The constitutes and isomer distribution of di-(potassium sulfonate)-di-phthalimidomethyl phthalocyanine zinc

Sulfonate and/or phthalimidomethyl phthalocyanine zincs are obtained by the condensation reaction of anhydrous zinc acetate and two precursors, i.e. 4-phthalimidomethyl phthalonitrile and 4-(potassium sulfonated) phthalonitrile. The ZnPcS n P m mixture was separated into 5 components according to the number of substituted sulfonate groups and each component which has the same chemical constituent consists of different regioisomers. An HPLC method in isocratic conditions was developed to exercise quality control and make quantitative analysis of the photosensitizer, di-(potassium sulfonate)-diphthalimidomethyl phthalocyanine zinc (abbreviated as ZnPcS 2 P 2 , here, S represents sulfonate group, P the phthalimidomethyl group and ZnPc the phthalocyanine zinc). Furthermore, by comparing the retention behavior of ZnPcS 2 P 2 with that of ZnPcS 2 , positional structure of isomers of ZnPcS2P2 was speculated. Reversed-phase HPLC method with TEA-phosphate buffer and DMF as eluents in gradient conditions has been proved to be a powerful tool for the separation of such complex system.