Low-temperature synthesis of phthalocyanine and its metal complexes

Conditions for synthesizing unsubstituted phthalocyanine and its metal complexes from phthalonitrile at low temperatures (0–50°C) are optimized. Phthalocyanine and phthalocyaninates are produced under these conditions using activated Rieke metals, metals on inert substrate, sources of “soluble” metals in the form of unstable metal complexes, zeolites, solid-phase electrosynthesis of phthalonitrile, and UV irradiation. The use of pyrophoric metals is found to be the most efficient due to a large number of defects in their structure favoring the initial stage of phthalonitrile cyclization on a metal matrix. The suggested mechanism of formation of phthalocyanine macrocycle assumes participation of metal agglomerates occurring in activated metals.