Selective and Efficient Removal of Mercury from Aqueous Media with the Highly Flexible Arms of a BioMOF

Abstract A robust and water‐stable metal–organic framework (MOF), featuring hexagonal channels decorated with methionine residues ( 1 ), selectively captures toxic species such as CH 3 Hg + and Hg 2+ from water. 1 exhibits the largest Hg 2+ uptake capacity ever reported for a MOF, decreasing the [Hg 2+ ] and [CH 3 Hg + ] concentrations in potable water from highly hazardous 10 ppm to the much safer values of 6 and 27 ppb, respectively. Just like with biological systems, the high‐performance metal capture also involves a molecular recognition process. Both CH 3 Hg + and Hg 2+ are efficiently immobilized by specific conformations adopted by the flexible thioether “claws” decorating the pores of 1 . This leads to very stable structural conformations reminiscent of those responsible for the biological activity of the enzyme mercury reductase (MR).