Sulphur- and Selenium-for-Oxygen Replacement as a Strategy to Obtain Dual Type I/Type II Photosensitizers for Photodynamic Therapy

Mario Prejanò; Marta Erminia Alberto; Bruna Clara De Simone; Tiziana Marino; Marirosa Toscano; Nino Russo

doi:10.3390/molecules28073153

Sulphur- and Selenium-for-Oxygen Replacement as a Strategy to Obtain Dual Type I/Type II Photosensitizers for Photodynamic Therapy

Molecules. 2023 Apr 1;28(7):3153. doi: 10.3390/molecules28073153.

Authors

Mario Prejanò¹, Marta Erminia Alberto¹, Bruna Clara De Simone¹, Tiziana Marino¹, Marirosa Toscano¹, Nino Russo¹

Affiliation

¹ Dipartimento di Chimica e Tecnologie Chimiche, Università della Calabria, 87036 Arcavacata di Rende, CS, Italy.

Abstract

The effect on the photophysical properties of sulfur- and selenium-for-oxygen replacement in the skeleton of the oxo-4-dimethylaminonaphthalimide molecule (DMNP) has been explored at the density functional (DFT) level of theory. Structural parameters, excitation energies, singlet-triplet energy gaps (ΔE_S-T), and spin-orbit coupling constants (SOC) have been computed. The determined SOCs indicate an enhanced probability of intersystem crossing (ISC) in both the thio- and seleno-derivatives (SDMNP and SeDMNP, respectively) and, consequently, an enhancement of the singlet oxygen quantum yields. Inspection of Type I reactions reveals that the electron transfer mechanisms leading to the generation of superoxide is feasible for all the compounds, suggesting a dual Type I/Type II activity.

Keywords: PDT; TDDFT; Type I/Type II.

Grants and funding

This research received no external funding.