Related Experiment Video
Updated: Oct 9, 2025

Assembling Molecular Shuttles Powered by Reversibly Attached Kinesins
Published on: January 26, 2019
Ultrafast dynamics of an azobenzene-containing molecular shuttle based on a rotaxane
Matthew M Sartin1, Masahisa Osawa1, Satoshi Takeuchi1,2
1Molecular Spectroscopy Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. tahei@riken.jp.
Abstract:
An ultrafast spectroscopic study was carried out for a photoisomerizable, rotaxane-based molecular shuttle, in which photoisomerization of the azobenzene moiety of the thread-like guest drives a shuttling motion of a cyclodextrin host. Femtosecond upconversion and time-resolved absorption measurements revealed distinct S1 dynamics with time constants of 1.2 and 17 ps. Both time constants are smaller when the cyclodextrin host is absent, implying that, within the S1 state, there are mutiple barriers to the isomerization and subsequent shuttling, due to steric interference from the cyclodextrin.
Related Concept Videos
Radical Reactivity: Overview
¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
Radical Chain-Growth Polymerization: Overview
Radical Chain-Growth Polymerization: Mechanism
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
Electrophilic Addition of HX to 1,3-Butadiene: Thermodynamic vs Kinetic Control

