Cross-linked Polymers with Exceptionally High Ru(bipy)32+ Loadings for Efficient Heterogeneous Photocatalysis

Phosphorescent cross-linked polymers 1 and 2 were synthesized via oxidative homo coupling reactions of tetra(ethynyl) derivatives of Ru(bpy)(3)(2+) (with the alkynyl groups located at 4,4'- or 5,5'- positions of two substituted bipyridines). These cross-linked polymer particles contain exceptionally high Ru(bpy)(3)(2+) loadings and serve as highly efficient and reusable heterogeneous photocatalysts for a range of organic transformations, presumably owing to the ability of the Ru(bpy)(3)(2+) moieties in the polymer network to transport triplet excited states to particle surfaces to initiate the organic reactions. This work illustrates the potential of developing photocatalytic cross-linked polymers from photoactive molecular building blocks for solar energy utilization.