Chen Z.-JLu H.-FChao IJYE-SHANE YANG2022-12-142022-12-14202200094536https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131635115&doi=10.1002%2fjccs.202200190&partnerID=40&md5=688e18658ea6e1d9f9573c78cfbc0f57https://scholars.lib.ntu.edu.tw/handle/123456789/626321We report herein a new rotation-inversion dual-motion molecular switch (1), in which a 3,3-dimethylazetidinyl (DMAZ) group is the rotator and a stiff-stilbene is the helical stator. There are two sets of nuclear magnetic resonance (NMR) signals in the DMAZ group, the H-shaped AZ protons and the planar C2-symmetrical Me protons, for probing the kinetics of the DMAZ rotation and the stiff-stilbene inversion. While the two motion modes are highly correlated in (E)-1, they are decoupled in (Z)-1. The rotation-inversion correlated motion in (E)-1 is governed by the faster inversion mode, whereas the inversion is much slower than the rotation in (Z)-1. Consequently, photochemical isomerization between (E)-1 and (Z)-1 switches not only the relative rate of the rotation versus inversion motion but also the on–off behavior of the rotation-inversion correlated motion. This work shows the cooperation of two sets of proton signals in elucidating the correlated motion in a dual-motion molecular system. © 2022 Chemical Society Located in Taipei and Wiley-VCH GmbH.molecular device; organic chemistry; spectroscopy; theoretical molecular science[SDGs]SDG3journal article10.1002/jccs.2022001902-s2.0-85131635115