The new, well-soluble and non-aggregated peripheral or non-peripheral tetra-ethyl 7-oxy-4,8-dimethylcoumarin-3-propanoate substituted magnesium (II), zinc (II) and indium (III) acetate phthalocyanines were synthesized. They were characterized by widely known spectroscopic methods such as UV-vis, IR, MALDI-TOF Mass, H-1 NMR spectroscopies and elemental analysis. Photophysical and photochemical properties were studied in N, N-dimethylformamide to determine the usability of each of these phthalocyanines as photosensitizers. The influences of the position and presence of the coumarin derivative at the phthalocyanine skeleton and metal' nature in the phthalocyanine cavity on photophysical and photochemical properties were investigated by comparing with previous analogues (magnesium, zinc, and indium phthalocyanines containing coumarin derivative with different functional groups). The spectroscopic, photophysical, photochemical data and results obtained for each of these phthalocyanines show that they may have the potential to be used as photosensitizers in photodynamic therapy. (c) 2020 Elsevier B.V. All rights reserved.