An investigation into the mechanism of the phthalonitrile route to copper phthalocyanines using differential scanning calorimetry

Abstract

The thermal behaviour of the reaction of phthalonitrile with a range of copper compounds has been investigated using differential scanning calorimetry with product analysis by infrared spectroscopy. Reaction with copper metal to give copper phthalocyanine (1) is exothermic and requires the presence of air or a small amount of a copper(II) salt. Reaction with copper(II) chloride takes place smoothly either in an air or a nitrogen atmosphere to give a copper monochlorophthalocyanine (2). Reaction with copper(I) chloride is air-sensitive and gives a mixture of compounds (1) and (2). A general mechanism for this industrially important series of reactions is proposed to account for the results of the thermoanalytical investigation.