| Autor: |
Cho HJ; Department of Chemistry, Sungkyunkwan University, 2066 Seobu-ro, Janan-gu, Suwon-si, Gyeonggi-do 16419 Republic of Korea., Kim KS; Department of Chemistry, Sungkyunkwan University, 2066 Seobu-ro, Janan-gu, Suwon-si, Gyeonggi-do 16419 Republic of Korea., Kim H; Department of Chemistry, Sungkyunkwan University, 2066 Seobu-ro, Janan-gu, Suwon-si, Gyeonggi-do 16419 Republic of Korea., Kim T; Department of Chemistry, Sungkyunkwan University, 2066 Seobu-ro, Janan-gu, Suwon-si, Gyeonggi-do 16419 Republic of Korea., Malyutin AG; Beckman Institute, California Institute of Technology, Pasadena, CA 91125, United States., Rees DC; HHMI, California Institute of Technology, Pasadena, CA 91125, United States.; Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States., Yoo BK; HHMI, California Institute of Technology, Pasadena, CA 91125, United States.; Department of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States., Song C; Department of Chemistry, Sungkyunkwan University, 2066 Seobu-ro, Janan-gu, Suwon-si, Gyeonggi-do 16419 Republic of Korea. |
| Abstrakt: |
Aggregation-induced emission (AIE) phenomena have gained intense interest over the last decades because of its importance in solid-state emission. However, the elucidation of a working mechanism is difficult owing to the limited characterization methods on solid-state molecules, further complicated if dynamic structural changes occur. Here, a series of bis-arylacylhydrazones ( BAHs ) were synthesized, for which their AIE properties are only turned on by the reversible adsorption of water molecules. We used microcrystal electron diffraction (MicroED) to determine the molecular structures of two BAHs directly from bulk powders (without attempting to grow crystals) prepared in the absence or presence of water adsorption. This study reveals the unambiguous characterization of the dependence of crystal packing on the specific cocrystallization with hydrates. The structural analysis demonstrates that water molecules form strong hydrogen bonds with three neighboring BAH-1 , resulting in the almost complete planarization and restriction of the intramolecular rotation of the molecule. MicroED plays an important role in providing a decisive clue for the reversible polymorphism changes induced by the adsorption of water molecules, regulating emissive properties. |
