A novel class of star-shaped multi-azobenzene photoswitches comprising individual photochromes connected to a central trisubstituted 1,3,5-benzene core is reported. Along with UV-Vis absorption spectroscopy, high performance liquid chromatography and electrochemical measurements, Ion Mobility Mass Spectrometry was used for the first time for the successful characterization of the switching of multi-photochromic compounds, revealing the occurrence of a large molecular shape change in rigid star-shaped azobenzene derivatives. Reverse switching inside the mass spectrometer was also observed, highlighting the importance of controlled instrumental parameters.
This collaboration between the groups of Paolo Samori (University of Strasbourg), Marcel Mayor (University of Basel), Michal Valášek (Karlsruhe Institute of Nanotechnology), Jérôme Cornil (CMN – UMONS) and Pascal Gerbaux (S²MOS – UMONS) led to the publication of a manuscript in JACS.
Agostino Galanti, Jasmin Santoro, Rajesh Mannancherry, Quentin Duez, Valentin Diez-Cabanes, Michal Valášek, Julien De Winter, Jérôme Cornil, Pascal Gerbaux, Marcel Mayor, and Paolo Samorì. A new class of rigid multi(azobenzene) switches featuring electronic decoupling: unravelling the isomerization in individual photochromes. J. Am. Chem. Soc., Just Accepted Manuscript. https://pubs.acs.org/doi/10.1021/jacs.9b02544