Ligand-Isomerization Strategy Achieves Exceptional Wide-Range Zero-Thermal-Quenching Phosphorescence in Copper-Iodide...

Area of Science:

• Materials Science
• Photophysics
• Inorganic Chemistry

Background:

• Copper(I)-halide clusters are promising for optoelectronics due to unique photophysical properties.
• Thermal quenching (TQ) significantly limits the performance and application of these luminescent materials.
• Developing strategies to mitigate TQ is crucial for advancing cluster-based emitters.

Purpose of the Study:

• To design and synthesize novel copper(I)-iodide cluster materials with enhanced anti-thermal quenching (anti-TQ) performance.
• To investigate the structure-property relationships governing thermal stability in these luminescent materials.
• To explore the potential applications of these advanced materials in optoelectronics and anticounterfeiting.

Main Methods:

• Isomeric ligand engineering using ortho- and para-substituted bis(imidazole) benzene ligands.
• Synthesis of two distinct cluster-based coordination polymers (CP1 and CP2).
• Characterization through structural and photophysical analyses, including temperature-dependent emission studies.

Main Results:

• Two coordination polymers, CP1 and CP2, exhibiting cluster-centered phosphorescence were successfully synthesized.
• CP2 demonstrated remarkable zero-thermal-quenching (ZTQ) behavior, retaining emission intensity up to 500 K.
• CP1 exhibited conventional TQ, with a 72% intensity loss at 500 K, highlighting the effectiveness of the ligand design.
• The enhanced stability of CP2 is attributed to its rigid crystalline structure, confined cluster core, and ordered π-π stacking, suppressing nonradiative decay.

Conclusions:

• Molecular design, specifically isomeric ligand engineering, can dramatically improve the anti-TQ performance of copper(I)-iodide cluster materials.
• The rigid crystalline architecture of CP2 is key to achieving ZTQ behavior by minimizing nonradiative pathways.
• These materials show significant potential for applications in light-emitting diodes and anticounterfeiting technologies.
• This study provides fundamental insights into structure-property relationships and offers a new design paradigm for thermally stable luminescent materials.