Immobilizing Triphenylamine with Photoredox Inert Sr<sup>2+</sup> Forming <scp>Sr‐MOF</scp> with Controlled Electron Migration for Photocatalytic Oxidation of Thiols to Disulfides
Ying‐Xia Wang, Fang Zheng, Dong‐Xia Song, Bao‐Yue Niu, Lu‐Qian Deng, Xian‐Ming Zhang
Abstract
Comprehensive Summary The 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), (Me 2 NH 2 )[Sr(TCBPA)]·DMA·3H 2 O ( 1 ), by direct self‐assembly of tris(4′‐carboxybiphenyl)amine (H 3 TCBPA) and photoredox inert strontium ion (Sr 2+ ). DFT calculations revealed that the valence band maximum (VBM) and the conduction band minimum (CBM) are mainly located on TCBPA 3– , successfully inhibiting the undesirable electron migration to metal nodes. Experimental results indicated that 1 displays superior performance than homogeneous H 3 TCBPA, which may result from the abundant π···π and C—H···π interactions between the well‐arranged TCBPA 3– and the build‐in electric field between the anionic framework and the Me 2 NH 2 + . 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.