AIEgens Based on Dehydroabietic Acid Triarylamine and Tetraphenylethene: Synthesis, Luminescence Regulation, and Application in Cell Imaging

Abstract

Biomass-derived luminogens with strong emission capacity in the aggregated or solid state are in demand because of their renewability, sustainability, and biocompatibility. Herein, we synthesized aggregation-induced emission luminogens (AIEgens) based on dehydroabietic acid triarylamine (DTPA) derived from natural rosin, and their spectral properties, molecular conformation, electron distribution, and energy levels were explored to elucidate the effect and mechanism of structure regulation. The prepared AIEgens exhibited different emission wavelengths and luminescence efficiencies attributed to the conjugation degree and molecular motion. DTPA–mTPE with a meta-linkage mode exhibits blue emission with highest quantum yield among all compounds. DDPA–pTPE, formed by DTPA sharing a phenyl ring with TPE, redshifts visibly from 488 to 508 nm, attributed to the narrower excited-state energy gap. Introducing a dehydroabietic acid skeleton creates a rigid molecular conformation, and a highly twisted molecular conformation is unfavorable to stabilize the excited-state molecular conformation and reduces luminous efficiency. Finally, DTPA–pTPE, DTPA–mTPE, 2DTPA–mTPE, and DDPA–pTPE were prepared nanoparticles, which exhibited low cellular toxicity and excellent cell imaging results. This work offers new insights into the synthesis of rosin-based AIEgens, facilitating the design of naturally derived luminescent materials.