THE EFFECT OF OXYGEN ON PHTHALOCYANINE RADICALS .2. COMPARATIVE-STUDY OF 2 LITHIUM PHTHALOCYANINE POWDER DERIVATIVES BY CONTINUOUS AND PULSED ESR

A new phthalocyanine radical derivative, LiPc(CH3O)8, is extensively studied by electron spin resonance. The dynamic properties show an extremely narrowed single line due to spin exchange interactions. A drastic oxygen effect affecting linearly the linewidth (20 G/bar) is compared to that reported on LiPc (5 G/bar). In the octamethoxy derivative both static and dynamic properties are consistent with the absence of magnetic defects. Slow kinetics of molecular oxygen diffusion is observed: the reduced diffusion coefficient (7 x 10(-5) s-1) and the activation energy (0.27 eV) are similar to those obtained for LiPc powders.