Sensitive and Selective Detection of Cesium via Fluorescence Quenching

Herein we report a robust and easy method for detecting cesium metal ion (Cs+) in partially aqueous solutions using the fluorescence quenching of 2,4-bis[4-(N,N-dihydroxyethylamino) phenyl]squaraine. This squaraine dye was found to be both highly sensitive (low limits of detection) and selective (limited response to other metals) for cesium ion detection. The detection is likely based on the metal complexing to the dihydroxyethanolamine moieties, which disrupts the donor-acceptor-donor architecture and leads to efficient quenching

Highly Efficient Non-Covalent Energy Transfer in All-Organic Macrocycles

The use of aromatic organic macrocycles as supramolecular hosts for non-covalent energy transfer is reported herein. These macrocycles lead to stronger binding and more efficient energy transfer compared to commercially available γ-cyclodextrin. This energy transfer was particularly efficient for the highly toxic benzo[a]pyrene with a fluorescent BODIPY acceptor, with up to a 5-fold increase in the fluorophore emission observed

Water oxidation by mononuclear ruthenium complexes with TPA-based ligands

The synthesis, characterization, and water oxidation activity of mononuclear ruthenium complexes with tris(2-pyridylmethyl)amine (TPA), tris(6-methyl-2-pyridylmethyl)amine (Me 3TPA), and a new pentadentate ligand N,N-bis(2-pyridinylmethyl)-2,2′-bipyridine-6-methanamine (DPA-Bpy) have been described. The electrochemical properties of these mononuclear Ru complexes have been investigated by both experimental and computational methods. Using Ce IV as oxidant, stoichiometric oxidation of water by [Ru(TPA)(H 2O) 2] 2+ was observed, while Ru(Me 3TPA)(H 2O) 2] 2+ has much less activity for water oxidation. Compared to [Ru(TPA)(H 2O) 2] 2+ and [Ru(Me 3TPA)(H 2O) 2] 2+, [Ru(DPA-Bpy)(H 2O)] 2+ exhibited 20 times higher activity for water oxidation. This study demonstrates a new type of ligand scaffold to support water oxidation by mononuclear Ru complexes. © 2011 American Chemical Society