Linear Antiferromagnetism in the Organic Free Radical 1,3-Bisdiphenylene-2-Phenyl Allyl

Specific-heat and electron and nuclear magnetic resonance data have been taken on the free radical 1,3-bisdiphenylene-2-phenyl allyl at temperatures down to 1.3°K. The electron resonance spectrum of a single crystal of this free radical has also been examined. The data indicate magnetic ordering along linear chains below 6°K with a coupling between chains at 1.73°K. Impurities are demonstrated to play a large part in the magnetic behavior. The data are compared with theoretical predictions concerning linear antiferromagnetism.