To treat a life‐threatening disease like cancer, photodynamic therapy (PDT) and sonodynamic therapy (SDT) methods were combined into sono‐photodynamic therapy (SPDT) as an effective therapeutic solution. Each day, the usage of phthalocyanine sensitizers increases in the therapeutic applications as they have the ability to produce more reactive oxygen species. In this context, a new diaxially silicon phthalocyanine sensitizer, containing triazole and tert‐butyl groups, was synthesized. After elucidating the structure of the complex with elemental analysis, FT‐IR, UV–Vis, MALDI–TOF MS and ¹H NMR, its photophysical, photochemical and sono‐photochemical properties were examined. When singlet oxygen generation capacity of the new synthesized silicon phthalocyanine complex was determined and compared among photochemical (PDT; Ф_Δ = 0.59 in DMSO, 0.44 in THF, 0.47 in toluene) and sonophotochemical (SPDT; Ф_Δ = 0.88 in dimethyl sulfoxide (DMSO), 0.60 in tetrahydrofuran (THF), 0.65 in toluene) methods, it can be said that the complex is a successful sono‐photosensitizer that can be used as a good SPDT agent in vitro or in vivo future studies.

This study presents the synthesis of a series of new tetra-substituted phthalocyanines bearing 3,5-bis(trifluoromethyl)phenoxy groups at non-peripheral positions. The resulting macromolecules were characterized by performing different spectroscopic methods including ¹H NMR, UV-Vis, FT-IR, and mass spectroscopy. In this study, the synergistic effect of phthalocyanines used as colorants in ink formulas with other chemicals available was probed for the first time. The synergistic effect of methyl laurate on the biological and antioxidant activities of the compounds (2–5) was investigated. Moreover, the therapeutic properties of the complexes (3, 6, and 7) were investigated using photochemical methods. Upon comparison, complex 7 (Φ_Δ = 0.42) was found to be more effective than complex 6 (Φ_Δ = 0.40) and complex 3 (Φ_Δ = 0.27) in terms of producing singlet oxygen. The results confirmed that the heavy atom effect improves the therapeutic effects.