Fluorinated phenylpyridine iridium (III) complex based on metal–organic framework as highly efficient heterogeneous photocatalysts for cross-dehydrogenative coupling reactions

Photocatalytic reactions are promising strategies for converting solar energy into chemical energy. In this work, a MOF-based composite UiO-67-IrF with Ir complex and an electron-withdrawing group (trifluoromethyl group) is prepared and used as a photocatalyst for cross-dehydrogenation coupling reactions. For comparison, UiO-67-Ir without trifluoromethyl group and their pristine MOF UiO-67-bpy were also obtained. Both Ir-bearing composites (UiO-67-IrF and UiO-67-Ir) have crystalline and porous structure and high specific surface area (> 762 m2 g−1) and can effectively utilize visible light for cross-dehydrogenative coupling reactions. Notably, UiO-67-IrF with trifluoromethyl group has a lower specific surface area, but owns higher photocatalytic performance (yields about 82–89%) than its counterpart UiO-67-Ir, due to its better light absorption and charge separation under visible-light exposure.