Experimental and Computational Study on Photophysical Properties of Mesoionic Chalcogenones

Area of Science:

• Coordination Chemistry
• Materials Science
• Photophysics

Background:

• N-heterocyclic carbene (NHC) adducts with main group elements (NHC=E) are well-studied in coordination chemistry.
• NHC adducts with chalcogens (NHC=Ch) have been investigated, but their photophysical properties remain largely unexplored.
• Previous research focused on synthesis, coordination chemistry, and electrochemistry.

Purpose of the Study:

• To investigate the photophysical properties of mesoionic carbene adducts with sulfur and selenium.
• To explore their luminescence in both solution and solid states.
• To elucidate the luminescent mechanism using computational methods.

Main Methods:

• Experimental investigation of photophysical properties (fluorescence and phosphorescence).
• Solution and solid-state measurements.
• Time-dependent density functional theory (TD-DFT) calculations.

Main Results:

• Mesoionic carbene adducts with sulfur and selenium exhibit blue fluorescence in dichloromethane.
• Orange to red room-temperature phosphorescence observed in the solid state.
• Dual emission detected in mesoionic thiones.

Conclusions:

• Mesoionic carbene adducts with sulfur and selenium possess unique luminescent properties.
• These findings open new avenues for exploring their applications in optoelectronics.
• TD-DFT calculations provide insights into the underlying luminescent mechanisms.