Photoalignment and surface-relief-grating formation are efficiently combined in low-molecular-weight halogen-bonded complexes.
It is demonstrated that halogen bonding can be used to construct low-molecular-weight supramolecular complexes with unique light-responsive properties. In particular, halogen bonding drives the formation of a photoresponsive liquid-crystalline complex between a non-mesogenic halogen bond-donor molecule incorporating an azo group, and a non-mesogenic alkoxystilbazole moiety, acting as a halogen bond-acceptor. Upon irradiation with polarized light, the complex exhibits a high degree of photoinduced anisotropy (order parameter of molecular alignment > 0.5). Moreover, efficient photoinduced surface-relief-grating (SRG) formation occurs upon irradiation with a light interference pattern, with a surface-modulation depth 2.4 times the initial film thickness. This is the first report on a halogen-bonded photoresponsive low-molecular-weight complex, which furthermore combines a high degree of photoalignment and extremely efficient SRG formation in a unique way. This study highlights the potential of halogen bonding as a new tool for the rational design of high-performance photoresponsive suprastructures.
Chemical Resources Laboratory, Tokyo Institute of Technology, R1-12 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan. arri.priimagi@aalto.fi
Arri
A
Priimagi
Marco
M
Saccone
Gabriella
G
Cavallo
Atsushi
A
Shishido
Tullio
T
Pilati
Pierangelo
P
Metrangolo
Giuseppe
G
Resnati
D006219:Halogens / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D050866:Liquid Crystals / Q000737:chemistry* / Q000528:radiation effects*; D008422:Materials Testing; D008970:Molecular Weight; D012031:Refractometry / Q000379:methods*; D013499:Surface Properties
D006219:Halogens