been designed and synthesized. On reaction with Pb(II), under the effect of cation binding to the coordination subunits, the helical section unfolds into a linear shape in the complex and the linear domain folds into a helical ligand wrapped around the bound cations. Such double-domain ligand strands are thus able to undergo a combined unfolding-folding interconversion on binding and release of metal cations. These changes can be modulated through coupling to a competing ligand that reversibly binds and releases metal cations, when respectively unprotonated and protonated, on effecting alternate pH changes. The resulting process thus performs nanomechanical extension/contraction molecular motions of a linear motor type, which is fueled by acid-base neutralization.
authors.affiliation: Laboratoire de Chimie Supramoléculaire, Institut de Science et d'Ingénierie Supramoléculaires, Université de Strasbourg , 8 Allée Gaspard Monge, Strasbourg, 67000, France.
authors.forename: Adrian-Mihail
authors.initials: AM
authors.lastname: Stadler
authors.forename: Jean-Marie P
authors.initials: JM
authors.lastname: Lehn