Intermolecular Halogen Interaction-Induced Efficient Room-Temperature Phosphorescence in Isomer Crystals: A...

Area of Science:

• Materials Science
• Solid-State Chemistry
• Computational Chemistry

Background:

• Room-temperature phosphorescence (RTP) is crucial for advanced optical applications.
• Intermolecular halogen bonds are increasingly used to tune RTP properties.
• Understanding the precise role of halogen bonds in RTP efficiency is essential.

Purpose of the Study:

• To investigate the impact of intermolecular halogen bonds on RTP properties in isomer crystals.
• To elucidate the relationship between halogen bond contribution and phosphorescence quantum efficiency (Φp).
• To provide theoretical guidance for designing high-Φp RTP materials.

Main Methods:

• Utilized quantum mechanics/molecular mechanics (QM/MM) with the ONIOM model.
• Employed the general Amber force field and restrained electrostatic potential charge.
• Analyzed three isomer crystal systems to assess halogen bond contributions.

Main Results:

• A direct correlation was found between intermolecular halogen bond contribution to the Hirshfeld surface and Φp.
• Isomer crystals with greater halogen bond contributions exhibited higher Φp.
• Intermolecular halogen bonds significantly reduce the nonradiative transition rate (k_nr), boosting Φp.

Conclusions:

• Intermolecular halogen bonds are key determinants of Φp in RTP crystals.
• Optimizing halogen bond strength and contribution is a viable strategy to enhance RTP.
• This study offers a theoretical framework for developing efficient RTP materials.