| Affiliation: | 1. Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology, Shaanxi Key Laboratory of Macromolecular Science and Technology, Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710129 China These authors contributed equally to this work.;2. Key Laboratory of Special Functional and Smart Polymer Materials of Ministry of Industry and Information Technology, Shaanxi Key Laboratory of Macromolecular Science and Technology, Xi'an Key Laboratory of Hybrid Luminescent Materials and Photonic Device, School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, Xi'an, 710129 China;3. Shenzhen Institute of Aggregate Science and Technology, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, 518172 China |
| Abstract: | Non-traditional fluorescent polymers have attracted significant attention for their excellent biocompatibility and diverse applications. However, designing and preparing non-traditional fluorescent polymers that simultaneously possess long emission wavelengths and long fluorescence lifetime remains challenging. In this study, a series of novel hyperbranched polyborosiloxanes (P1–P4) were synthesized. As the electron density increases on the monomer diol, the optimal emission wavelengths of the P1–P4 polymers gradually red-shift to 510, 570, 575, and 640 nm, respectively. In particular, P4 not only exhibits red emission but also demonstrates delayed fluorescence with a lifetime of 9.73 μs and the lowest critical cluster concentration (1.76 mg/mL). The experimental results and theoretical calculations revealed that the synergistic effect of dual heteroatom-induced electron delocalization and through-space O⋅⋅⋅O and O⋅⋅⋅N interaction was the key factor contributing to the red-light emission with delayed fluorescence. Additionally, these polymers showed excellent potential in dual-information encryption. This study provides a universal design strategy for the development of unconventional fluorescent polymers with both delayed fluorescence and long-wavelength emission. |
