Photochemical Isomerization and Topochemical Polymerization of the Programmed Asymmetric Amphiphiles

Abstract

For the advancement in multi-stimuli responsive optical devices, we report the elaborate molecular engineering of the dual photo-functionalized amphiphile (abbreviated as AZ1DA) containing both a photo-isomerizable azobenzene and a photo-polymerizable diacetylene. To achieve the efficient photochemical reactions in thin solid films, the self-assembly of AZ1DA molecules into the ordered phases should be precisely controlled and efficiently utilized. First, the remote-controllable light shutter is successfully demonstrated based on the reversible trans-cis photo-isomerization of azobenzene group in the smectic A mesophase. Second, the self-organized monoclinic crystal phase allows us to validate the photo-polymerization of diacetylene moiety for the photo-patterned thin films and the thermo-responsible color switches. From the demonstrations of optically tunable thin films, it is realized that the construction of strong relationships between chemical structures, molecular packing structures and physical properties of the programmed molecules is the core research for the development of smart and multifunctional soft materials.

From Smart Denpols to Remote‐Controllable Actuators: Hierarchical Superstructures of Azobenzene‐Based Polynorbornenes

“…From careful analysis, it is found that AZ 3 P denpol in the highly ordered LC phase maintains a layered hierarchical superstructure containing the smectic F (SmF)‐like lateral azobenzene packing with 2D dimensions of a = 0.77 nm and b = 0.55 nm. The layer thickness reduced slightly to L = 5.96 nm due to the higher molecular tilt and the close molecular packing . The phase assignments and molecular packing models of AZ 3 P are illustrated in Figure b.…”

Photoinduced Reversible Bending and Guest Molecule Release of Azobenzene-Containing Polydiacetylene Nanotubes

“…By combining the properties of azobenzenes and PDAs, it has been possible to design azobenzene-containing PDA systems 54–62 and some of these systems displayed photo-induced colorimetric changes 61,62 . We also reported that an azobenzene-containing diacetylene monomer forms a crystalline, blue-colored PDA upon irradiation with 254 nm light 62 .…”

Photochemically and Thermally Programmed Optical Multi‐States from a Single Diacetylene‐Functionalized Cyanostilbene Luminogen

“…However, this chemical change does not make notable variation in molecular packing structure (Figure S15, Supporting Information). [39,40] As a result, topochemically polymerized DACSM (Poly-DACSM) has almost identical molecular packing structure with SA-DACSM and exhibits a blue color and an extremely quenched emission due to the absorption of polydiacetylene at 𝜆 max = 628 nm and Förster resonance energy transfer (FRET) effect from cyanostilbene to polydiacetylene, respectively. [41][42][43] Additionally, Poly-DACSM exhibits a thermochromic behavior due to the presence of polydiacetylene.…”