Instituto de Tecnología Química, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Avenida de los Naranjos s/n, 46022 Valencia, Spain.
Dpto. Química Inorgánica, ISQCH-Instituto de Síntesis Química y Catálisis Homogénea, Facultad de Ciencias, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain.
J Org Chem. 2022 Sep 2;87(17):11433-11442. doi: 10.1021/acs.joc.2c00942. Epub 2022 Aug 18.
Photosensitized thymine<>thymine (Thy<>Thy) formation and repair can be mediated by carbazole (Cbz). The former occurs from the Cbz triplet excited state via energy transfer, while the latter takes place from the singlet excited state via electron transfer. Here, fundamental insight is provided into the role of the topology and excited state multiplicity, as factors governing the balance between both processes. This has been achieved upon designing and synthesizing different isomers of trifunctional systems containing one Cbz and two Thy units covalently linked to the rigid skeleton of the natural deoxycholic acid. The results shown here prove that the Cbz photosensitized dimerization is not counterbalanced by repair when the latter, instead of operating through-space, has to proceed through-bond.
吖啶（Cbz）可介导光致敏胸腺嘧啶<>胸腺嘧啶（Thy<>Thy）形成和修复。前者通过能量转移从 Cbz 三重态激发态发生，而后者则通过电子转移从单重激发态发生。在此，通过设计和合成含有一个 Cbz 和两个 Thy 单元的三功能体系的不同异构体，提供了有关拓扑和激发态多重性作为控制这两个过程平衡的因素的基本见解，这些单元通过刚性骨架的天然去氧胆酸共价连接。这里展示的结果证明，当后者必须通过键而不是通过空间进行时，Cbz 光敏二聚化不会被修复所平衡。
