Photocatalysts Built In A Snap

With help from cobalt, chemists have integrated light-harnessing metal catalysts into a porous recyclable polymer (J. Am. Chem. Soc., DOI: 10.1021/ja109166b). The advance could cut down on contamination and waste disposal costs for industrial-scale chemistry. Metal complexes containing ruthenium or iridium mediate a variety of light-driven reactions. But researchers would like more-streamlined ways of recovering and reusing the catalysts after their jobs are done. To that end, Wenbin Lin and coworkers at the University of North Carolina, Chapel Hill, fused ruthenium and iridium complexes to polymers by modifying the metal’s ligands with alkynes and then using a cobalt-mediated reaction that snaps alkynes together in the form of a benzene ring. The resulting porous cross-linked materials are stable in air, don’t decompose or leach in solvent, and use light from an ordinary fluorescent lamp to drive three different reactions. Filtration is all it takes to recover the polymers, which work equally well after being recycled up to four times, the team says.