416 Redox-Active "Wurster-Type" Receptors for Cations, Anions and Complete Salts

Friday, November 6, 2009: 9:50 AM
Rio Grande (Camino Real Hotel)
John W. Sibert , Department of Chemistry, The University of Texas at Dallas, Richardson, TX

Inspired by the famed 150 year old compound commonly referred to as Wurster's reagent (N,N,N',N'-tetramethyl-para-phenylenediamine), Wurster's crowns are a class of macrocycles distinguished by the incorporation of the electrochemically active phenylenediamine moiety within the macrocyclic framework.  Importantly, the phenylenediamine subunit promotes strong interactions between the redox center and a variety of guests using either a linking nitrogen atom(s) or the electron-rich pi face.  The possible combinations of phenylenediamine isomers (ortho, meta and para), tunable redox centers, donor atoms and overall molecular topology endow these compounds with a rich coordination chemistry and promise in applications that include redox switches, sensors, transport agents, catalysis and molecular magnetism.  Recently, we have extended the Wurster-based platform to include receptors capable of capturing anions with concomitant changes in their electrochemical properties.  Further, hybrid hosts with discrete anion and cation binding domains display cooperative binding behavior with characteristic redox activity.  We wish to report here on the synthesis, properties and coordination chemistry of representative members of Wurster-type receptors with particular emphasis on the relationships between ligand architecture, electrochemical properties and coordination chemistry.