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.