Ferrocene–Triazole–Pyrene Triads as Multichannel Heteroditopic Recognition Receptors for Anions, Cations and Ion Pairs

A number of functionalized ferrocene–triazole–pyrene triads, available from 1,1′-bis­(azido)­ferrocene by initial upper arm regioselective formation, through a copper-catalyzed click reaction, and subsequent nitrogen-containing bottom arm formation, through the remaining nitrogen functionality, have been designed, prepared, and structurally characterized as potential multichannel heteroditopic receptors for ions. The versatility of the bottom arm formation enables the decoration of the triad core with an additional nitrogen-based binding site, linked to substituents displaying different optical properties. As a consequence, the resulting disubstituted ferrocene derivatives have been shown to be excellent anion, cation, and ion pair multichannel recognition receptors. In order to gain insight into the coordination modes and into the nature of the anion contact ion pair formed, quantum chemical calculations were also carried out.