Conducting High-Spin (S = 1) Organic Diradical with Robust Stability

Triplet ground-state organic molecules are of interest with respect to several emerging technologies but usually show limited stability, especially, as thin films. We report an organic diradical, based entirely on two Blatter radicals, that possesses triplet ground state (2J/k ≈ 220 K, EST ≈ 0.4 kcal mol-1 ) and robust stability, with onset of decomposition above 264 C (TGA). Polycrystalline diradical is a good electrical conductor with conductivity comparable to the out-of-plane conductivity in highly oriented pyrolytic graphite (HOPG). The diradical is evaporated under ultra-high vacuum to form thin films, which are stable on air for at least 18 and 48 h, as demonstrated by X-ray photoelectron and electron paramagnetic resonance (EPR) spectroscopies, respectively.