Novel triazole substituted phthalocyanines showing high singlet oxygen quantum yields

In this study, novel triazole peripherally substituted phthalocyanine zinc(II) complexes 3(a-d) were synthesized from four different phthalonitrile derivative and characterized by FT-IR NMR, MALDI-TOF, UV–Vis methods. Aggregation-concentration relations of the compounds 3(a-d) were investigated by UV–Vis spectroscopy. Fluorescence quenching properties of the phthalocyanines 3(a-d) were studied and fluorescence quantum yields were calculated by comparative method. Photodegradation quantum yields of the compound 3(a-d) were calculated. In addition, singlet oxygen quantum yields of the compounds 3(a-d) were measured by comparative method by using 1,3-diphenylisobenzofuran (DPBF) as singlet oxygen quencher. In this work, it has been observed that the synthesized novel phthalocyanines have higher quantum yield values (the range of 0.8–0.85) compared to the Zn (II) complex of unsubstituted phthalocyanine (0.67). Especially the compound 3d substituted tolyl group has the highest singlet oxygen quantum yield (0.85) seen rarely in literature.