A Nitronyl Nitroxide-Substituted Benzotriazinyl Tetraradical

Area of Science:

• Organic chemistry
• Materials science
• Quantum chemistry

Background:

• High-spin organic tetraradicals are crucial for advanced applications but often lack stability and processability.
• Existing tetraradicals face limitations in thermal stability and synthetic accessibility.

Purpose of the Study:

• To design and synthesize a novel, stable high-spin organic tetraradical.
• To investigate the structural, electronic, and magnetic properties of the new tetraradical.

Main Methods:

• Synthesis via palladium-catalyzed cross-coupling of a triiodo-benzotriazinyl radical derivative with a gold(I) nitronyl nitroxide-2-ide complex.
• Structural confirmation using X-ray diffraction analysis.
• Characterization of magnetic properties using SQUID magnetometry and EPR spectroscopy.
• Theoretical analysis with high-level quantum chemical calculations.

Main Results:

• Successful synthesis of a novel tetraradical combining Blatter's radical and nitronyl nitroxide moieties.
• The tetraradical exhibits good thermal stability (decomposition onset at ~150°C) and reversible redox behavior.
• Magnetic studies and quantum chemical calculations confirm a triplet ground state and a nearby excited quintet state.

Conclusions:

• The newly synthesized triazinyl-nitronylnitroxide tetraradical demonstrates unprecedented stability.
• This work represents a significant advancement in the development of stable high-spin molecular systems.
• The findings pave the way for future applications of high-spin organic materials.