摘要
Photochemical reactions have an important place in photodynamic treatments. A good use of this therapeutic method requires a good mastery of the mechanisms of the reactions involved. Therefore, we have explored in this work the photosensitization mechanism of an organometallic complex of azopyridine <em>δ</em>-OsCl<sub>2</sub>(Azpy)<sub>2</sub> through a calculation with the method of Time Dependent Density Functional Theory TDDFT. First, we evaluated the effect of polar and non-polar solvents on the triplet and singlet excited states of this complex. Then secondly, we highlighted the photosensitization mechanism to understand how the complex acts over the diseased cells. These investigations have shown that the <em>δ</em>-OsCl<sub>2</sub>(Azpy)<sub>2</sub> complex is likely to develop photodynamic activity according to two mechanisms: on one hand, it can generate damage to DNA bases or target tissues indirectly through the production of singlet oxygen in water and in DMSO. On the second hand, through the production of the anionic superoxide radical <img src="Edit_a1e628d6-dcd2-41c6-bf3c-7e3cad491857.png" alt="" />in water can act directly or indirectly on these substrates. In addition, polar solvents are assumed to better carry out the photochemical reactions of this azopyridine complex of osmium.
Photochemical reactions have an important place in photodynamic treatments. A good use of this therapeutic method requires a good mastery of the mechanisms of the reactions involved. Therefore, we have explored in this work the photosensitization mechanism of an organometallic complex of azopyridine <em>δ</em>-OsCl<sub>2</sub>(Azpy)<sub>2</sub> through a calculation with the method of Time Dependent Density Functional Theory TDDFT. First, we evaluated the effect of polar and non-polar solvents on the triplet and singlet excited states of this complex. Then secondly, we highlighted the photosensitization mechanism to understand how the complex acts over the diseased cells. These investigations have shown that the <em>δ</em>-OsCl<sub>2</sub>(Azpy)<sub>2</sub> complex is likely to develop photodynamic activity according to two mechanisms: on one hand, it can generate damage to DNA bases or target tissues indirectly through the production of singlet oxygen in water and in DMSO. On the second hand, through the production of the anionic superoxide radical <img src="Edit_a1e628d6-dcd2-41c6-bf3c-7e3cad491857.png" alt="" />in water can act directly or indirectly on these substrates. In addition, polar solvents are assumed to better carry out the photochemical reactions of this azopyridine complex of osmium.
