A Type of Atypical AIEgen Used for One-Photon/Two-Photon Targeted Imaging in Live Cells

Aggregation-induced
emission luminogens (AIEgens) with a large
electron donor and acceptor (D–A) conjugated system have been
widely used in the development of organic light emitting diodes (OLEDs),
chemosensors, and bioimaging materials due to their excellent properties
such as high quantum yields, long emission wavelengths, controllable
luminescence lifetimes, and nonlinear optics (NLO) properties. However,
most of the AIE materials have been derived from limited classic AIE
cores such as tetraphenylethene (TPE) and tetraphenylpyrazine (TPP),
and thus, tedious syntheses or later modifications toward those AIEgens
have always been unavoidable. In this report, a type of atypical AIEgens
(designated as ASIQs) composed of large conjugated structures with
a natural electron D–A system is disclosed, which shows large
Stokes shifts, high photostabilities, excellent cell permeabilities,
low biotoxicities, and good two-photon excited capacities, making
them suitable for applications of one-photon/two-photon targeted imaging
in live cells. In short, this work offers a type of atypical AIEgens
which will possibly become an ideal platform leading to more structurally
diverse and functionally excellent AIE-based luminescent materials.