Studies on Phthalocyanine Type Compounds (Part XI)

Solvent Treatment of Cobalt Phthalocyanine and Its Effect on the Crystal Transf ormation

Abstract

The crystal change of cobalt phthalocyanine (Co-PC) in the presence of an organic solvent was studied to clarify the catalytic mechanism of Co-PC. β-Type Co-PC, which can be transformed into α type by the high-pressure hydrogen treatment, was not converted in the presence of an organic solvent up to the three 300-minute treatments. α-Type Co-PC, on the other hand, was converted into β immediately after the treatment with a solvent.
The reaction converted benzene, which was used as the solvent for the Co-PC treatment, into cyclohexane, cyclohexene, cyclohexadiene, etc. Benzene hardly reacted in the absence of Co-PC under the same condition of the solvent treatment. β-Type Co-PC may also be transformed into α type even in an organic solvent under high-pressure hydrogen. However, the transformed α-type Co-PC could be converted rapidly to β type as a results of the reaction with solvent. Co-PC as a hydrogen carrier forms a hydrogen-transfer cycle.