Version 1
: Received: 26 October 2021 / Approved: 27 October 2021 / Online: 27 October 2021 (12:37:04 CEST)
Version 2
: Received: 17 January 2022 / Approved: 18 January 2022 / Online: 18 January 2022 (10:27:57 CET)
Frangville, P.; Kumar, S.; Gelbcke, M.; Van Hecke, K.; Meyer, F. Stimuli Responsive Materials Supported by Orthogonal Hydrogen and Halogen Bonding or I···Alkene Interaction. Molecules2021, 26, 7586.
Frangville, P.; Kumar, S.; Gelbcke, M.; Van Hecke, K.; Meyer, F. Stimuli Responsive Materials Supported by Orthogonal Hydrogen and Halogen Bonding or I···Alkene Interaction. Molecules 2021, 26, 7586.
Frangville, P.; Kumar, S.; Gelbcke, M.; Van Hecke, K.; Meyer, F. Stimuli Responsive Materials Supported by Orthogonal Hydrogen and Halogen Bonding or I···Alkene Interaction. Molecules2021, 26, 7586.
Frangville, P.; Kumar, S.; Gelbcke, M.; Van Hecke, K.; Meyer, F. Stimuli Responsive Materials Supported by Orthogonal Hydrogen and Halogen Bonding or I···Alkene Interaction. Molecules 2021, 26, 7586.
Abstract
Smart materials represent an elegant class of (macro)-molecules endowed with the ability to react to chemical/physical changes in the environment. Herein, we prepared new photo responsive azobenzenes possessing halogen bond donor groups. The X-ray structures of two molecules highlight supramolecular organizations governed by unusual noncovalent bonds. In azo dye I-azo-NO2, the nitro group is engaged in orthogonal H···O···I halogen and hydrogen bonding, linking the units in parallel undulating chains. As concern parent I-azo-NH-MMA, a non-centrosymmetric pattern is formed due to a very rare I···π interaction involving the alkene group supplemented by hydrogen bonds. The Cambridge Structural Database contains only four structures with the same I···CH2=C contact. For all compounds, a 19F NMR spectroscopic analysis confirms the formation of halogen bonds in solution through a recognition process with chloride anion, and the reversible photo-responsiveness is demonstrated upon exposing a solution to UV light irradiation. Finally, intermediate I-azo-NO2 also shows a pronounced color change due to pH variation. These azobenzenes are thereby attractive building blocks to design multi-stimuli responsive materials for highly functional devices.
Chemistry and Materials Science, Organic Chemistry
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.