Lanthanide cerium(III) complex with deep-red emission beyond 700 nm

Area of Science:

• Materials Science
• Inorganic Chemistry
• Photochemistry

Background:

• Luminescent cerium(III) compounds are crucial for phosphors, photocatalysis, and electroluminescence.
• Existing cerium(III) emitters primarily cover ultraviolet to yellow regions due to the 5d energy level.
• Orange to deep-red emissions from cerium(III) compounds remain underdeveloped.

Purpose of the Study:

• To develop novel molecular cerium(III) complexes with red to deep-red emission.
• To explore the use of S-coordinating dithiobiuret ligands for long-wavelength cerium(III) emitters.
• To investigate the influence of steric hindrance on complex structure and emission properties.

Main Methods:

• Synthesis of molecular cerium(III) complexes utilizing S-coordinating dithiobiuret ligands.
• Characterization of photoluminescence properties, including emission maxima and quantum efficiency.
• Investigation of structural changes (mononuclear vs. dinuclear) influenced by steric hindrance in solution.

Main Results:

• Achieved red to deep-red emission, with the longest emission maximum at 725 nm.
• Obtained a photoluminescence quantum efficiency of 31% for the developed complexes.
• Demonstrated that tuning steric hindrance leads to distinct mononuclear and dinuclear cerium(III) complexes with varied emission colors and interconversion behaviors.

Conclusions:

• S-coordinating ligands show significant potential for creating deep-red cerium(III) emitters.
• The study reveals interesting coordination chemistry of molecular cerium(III) complexes.
• This work expands the scope of cerium(III) emitters into the challenging long-wavelength region.