Photoalignment and Surface-Relief-Grating Formation are Efficiently Combined in Low-Molecular-Weight Halogen-Bonded Complexes

Authors

  • Arri Priimagi,

    Corresponding author
    1. Chemical Resources Laboratory, Tokyo Institute of Technology, R1-12 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
    2. Department of Applied Physics, Aalto University, School of Science and Technology, P.O. Box 13500, FI-00076 Aalto, Finland
    • Chemical Resources Laboratory, Tokyo Institute of Technology, R1-12 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
    Search for more papers by this author
  • Marco Saccone,

    1. NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy
    Search for more papers by this author
  • Gabriella Cavallo,

    1. NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy
    Search for more papers by this author
  • Atsushi Shishido,

    Corresponding author
    1. Chemical Resources Laboratory, Tokyo Institute of Technology, R1-12 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
    • Chemical Resources Laboratory, Tokyo Institute of Technology, R1-12 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
    Search for more papers by this author
  • Tullio Pilati,

    1. NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy
    Search for more papers by this author
  • Pierangelo Metrangolo,

    Corresponding author
    1. NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy
    2. Center for Nano Science and Technology@Polimi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, I-20133 Milano, Italy
    3. VTT - Technical Research Centre of Finland, Tietotie 2, FIN-02044 VTT, Finland
    • NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy.
    Search for more papers by this author
  • Giuseppe Resnati

    Corresponding author
    1. NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy
    2. Center for Nano Science and Technology@Polimi, Istituto Italiano di Tecnologia, Via Pascoli 70/3, I-20133 Milano, Italy
    • NFMLab, DCMIC “Giulio Natta”, Politecnico di Milano, Via Mancinelli 7, I-20131 Milano, Italy.
    Search for more papers by this author

Abstract

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.

Ancillary