Visualization of the slide-ring effect: a study on movable cross-linking points using mechanochromism.

To evaluate the 'slide-ring' effect in a rotaxane cross-linked network, we incorporated mechanochromophores into static and rotaxane cross-linking points and compared the mechanochromisms exhibited by the obtained polymers. This novel strategy reveals a molecular-level phenomenon with visible color changes as well as enabling quantitative electron paramagnetic resonance measurements.