Supramolecular Solid-State Microlaser Constructed from Pillar[5]arene-Based Host-Guest Complex Microcrystals

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Optoelectronics

Background:

• Aggregation-caused quenching (ACQ) and other nonradiative decay pathways limit the luminescent efficiency of many organic dyes.
• Developing host-guest complexes can provide spatial confinement to mitigate these effects.
• Pillar[5]arene (P5) is a macrocyclic host with potential for encapsulating guest molecules.

Purpose of the Study:

• To synthesize and characterize a novel host-guest complex for enhanced luminescence.
• To investigate the effect of spatial confinement on the photophysical properties of a laser dye.
• To explore the potential of the resulting material for laser applications.

Main Methods:

• Single crystal X-ray diffraction to determine the host-guest complex structure.
• Photoluminescence spectroscopy to evaluate luminescent efficiency.
• Fabrication of microcrystals for laser output measurements.

Main Results:

• A 2:1 host-guest complex of pillar[5]arene (P5) and trans-4-[ p-(dimethylamino)styryl]-1-methylpyridinium iodide (DASP) was successfully synthesized.
• The P5 nanocapsule effectively isolated DASP molecules, suppressing aggregation-caused quenching and other nonradiative decay channels.
• The resulting 2P5⊃DASP microcrystals exhibited high luminescent efficiency and formed stable Fabry-Pérot microcavities, enabling laser output with high Q factor and low threshold.

Conclusions:

• The novel P5-DASP host-guest complex effectively isolates the dye, leading to significantly enhanced luminescence.
• The microcrystals act as efficient Fabry-Pérot microcavities, demonstrating potential for solid-state laser applications.
• This supramolecular strategy offers a promising route for developing high-performance luminescent materials.