Azobenzene-based difunctional halogen-bond donor: towards the engineering of photoresponsive co-crystals.
Halogen bonding is emerging as a powerful non-covalent interaction in the context of supramolecular photoresponsive materials design, particularly due to its high directionality. In order to obtain further insight into the solid-state features of halogen-bonded photoactive molecules, three halogen-bonded co-crystals containing an azobenzene-based difunctional halogen-bond donor molecule, (E)-bis(4-iodo-2,3,5,6-tetrafluorophenyl)diazene, C12F8I2N2, have been synthesized and structurally characterized by single-crystal X-ray diffraction. The crystal structure of the non-iodinated homologue (E)-bis(2,3,5,6-tetrafluorophenyl)diazene, C12H2F8N2, is also reported. It is demonstrated that the studied halogen-bond donor molecule is a reliable tecton for assembling halogen-bonded co-crystals with potential photoresponsive behaviour. The azo group is not involved in any specific intermolecular interactions in any of the co-crystals studied, which is an interesting feature in the context of enhanced photoisomerization behaviour and photoactive properties of the material systems.
NFMLab-DCMIC `Giulio Natta', Politecnico di Milano, Via L. Mancinelli 7, IT-20131 Milano, Italy.
Marco
M
Saccone
NFMLab-DCMIC `Giulio Natta', Politecnico di Milano, Via L. Mancinelli 7, IT-20131 Milano, Italy.
Giancarlo
G
Terraneo
NFMLab-DCMIC `Giulio Natta', Politecnico di Milano, Via L. Mancinelli 7, IT-20131 Milano, Italy.
Tullio
T
Pilati
NFMLab-DCMIC `Giulio Natta', Politecnico di Milano, Via L. Mancinelli 7, IT-20131 Milano, Italy.
Gabriella
G
Cavallo
Department of Applied Physics, Aalto University, PO Box 13500, FI-00076 Aalto, Finland.
Arri
A
Priimagi
NFMLab-DCMIC `Giulio Natta', Politecnico di Milano, Via L. Mancinelli 7, IT-20131 Milano, Italy.
Pierangelo
P
Metrangolo
NFMLab-DCMIC `Giulio Natta', Politecnico di Milano, Via L. Mancinelli 7, IT-20131 Milano, Italy.
Giuseppe
G
Resnati
halogen-bonded co-crystals; photoisomerization; supramolecular photoresponsive materials design