Güzel Emre
Department of Engineering Fundamental Sciences, Faculty of Technology, Sakarya University of Applied Sciences, Sakarya, 54050, Turkey.
J Fluoresc. 2025 Mar 29. doi: 10.1007/s10895-025-04281-3.
Photodynamic therapy (PDT) is a medical treatment that uses a photosensitizer molecule and a light source to induce the formation of reactive oxygen species in tissue. Phthalocyanines (Pcs) are macrocyclic photosensitizers with useful photophysical and photochemical properties in PDT applications. Motivated by these facts, this study has experimentally and theoretically investigated the suitability of 2,6-di-(tert-butyl)-4-methylphenoxy substituted zinc Pc (dt-ZnPc) in the first steps of PDT applications. Photophysical and photochemical characteristics of dt-ZnPc were measured and validated with the literature. Also, the suitability of the dt-ZnPc complex substituted with 2,6-di-(tert-butyl)-4-methylphenoxy groups for PDT applications has been supported by theoretical calculations for the first time. Density Functional Theory (DFT) and time-dependent DFT (TDDFT) calculations, incorporating both vertical excitation and adiabatic processes, were employed to elucidate the optical and photochemical mechanisms underlying singlet oxygen generation by unsubstituted metal-free and zinc Pcs and dt-ZnPc. Calculated excited state energies agreed well with experimental results, enabling the prediction of photosensitizer activity based on excited state properties and enhanced spin-orbit coupling (SOC) imparted by the metal center.
光动力疗法（PDT）是一种利用光敏剂分子和光源在组织中诱导活性氧物种形成的医学治疗方法。酞菁（Pcs）是一类大环光敏剂，在光动力疗法应用中具有有用的光物理和光化学性质。基于这些事实，本研究在光动力疗法应用的初步阶段，对2,6-二（叔丁基）-4-甲基苯氧基取代的锌酞菁（dt-ZnPc）的适用性进行了实验和理论研究。测量了dt-ZnPc的光物理和光化学特性，并与文献进行了验证。此外，首次通过理论计算支持了用2,6-二（叔丁基）-4-甲基苯氧基取代的dt-ZnPc配合物在光动力疗法应用中的适用性。采用密度泛函理论（DFT）和含时密度泛函理论（TDDFT）计算，结合垂直激发和绝热过程，阐明了未取代的无金属酞菁、锌酞菁和dt-ZnPc产生单线态氧的光学和光化学机制。计算得到的激发态能量与实验结果吻合良好，能够基于激发态性质预测光敏剂活性，并预测金属中心赋予的增强自旋-轨道耦合（SOC）。
