Rational guest selection: a general principle for stabilizing multi-component luminescent materials

Area of Science:

• Materials Science
• Photochemistry
• Nanotechnology

Background:

• Multi-component luminescent materials often suffer from organic guest photodegradation.
• Conventional host-centric designs struggle to prevent guest molecule instability.
• Photodegradation limits the practical applications of advanced luminescent materials.

Purpose of the Study:

• Introduce a new strategy: "rational guest selection" for designing photostable luminescent materials.
• Prioritize intrinsic molecular photostability of emissive guests alongside emission color.
• Validate this principle using a Europium-based metal-organic framework (Eu-P6MOF).

Main Methods:

• Constructed the first metal-organic framework (MOF) from europium ions and pillar[6]arene (Eu-P6MOF).
• Co-encapsulated emissive organic dyes (Coumarin 6 and Coumarin 1) to achieve white-light emission.
• Applied "rational guest selection" by replacing unstable Coumarin 1 with a photostable perylene dye.

Main Results:

• Initial composite showed emission shift due to Coumarin 1 degradation under illumination.
• Replacing Coumarin 1 with perylene dye resulted in a stable white-light-emitting composite.
• Demonstrated the approach's generality in ethanol and highlighted MOF pore-induced stabilization of guests.

Conclusions:

• "Rational guest selection" provides a universal blueprint for durable multi-component functional materials.
• Intrinsic guest photostability is a critical design criterion for long-lasting luminescent materials.
• MOF pore environments enhance guest photostability by restricting molecular motion.