Crystals of trans- and cis-isomers of a fluorinated azobenzene derivative have been prepared and characterized by single-crystal X-ray diffraction. The presence of F atoms on the aromatic core of the azobenzene increases the lifetime of the metastable cis-isomer, allowing single crystals of the cis-azobenzene to be grown. Structural analysis on the cis-azobenzene, complemented with density functional theory calculations, highlights the active role of the halogen-bond contact (N...I synthon) in promoting the stabilization of the cis-isomer. The presence of a long aliphatic chain on the azobenzene unit induces a phase segregation that stabilizes the molecular arrangement for both the trans- and cis-isomers. Due to the rarity of cis-azobenzene crystal structures in the literature, our paper makes a step towards understanding the role of non-covalent interactions in driving the packing of metastable azobenzene isomers. This is expected to be important in the future rational design of solid-state, photoresponsive materials based on halogen bonding. We show by single-crystal X-ray diffraction studies and computational analysis that halogen bonding can stabilize a metastable cis-azobenzene derivative in the solid state.
|Numero di pagine||7|
|Rivista||ACTA CRYSTALLOGRAPHICA. SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS|
|Stato di pubblicazione||Published - 2017|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Metals and Alloys
- Materials Chemistry
Saccone, M., Terraneo, G., Saccone, M., Fernandez-Palacio, F., Siiskonen, A., Metrangolo, P., Resnati, G., & Priimagi, A. (2017). Halogen bonding stabilizes a cis-azobenzene derivative in the solid state: A crystallographic study. ACTA CRYSTALLOGRAPHICA. SECTION B, STRUCTURAL SCIENCE, CRYSTAL ENGINEERING AND MATERIALS, 73, 227-233.