Hyperbranched Polyborosiloxanes: Non‐traditional Luminescent Polymers with Red Delayed Fluorescence

• Published in: Angewandte Chemie International Edition 2023-11, Vol.62 (48), p.e202312571-n/a
• Main Authors: He, Yanyun, Feng, Weixu, Qiao, Yujie, Tian, Zhixuan, Tang, Ben Zhong, Yan, Hongxia
• Format: Article
• Language: English
• Subjects: Addition polymerization; Biocompatibility; Delayed Fluorescence; Development strategies; Electron Delocalization; Electron density; Emission analysis; Fluorescence; Light emission; Polyborosiloxanes; Polymers; Red Emission; Synergistic effect; Through-Space Interaction; Wavelengths
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202312571

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. The synergistic effect of dual heteroatom‐induced electron delocalization and through‐space O⋅⋅⋅O and O⋅⋅⋅N interactions has been used to construct non‐traditional fluorescence polymers with long emission wavelengths and fluorescence lifetimes. This has led to a hyperbranched polyborosiloxane that exhibits red emission at 640 nm and delayed fluorescence with a lifetime of 9.73 μs.