Study of Photochemical and Photophysical Properties of Indium(III) and Titanium(IV) Phthalocyanine Derivatives Containing 3,5-Di-tert-Butyl Groups

This study focuses on the design and characterization of two phthalocyanine molecules, 1,8(11),15(18),22(25)-tetra-(3,5-di-tert-butylphenoxy)phthalocyaninato indium(III)acetate (In-4) and 1,8(11),15(18),22(25)-tetra-(3,5-di-tert-butylphenoxy)phthalocyaninatooxotitanium(IV) (Ti-5). The composition of the complexes was confirmed by the methods on the basis of UV-Vis, FTIR and ¹H NMR spectroscopies as well as elemental analyse and Maldi Tof techniques. Investigating the photochemical and photophysical properties of both axial metal complexes revealed a notably high singlet oxygen quantum yield. Density functional theory (DFT) calculations are used to rationalise the relative stability and photophysical properties of these complexes. The effects of the In-4 complex on cervical cancer were assessed through mitochondrial dehydrogenase activity, which indicated an IC₅₀ at a concentration of 100 µM. Analysis of cell index data suggested the initiation of the cell death pathway, accompanied by DNA damage. Subsequent evaluation of the mitotic index was showed a decrease over time. These findings suggest the potential successful utilization of the In-4 complex in thephotodynamic therapy of cervical cancer. This novel research highlights both the PDT properties of phthalocyanines and the antiproliferative effects of the In-4 complex on HeLa cells.