T. Barth et al., SOLID-STATE INTERACTIONS IN RADICALS - CRYSTAL-STRUCTURES OF ALPHA-10-PHENYL-5(10H)-PHENAZINL AND BETA-10-PHENYL-5(10H)-PHENAZINYL, Journal of the Chemical Society, Chemical Communications, (21), 1993, pp. 1626-1628
Crystallization of 10-phenyl-5(10H)-phenazinyl affords two modificatio
ns in which the radicals are arranged in a chain pattern along the a-a
xis (alpha) or in radical pairs along the c-axis (beta) giving rise to
considerable spin pairing.