Spin‐Correlated Luminescence of Mechanically Generated Radical Species

ABSTRACT A tetraarylsuccinonitrile (TASN) derivative ( 1 2 ) substituted with bulky triarylmethane groups dissociated into luminescent cyanodiarylmethyl radical 1 upon thermal or mechanical stimulation. The average dissociation yield after mechanochemical treatment was 2.6%, among the highest reported for small‐molecule TASN compounds. Ground 1 2 showed a magnetic field effect on luminescence, the first such observation from a radical emitter other than triarylmethyl radicals. This study demonstrates the universality of spin‐correlated luminescence among luminescent radicals.