Bisazo Tröger base analogs are claw-looking molecules that carry two identical but independent photoswitching groups. These bisazo compounds, like dual switches, can be at EE, EZ, and ZZ photoisomerization states while the ∧-shape void of Tröger base scaffold may also introduce an additional possibility of stereoisomerism by holding the photoisomerizable groups in endo or exo positions. To date, the exact molecular geometries of the isomerizable analogs of Tröger's base have not been elaborated. Owing to the special features and potential applications of these molecules, herein their photoisomerization is probed. The gleaned data from 15N isotope labeling and a variety of spectroscopic, spectrophotometric, crystallographic, and computational techniques have revealed the structure of the studied photoisomers and suggested their use in the design of molecular pull and push mechanisms, light driven actuators, and artificial muscles.
Bibliographical noteFunding Information:
This article is dedicated to Associate Professor Ahmad Reza Moosavi-Zare for his invaluable comments and great companionship. Professor Barbara Messerle and Dr Yuling Wang are thanked for the provided isotope enriched reagents and access to Raman spectrometer, respectively. This work was supported by the Australian Government [ IPRS-2014004 ], and Macquarie University [ HDR43010477 , and PGRF2016R2-1672525 ].
- Azo compound
- Molecular machine
- Tröger base