The determination of the energy of the lowest triplet excited state (E_T1) for metalloporphyrin photosensitizers, a key parameter for rationalizing energy transfer processes in metalloporphyrins, facilitates a better understanding and optimization of their functionality. In this study, a strategy was proposed for determining the E_T1 values in metalloporphyrin systems by analyzing the temperature dependence of the oxygen quenching rate constant using time-resolved spectroscopy, with Platinum(II) octaethylporphyrin (PtOEP) and Palladium(II) octaethylporphyrin (PdOEP) as representative examples. Through a thermal equilibrium approximation of the excited triplet state (T₁) and the excited state of oxygen, a theoretical model was introduced in which the oxygen quenching rate exhibits a nonlinear dependence on temperature, enabling the determination of E_T1 values. Additionally, the validity of this approach was demonstrated through excitation spectra of metalloporphyrins. Our work provides an effective pathway and offers new insights into the energy-loss mechanisms involved in related photoconversion processes.

确定金属卟啉光敏剂最低三重激发态（E_T1）的能量是合理化金属卟啉中能量转移过程的关键参数，这有助于更好地理解和优化它们的功能。在这项研究中，提出了一种通过分析氧气淬灭速率常数的温度依赖性来确定金属卟啉系统中的E_T1值的策略，并使用铂(II)八乙基卟啉（PtOEP）和钯(II)八乙基卟啉（PdOEP）作为代表性例子。通过热平衡近似激发三重态（T₁）和氧气激发态，引入了一个理论模型，在该模型中氧气淬灭速率表现出非线性的温度依赖性，从而能够确定E_T1值。此外，还通过金属卟啉的激发光谱验证了这种方法的有效性。我们的工作提供了一条有效的途径，并为相关光电转换过程中的能量损失机制提供了新的见解。

@https://doi.org/10.1021/jacs.9b06458