A Stable Triplet‐Ground‐State Conjugated Diradical Based on a Diindenopyrazine Skeleton

Abstract

High‐spin conjugated radicals have great potential in magnetic materials and organic spintronics. However, to obtain high‐spin conjugated radicals is still quite challenging due to their poor stability. Herein, we report the successful synthesis and isolation of a stable triplet conjugated diradical, 10,12‐diaryldiindeno[1,2‐b :2',1'‐e ]pyrazine (m‐DIP). With the m‐xylylene analogue skeleton containing electron‐deficient sp2‐nitrogen atoms, m‐DIP displays significant aromatic character within pyrazine ring and its spin density mainly delocalizes on the meta‐pyrazine unit, making it a triplet ground state conjugated diradical. Our work provides an effective "spin density tuning" strategy for stable high‐spin conjugated radicals.