Room-Temperature Phosphorescence from Encapsulated Pyrene Induced by Xenon

Area of Science:

• Photochemistry
• Supramolecular Chemistry
• Materials Science

Background:

• Phosphorescence from aromatic molecules like pyrene at room temperature is typically hindered by poor intersystem crossing and oxygen quenching.
• Overcoming these limitations is crucial for developing new luminescent materials and probes.

Purpose of the Study:

• To achieve and characterize room-temperature phosphorescence from pyrene.
• To investigate the role of supramolecular encapsulation and heavy atom effects in promoting phosphorescence.

Main Methods:

• Utilizing a water-soluble supramolecular host (octa acid, OA) to encapsulate pyrene.
• Introducing xenon gas to induce the heavy atom effect.
• Employing computational modeling and Nuclear Magnetic Resonance (NMR) studies for structural and mechanistic insights.

Main Results:

• Successfully recorded phosphorescence from pyrene at room temperature within the OA capsule.
• Xenon incorporation significantly enhanced intersystem crossing (S1 to T1) and radiative decay (T1 to S0) via the heavy atom effect.
• The OA host effectively suppressed oxygen quenching, preserving the phosphorescent emission.

Conclusions:

• A three-component supramolecular assembly of OA, pyrene, and xenon enables efficient room-temperature phosphorescence in pyrene.
• This strategy overcomes common photophysical limitations, opening avenues for utilizing pyrene phosphorescence in various applications.
• Computational and NMR data confirm the co-encapsulation of pyrene and xenon within the OA host.