ACQ-to-AIE Transformation: Tuning Molecular Packing by Regioisomerization for Two-Photon NIR Bioimaging

作者：Li, Yuanyuan; Liu, Shunjie; Ni, Huwei; Zhang, Haoke; Zhang, Hequn; Chuah, Clarence; Ma, Chao; Wong, Kam Sing; Lam, Jacky W. Y.; Kwok, Ryan T. K.^*; Qian, Jun; Lu, Xuefeng; Tang, Ben Zhong

来源：Angewandte Chemie - International Edition, 2020, 59(31): 12822-12826.

DOI：10.1002/anie.202005785

• ACQ-to-AIE transformation
• aggregation-induced emission
• cross packing
• regioisomerization
• two-photon imaging

The traditional design strategies for highly bright solid-state luminescent materials rely on weakening the intermolecular pi-pi interactions, which may limit diversity when developing new materials. Herein, we propose a strategy of tuning the molecular packing mode by regioisomerization to regulate the solid-state fluorescence. TBP-e-TPA with a molecular rotor in the end position of a planar core adopts a long-range cofacial packing mode, which in the solid state is almost non-emissive. By shifting molecular rotors to the bay position, the resultant TBP-b-TPA possesses a discrete cross packing mode, giving a quantum yield of 15.6 +/- 0.2 %. These results demonstrate the relationship between the solid-state fluorescence efficiency and the molecule's packing mode. Thanks to the good photophysical properties, TBP-b-TPA nanoparticles were used for two-photon deep brain imaging. This molecular design philosophy provides a new way of designing highly bright solid-state fluorophores.

• 单位
  复旦大学; 浙江大学