Reversible Switching of the Emission of Diphenyldibenzofulvenes by Thermal and Mechanical Stimuli

The thermochromic and mechanochromic fluorescence of diphenyldibenzofulvenes is investigated. Emission is boosted and blue-shifted upon crystallization. Yellow emissive crystals of the material transform to green fluorescent crystals upon heating before melting. Reversible switching of the emission color and efficiency are achieved by repeated amorphization and crystallization of dye molecules by a pure thermal process or grinding–heating cycles.

• NS
  National Science Foundation
• UG
  University Grants Committee
• MO
  Ministry of Science and Technology of the People's Republic of China
• RG
  Research Grants Council, University Grants Committee
• ZU
  Zhejiang University
• FR
  Fundamental Research Funds for the Central Universities