Emission Tuning of Nonconventional Luminescent Materials via Cluster Engineering

Abstract Nonconventional Luminescent Materials (NLMs) with distinctive optical properties are garnering significant attention. A key challenge in their practical application lies in precisely controlling their emission behavior, particularly achieving excitation wavelength‐independent emission, which is paramount for accurate chemical sensing. In this study, NLMs (Y1, Y2, Y3, and Y4) are synthesized via a click reaction, and it is found that excitation wavelength‐dependent emission correlates with molecular cluster formation. Rigid NLMs (Y1, Y2) exhibit excitation‐independent emission in dilute solutions with nanoscale clusters but become excitation‐dependent at higher concentrations due to larger cluster formation. Flexible NLMs (Y3 and Y4) always show excitation‐dependent emission, indicating a tendency for larger cluster formation. While these NLMs exhibit high photoluminescence quantum yields (PLQYs) in dilute solutions (0.1 mg mL −1 ) up to 38.0%, they suffer from significant aggregation‐caused quenching (ACQ) in the solid state (as low as 0.5%). These findings provide insights into NLM luminescence mechanisms and offer a new approach for tuning their optical properties. With excellent optical properties, facile synthesis, and biocompatibility, these NLMs hold promise for bioimaging and other applications.