Spin Frustration in Organic Radicals.

Area of Science:

• Condensed Matter Physics
• Materials Science
• Organic Chemistry

Background:

• Spin frustration arises from geometric constraints preventing simultaneous satisfaction of antiferromagnetic interactions.
• It is considered a fundamental characteristic for the emergence of quantum spin liquids (QSLs).
• Organic radical species offer versatile chemical structures for designing spin-frustrated systems.

Purpose of the Study:

• To review and summarize reported organic radical compounds exhibiting spin frustration.
• To consolidate data on magnetic exchange coupling, spin models, and lattice structures.
• To highlight the potential of organic radicals in developing novel spin-frustrated materials.

Main Methods:

• Literature review of existing studies on spin-frustrated organic radical compounds.
• Compilation and analysis of reported magnetic exchange coupling parameters.
• Summary of relevant spin models, frustration parameters, and crystallographic data.

Main Results:

• Identified various classes of organic radical compounds exhibiting spin frustration, including triradicals, TTF derivatives, [Pd(dmit)2] compounds, nitronyl nitroxides, fullerenes, PAHs, and heterocycles.
• Collected and discussed data on magnetic properties and structural characteristics.
• Highlighted the intra- and intermolecular origins of spin frustration in these systems.

Conclusions:

• Organic radical compounds are promising platforms for realizing spin frustration and exploring QSL physics.
• Systematic summarization of existing data facilitates further research and design of new materials.
• Understanding the interplay between molecular structure and magnetic interactions is crucial for controlling spin frustration.