Publication 679

New. J. Chem., 35, 709 - 715, 2011 DOI: 10.1039/C0NJ00638F
Electrochemically active phenylenediamine probes for transition metal cation detection

Laboratoire de Chimie Analytique et d’Electrochimie, Département de Chimie, Faculté des Sciences de Tunis, Université El-Manar, 2092 Tunis El-Manar, Tunisia - Laboratoire Interfaces et Systèmes Electrochimiques, UPR 15, Université Pierre et Marie Curie, Paris 6, 75005 Paris, France - Laboratoire d’Electrochimie Moléculaire, UMR CNRS 7591, Université Paris Diderot, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France - Laboratoire «Pasteur» UMR CNRS 8640, Ecole Normale Supérieure, Université Pierre et Marie Curie - Paris 6, 24 Rue Lhomond, 75231 Paris cedex 05, France.

A novel family of tetraalkyl-p-phenylenediamine (TAPD)-based ligands has been efficiently prepared by reductive amination of heterocyclic aldehydes. The redox properties of these electrochemical active ligands change dramatically upon complexation of the transition metal cations Zn²⁺, Ni²⁺ and Cd²⁺ leading to large oxidation potential shifts of up to 950 mV depending on the nature of the ligand. Complexes with a metal to ligand ratio of 1 :2 were formed and ¹¹³Cd NMR revealed an octahedral coordination sphere of the metal. All pyridyl derivatives show a distinct chemoselectivity (Zn²⁺ > Cd²⁺ > Ni²⁺). The thiophenyl containing derivatives display a particularly high selectivity for zinc cations (Zn²⁺ » Ni²⁺, Cd²⁺).