A Solution‐Processable Single‐Component Molecular Antiferromagnet

Developing solution‐processable molecular materials with long‐range magnetic order remains a formidable challenge for molecular electronic and spintronic applications. Herein, we present a diethoxybenzene‐fused neutral‐radical gold dithiolene complex, Au(4OEt) , as a solution‐processable single‐component molecular antiferromagnet. Owing to its ethoxy substituents, Au(4OEt) adopts a two‐dimensional (2D) herringbone arrangement and exhibits semiconducting behavior characteristic of a Mott insulator. Magnetic susceptibility, solid‐state 1 H NMR, and magnetic torque measurements reveal the emergence of long‐range canted antiferromagnetic (CAF) order below approximately 8 K. Combined with transfer‐integral calculations and magnetic analyses, these results suggest that constructing a 2D herringbone arrangement of neutral‐radical molecules with dominant 2D exchange interactions (| J 2 | > | J 1 |) is important for stabilizing the magnetic ordering. Leveraging its solubility, we successfully fabricated solution‐processed crystalline thin films that retain the CAF phase. Moreover, the crystalline thin film functions as an ambipolar field‐effect transistor (FET). This work thus provides a remarkable example of a solution‐processable single‐component molecular antiferromagnet exhibiting ambipolar FET characteristics, and establishes a structural design strategy for realizing magnetically ordered crystalline thin films toward future antiferromagnetic devices.