Selective electrochemical magnesium and calcium sensors based on non-macrocyclic nitrogen-containing ferrocene ligands

Abstract

Ferrocene derivatives 1, 2a, 2b and 5 act as electrochemical sensors of Mg2+ and Ca2+ ions in acetonitrile solution in concentrations as low as 10 mol%: a new redox peak appears in the cyclic voltammogram, anodically shifted by 160–360 mV, with no interference from a large excess of several other metal salts; the single crystal X-ray structure of ligand 5 is reported.