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

Abstract

AbstractNon‐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.