Tuning the mechanical flexibility of organic molecular crystal by polymorphism for flexible optical waveguide
- Crystalline molecular materials are usually brittle and are prone to break into pieces upon external mechanical force. This fragility poses challenges for their application in next-generation technologies, including sensors, synthetic tissues, and advanced opto-electronics. The recent discovery of mechanical flexibility in single crystals of molecular materials has solved this issue and enable the design of smart flexible device technologies. Plastic crystals can be deformed permanently. This behavior is based on anisotropic molecular arrangements and the existence of facile slip planes which allow a permanent motion within the lattice. In contrast, elastic crystals can be deformed, but regain the original structure when the force is removed. This phenomenon is related to energetically isotropic molecular packing. Here we report 4-bromo-6-[(6-chlorolpyridin-2-ylimino)methyl]phenol (BCMPMP) as a promising candidate for future waveguide technologies. It turns out that BCMPMP has twoCrystalline molecular materials are usually brittle and are prone to break into pieces upon external mechanical force. This fragility poses challenges for their application in next-generation technologies, including sensors, synthetic tissues, and advanced opto-electronics. The recent discovery of mechanical flexibility in single crystals of molecular materials has solved this issue and enable the design of smart flexible device technologies. Plastic crystals can be deformed permanently. This behavior is based on anisotropic molecular arrangements and the existence of facile slip planes which allow a permanent motion within the lattice. In contrast, elastic crystals can be deformed, but regain the original structure when the force is removed. This phenomenon is related to energetically isotropic molecular packing. Here we report 4-bromo-6-[(6-chlorolpyridin-2-ylimino)methyl]phenol (BCMPMP) as a promising candidate for future waveguide technologies. It turns out that BCMPMP has two different polymorphs with distinct optical and mechanical properties. Form I crystallizes in the orthorhombic space group Pca21 and shows brittle behavior. This structure exhibit very weak emission at 605 nm (λex = 425 nm) together with a low fluorescence quantum yield (Φ = 0.4 %). On the other hand, form II (monoclinic space group P21/c) has a large plastic regime and a bright emission at 585 nm (λex = 425 nm; Φ = 8.7 %). Based on its improved mechanical and optical properties, form II was explored as a bendable optical waveguide. Light was successfully propagated through a straight-shaped and mechanically deformed BCMPMP crystal. Depending on the light source, active or passive waveguiding could be achieved. So BCMPMP can also be used as a flexible wavelength filter.…
Autor*innen: | Torvid FeilerORCiD |
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Koautor*innen: | Biswajit Bhattacharya, Adam Michalchuk, S.-Y. Rhim, V. Schröder, E. List-Kratochvil, Franziska Emmerling |
Dokumenttyp: | Posterpräsentation |
Veröffentlichungsform: | Präsentation |
Sprache: | Englisch |
Jahr der Erstveröffentlichung: | 2021 |
Organisationseinheit der BAM: | 6 Materialchemie |
6 Materialchemie / 6.0 Abteilungsleitung und andere | |
6 Materialchemie / 6.3 Strukturanalytik | |
DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |
Freie Schlagwörter: | Flexible crystals; Polymorphism; Waveguide |
Themenfelder/Aktivitätsfelder der BAM: | Material |
Material / Materialdesign | |
Veranstaltung: | International School of Crystallography in Erice |
Veranstaltungsort: | Online meeting |
Beginndatum der Veranstaltung: | 30.05.2021 |
Enddatum der Veranstaltung: | 04.06.2021 |
Verfügbarkeit des Dokuments: | Datei im Netzwerk der BAM verfügbar ("Closed Access") |
Datum der Freischaltung: | 06.12.2021 |
Referierte Publikation: | Nein |