10.1021/ja047637t.s001 Timothy S. Keizer Timothy S. Keizer Nancy N. Sauer Nancy N. Sauer T. Mark McCleskey T. Mark McCleskey Designer Ligands for Beryllium American Chemical Society 2004 motif ligands outcompete chromotropic acid presence DHBA binding constants fluorescence OH binding polynulear species HIPA BeL 2 species beryllium 2004-08-11 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Designer_Ligands_for_Beryllium/3328957 We report the rational design of ligands that selectively bind beryllium. We selected two ligands to design Be based on binding polynulear species with a motif:  2-hydroxyisophthalic acid (HIPA) and 2,3-dihydroxybenzoic acid (DHBA). All previous work has focused on BeL or BeL<sub>2</sub> species. The HIPA and DHBA have extremely high binding constants of 17.5 and 18.4, respectively. These ligands outcompete chromotropic acid, which has one the highest binding constants for Be reported in the literature for a simple BeL species. The binding of the second Be to form the motif is so strong that polynuclear species predominates in solution down to micromolar concentrations. Both ligands show a fluorescence response in the presence of beryllium, making them promising candidates for fluorescence-based sensors. In the case of HIPA, there is a fluorescence shift, and in the case of DHBA, the presence of beryllium turns on the fluorescence by removing two OH bonds that otherwise lead to nonradiative decay. The most dramatic result is that DHBA selectively binds Be in the presence of a metal cocktail containing a 50-fold excess of Al, Fe, Cr, Cu, Zn, Cd, and Pb. <i>This is the first time that such selectivity for beryllium has </i><i>been demonstrated.</i>