New peripherally and non-peripherally tetra-substituted metal-free, magnesium(II) and zinc(II) phthalocyanine derivatives fused chalcone units: Design, synthesis, spectroscopic characterization, photochemistry and photophysics

[Display omitted] •The syntheses of new chalcone substituted phthalocyanines were reported.•These phthalocyanines were characterized by spectroscopic methods and elemental analysis.•Photophysical and photochemical features of new phthalocyanines were studied in DMF.•The new zinc (II) chalcone-phthalocyanines can be used as suitable photosensitizers in PDT. Chalcone containing new peripherally and non-peripherally tetra-substituted metal-free and metallophthalocyanine derivatives were designed and synthesized (Schemes 1 and 2). The structures of chalcone-phthalocyanines were characterized by a combination of common spectroscopic techniques such as LC–MS/MS (for new phthalonitrile derivative 3a), ground state electronic absorption spectra (for all new phthalocyanines), 1H NMR spectroscopy (for all new compounds), 13C NMR spectroscopy (for new phthalonitrile and metal-free phthalocyanine derivatives), Fourier transform infrared (FT–IR with ATR sampling accessory) (for all new compounds) and MALDI–TOF mass spectral data (for all new phthalocyanines and new phthalonitrile derivative 3b) as well as elemental analysis. In addition, the effects of the presence of different kinds of metal ions [magnesium(II) or zinc (II)] in the phthalocyanine core and the effects of the introduction of (3,4-dimethoxyphenyl)-3-oxoprop-1-en-1-yl)phenoxy units at both peripheral and non-peripheral positions of the phthalocyanine skeleton on photophysical and photochemical properties of the new substituted magnesium(II) and zinc(II) phthalocyanines have also been examined in DMF. The obtained results were compared with each other and with unsubstituted magnesium(II) and zinc(II) phthalocyanines. All newly synthesized phthalocyanines are soluble in common organic solvents as well as no type of aggregation was observed in these solvents. Moreover; the chalcone fused magnesium(II) and zinc(II) phthalocyanines also showed excellent fluorescence properties. Specifically, the new non-peripheral zinc(II) and magnesium(II) chalcone-phthalocyanines have the remarkable potential to be used as Type II photosensitizers for the treatment of cancer in PDT owing to their good singlet oxygen and appropriate photodegradation quantum yields. Since chalcones and their derivatives show a broad range of biological and pharmaceutical activities, these products are promising candidates for various applications, particularly as photosensitizers for photodynamic therapy in combination with fluorescence imagin