Air-Stable and Luminescent Trityls via Methoxy Modification

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Trityl luminescence, first reported in 1944, has been limited by synthetic challenges in modifying pristine trityl structures.
• Air-stable polyhalogenated trityls have previously demonstrated notable luminescent properties.

Purpose of the Study:

• To synthesize novel methoxy-substituted trityl radicals (TOMe).
• To systematically investigate the impact of methoxy groups on radical stability and luminescent properties.
• To explore a new framework for luminescent trityl compounds.

Main Methods:

• Stepwise synthesis of six air-stable methoxy-substituted trityls (TOMe).
• Characterization of their luminescent properties, including emission spectra and photoluminescence quantum yields (PLQY).
• Evaluation of radical stability influenced by methoxy group substitution.

Main Results:

• The synthesized TOMe compounds exhibit luminescence in the 588-629 nm range.
• Photoluminescence quantum yields (PLQY) ranged from 2.7% to 4.5%, which is 3-5 times higher than tris(2,4,6-trichlorophenyl)methyl radical.
• A notable PLQY of up to 61% was achieved for TOMe2c in solid films.

Conclusions:

• Methoxy substitution provides an effective strategy to enhance the luminescent properties of trityl radicals.
• The synthesized methoxy-substituted trityls demonstrate superior photoluminescence and radical stability.
• These findings offer a new and promising class of luminescent trityl frameworks for advanced applications.