Comprehensive SummaryThe photocatalytic oxidative coupling of thiols is one of the most popular methods to synthesize the disulfides. Triphenylamine and its derivatives (TPAs) are promising for the above reaction, but suffer from the easy polymerization and difficult separation. To overcome these obstacles while controlling the photogenerated electrons transfer directly to target substrates, herein, we constructed one TPA‐based metal‐organic framework (MOF), (Me2NH2)[Sr(TCBPA)]·DMA·3H2O (1), by direct self‐assembly of tris(4′‐carboxybiphenyl)amine (H3TCBPA) and photoredox inert strontium ion (Sr2+). DFT calculations revealed that the valence band maximum (VBM) and the conduction band minimum (CBM) are mainly located on TCBPA3–, successfully inhibiting the undesirable electron migration to metal nodes. Experimental results indicated that 1 displays superior performance than homogeneous H3TCBPA, which may result from the abundant π···π and C—H···π interactions between the well‐arranged TCBPA3– and the build‐in electric field between the anionic framework and the Me2NH2+. This work highlights that immobilizing TPAs into MOFs is one promising approach to designing heterogeneous photocatalysts for the synthesis of disulfides by oxidative coupling of thiols.
综合摘要 硫醇的光催化氧化偶联是合成二硫化物最常用的方法之一。三苯胺及其衍生物(TPAs)有望用于上述反应,但存在易聚合和难分离的问题。为了克服这些障碍,同时控制光生电子直接转移到目标底物,我们在本文中通过三(4′-羧基联苯)胺(H3TCBPA)和光氧化惰性锶离子(Sr2+)的直接自组装,构建了一种基于 TPA 的金属有机框架(MOF)--(Me2NH2)[Sr(TCBPA)]-DMA-3H2O (1)。DFT 计算表明,价带最大值(VBM)和导带最小值(CBM)主要位于 TCBPA3-,从而成功抑制了电子向金属节点的不良迁移。实验结果表明,1 的性能优于均相 H3TCBPA,这可能是由于排列良好的 TCBPA3- 之间存在丰富的 π---π 和 C-H---π 相互作用,以及阴离子框架与 Me2NH2+ 之间存在内建电场。这项工作突出表明,将 TPA 固定到 MOFs 中是设计异质光催化剂的一种可行方法,可通过硫醇的氧化偶联合成二硫化物。