Spin Characteristics in Conjugated Stable Diradicals

Abstract

Spin properties are intrinsic characters of electron. Radical molecules contain unpaired electron(s), their unique chemical and physical properties make them an ideal platform for investigating spin properties in molecular system. Among them, the burgeoning interest in stable conjugated diradicals is attributed to their distinctive characteristics, notably the dynamic resonance structures between open-shell and closed-shell forms, the malleability of their spin states, and the profound influence of intermolecular spin-spin interactions. A deep understanding of the spin characteristics of unpaired electrons in stable conjugated diradicals provides guidance for the design, synthesis, and characterization of radical-based materials. In this review, we take the perspective of the unique spin delocalization, spin states, and spin-spin coupling characteristics of conjugated diradicals. We emphasize how to precisely control these spin characteristics to understand the role in the molecule and as functional radical materials.