Synthesis and molecular structure of a lithium complex of the phthalocyanine radical

Abstract

Controlled potential electrolysis of the dilithium salt of phthalocyanine, Li₂(pc^2–), at 0.15 V vs. saturated calomel electrode in acetonitrile gave a lithium complex of the phthalocyanine radical, the crystal structure of which shows that it contains a unit cell with four nearly planar Li(pc˙^–) molecules of S₄ symmetry, stacked metal-over-metal with an Li–Li spacing of 3.245(2)Å, and staggered by 38.7(3)°; its effective magnetic moment decreased from the room temperature value of 1.3 µ_B to 1.0 µ_B at 150 K, but upon further cooling it increased to approach the free-spin value.