Molecular motion of donor–acceptor catenanes in water

Abstract

In this article, we use ¹H NMR spectroscopy to study the spontaneous molecular motion of donor–acceptor [2]catenanes in water. Our data supports the hypothesis that conformational motion dominantly occurs through a pirouetting mechanism, which involves less exposure of hydrophobic surfaces than in a rotation mechanism. Motion is controlled by the size of the catenane rings and the arrangement of the electron-deficient and electron-rich aromatic units.