Magnetic Multistability in an Anion‐Radical Pimer

다국어 초록 (Multilingual Abstract)

Radical pimers are the simplest and most important models for studying charge‐transfer processes and provide deep insight into π‐stacked organic materials. Notably, radical pimer systems with magnetic bi‐ or multistability may have important applications in switchable materials, thermal sensors, and information‐storage media. However, no such systems have been reported. Herein, we describe a new pimer consisting of neutral N‐(n‐propyl) benzene triimide ([BTI‐3C]) and its anionic radical ([BTI‐3C]−.) that exhibits rare magnetic multistability. The crystalline pimer was readily synthesized by reduction of BTI‐3C with cobaltocene (CoCp2). The transition occurred with a thermal hysteresis loop that was 27 K wide in the range of 170–220 K, accompanied by a smaller loop with a width of 25 K at 220–242 K. The magnetic multistability was attributed to slippage of the π‐stacked BTI structures and entropy‐driven conformational isomerization of the side propyl chains in the crystalline state during temperature variation.
Slipping into place: An anion‐radical pimer consisting of neutral N‐(n‐propyl) benzene triimide and its anionic‐radical counterpart has been developed that shows rare magnetic multistability. The magnetic multistability was attributed to slippage of the π‐stacked units and conformational isomerization of the propyl side chains during temperature variation (see picture).