Colorimetric detection of copper ions in sub-micromolar concentrations using a triarylamine-linked resin bead.

The triarylamine derivative ETPA reacts with Cu(2+) to give deeply colored, stable radical cations in acetonitrile solution. ETPA was immobilized on to a tentagel resin bead which was then used for the fabrication of a simple device capable of the colorimetric detection of submicromolar concentrations of Cu(2+) ions in water. The naked eye detection limit reported here for Cu(2+) is one of the lowest ever reported for small molecule sensors.

Cu(II) mediated generation and spectroscopic study of the tris(4-anisyl)amine radical cation and dication. Unusually shielded chemical shifts in the dication.

The reaction of tris(4-anisyl)amine (TAA) with Cu(2+) ion leading to formation of the TAA radical cation and dication is described. Spectroscopic studies confirm the formation of the radical cation and dication. (1)H and (13)C NMR spectral studies reveal interesting structural features of the dication.