Fig. 2.

Characteristic force-extension curves of a [4]- (A) and [7]rotaxane (B) mechanically stretched at 7.5 × 10⁴ pN·s⁻¹ in DMF, showing equally spaced force peaks, each separated by 2.4 nm. Each peak corresponds to the breaking of intramolecular interactions on both sides of the ring and the maximum peak value corresponds to the rupture force. The red dotted lines are worm-like chain fits. See Supporting Information for details. Distribution of the rupture force for the pulling of the [4]- (C) and [7]rotaxane (D) in DMF at 7.5 × 10⁴ pN·s⁻¹. The most probable values were obtained by log-normal fits and peak at 101.2 ± 1.2 pN (n = 3,338) (C) and 104 ± 4.5 pN (n = 362) (D).