Here, we present a new family of light-responsive, fluorinated supramolecular liquid crystals (LCs) showing efficient and reversible light-induced LC-to-isotropic phase transitions. Our materials design is based on fluorinated azobenzenes, where the fluorination serves to strengthen the noncovalent interaction with bond-accepting stilbazole molecules, and increase the lifetime of the cis-form of the azobenzene units. The halogen-bonded LCs were characterized by means of X-ray diffraction, hot-stage polarized optical microscopy, and differential scanning calorimetry. Simultaneous analysis of light-induced changes in birefringence, absorption, and optical scattering allowed us to estimate that <4% of the mesogenic units in the cis-form suffices to trigger the full LC-to-isotropic phase transition. We also report a light-induced and reversible crystal-to-isotropic phase transition, which has not been previously observed in supramolecular complexes. In addition to fundamental understanding of light-responsive supramolecular complexes, we foresee this study to be important in the development of bistable photonic devices and supramolecular actuators.
|Numero di pagine||8|
|Rivista||Chemistry of Materials|
|Stato di pubblicazione||Published - 2016|
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Materials Chemistry
Saccone, M., Terraneo, G., Saccone, M., Poutanen, M., Fernandez-Palacio, F., Siiskonen, A., Metrangolo, P., Resnati, G., Ikkala, O., & Priimagi, A. (2016). Efficient light-induced phase transitions in halogen-bonded liquid crystals. Chemistry of Materials, 28, 8314-8321.