Luminescence Properties of Compressed Tetraphenylethene: The Role of Intermolecular Interactions.
Mechanochromic materials with aggregation-induced enhanced emission (AIEE) characteristic have been intensively expanded in the past few years. In general, intermolecular interactions invariably alter photophysical processes, while their role in the luminescence properties of these AIEE-active molecules is difficult to fully recognize because the pressurized samples possess amorphous nature in many cases. We now report the high-pressure studies on a prototype AIEE-active molecule, tetraphenylethene, using diamond anvil cell technique with associated spectroscopic measurements. An unusual pressure-dependent color, intensity, and lifetime change in tetraphenylethene has been detected by steady-state photoluminescence and time-resolved emission decay measurements. The flexible role of the aromatic C-H···π and C-H···C contacts in structural recovery, conformational modification, and emission efficiency modulation upon compression is demonstrated through structure and infrared analysis.
†State Key Laboratory of Superhard Materials, Jilin University, Qianjin Street 2699, Changchun 130012, China.
Hongsheng
H
Yuan
†State Key Laboratory of Superhard Materials, Jilin University, Qianjin Street 2699, Changchun 130012, China.
Kai
K
Wang
‡Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhang Heng Road, Shanghai 201203, China.
Ke
K
Yang
†State Key Laboratory of Superhard Materials, Jilin University, Qianjin Street 2699, Changchun 130012, China.
Bingbing
B
Liu
†State Key Laboratory of Superhard Materials, Jilin University, Qianjin Street 2699, Changchun 130012, China.
Bo
B
Zou
aggregation-induced enhanced emission (AIEE); conformational analysis; fluorescence; high pressure; intermolecular interactions; ring-opening reaction