Direct observation of excited state conversion in solid state from a TICT-Type mechanochromic luminogen

Jianai Chen, Sijie Tan, Yue Yu, Shitong Zhang, Weijun Li, Qingbao Song, Yujie Dong, Cheng Zhang, Wai Yeung Wong

Research output: Journal article publicationJournal articleAcademic researchpeer-review

9 Citations (Scopus)


A coplanar donor-acceptor (D-A) structure in single crystal is directly observed for TICT-Type DPA-PYZ, which corresponds to a coplanar localized excited (LE) state. The conversion between coplanar LE and twisted intramolecular charge transfer (TICT) excited state in the solid state can be achieved through the change of the D-A twist angle between ~0° and ~30° during grinding, heating and solvent fumigation processes. This twist angle change between donor and acceptor was proved by the Raman, FT-IR spectroscopy and X-ray crystallographic analysis as well as theoretical calculation. This research provides the clear evidence for the conversion between coplanar LE and TICT excited states of D-A molecules in solid state and contributes much to the deep understanding of stimulus-response behavior of fluorescent D-A molecular solids from the viewpoint of excited state control.

Original languageEnglish
Article number118179
JournalJournal of Luminescence
Publication statusPublished - Sept 2021


  • Coplanar D-A structure
  • Excited state conversion
  • Mechanochromism
  • Solid-state luminescence
  • TICT
  • Triphenylamine

ASJC Scopus subject areas

  • Biophysics
  • Atomic and Molecular Physics, and Optics
  • General Chemistry
  • Biochemistry
  • Condensed Matter Physics


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