In this paper, we report density functional theory (DFT) studies to fully understand the coordination interactions between 1,4-disubstituted 1,2,3-triazole derivatives and the metal center of Zn(II)-porphyrins. Coordination through the most electron-rich N3 atom of the triazole heterocycle is more favorable. However, the energy difference between the N2- and N3-coordinated isomers is moderate and the less stable is likely also present in the solution. The binding of 1,4-disubstituted 1,2,3-triazole ligands to oxidized and reduced Zn(II)-porphyrins has been also investigated. Upon reduction, the binding interactions are extremely weak and the formation of the complex is not favorable anymore. In contrast, the binding energy is considerably increased upon oxidation of the Zn(II)-porphyrin moiety thus leading to more stable complexes. The calculations fully support experimental findings and explain the differences observed for the redox potentials of complexed and uncomplexed Zn(II)-porphyrin residues.

在本文中，我们报告了密度泛函理论（DFT）研究，以充分理解1,4-二取代的1,2,3-三唑衍生物与Zn(II)-卟啉金属中心之间的配位相互作用。通过三唑杂环中最富电子的N3原子进行配位是更有利的。然而，N2 和 N3 配位异构体之间的能量差异适中，溶液中也可能存在稳定性较差的异构体。还研究了 1,4-二取代 1,2,3-三唑配体与氧化和还原 Zn(II)-卟啉的结合。还原后，结合相互作用极弱，不再有利复合物的形成。相反，Zn(II)-卟啉部分氧化后结合能显着增加，从而产生更稳定的复合物。