Preparation, Structural Characterization, Electrochemistry, and Sensing Properties toward Anions and Cations of Ferrocene-Triazole Derivatives

Abstract

A number of monosubstituted (3, 4, 6, 8, 9, 11, and 13) and disubstituted (15 and 16) ferrocene-derived triazoles have been prepared, by using the copper-catalyzed click reaction, and fully characterized. The versatility of the click reaction enables the decoration of the ferrocene-triazole core, with additional substituents displaying different optoelectrochemical properties. The most salient features derived from the sensing studies are that receptors 3, 6, 15, and 16 undergo unprecedented cathodic shifts of the oxidation peak of the ferrocene/ferrocenium redox couple in the presence of F–, AcO–, H2PO4 –, and HP2O7 3– anions, whereas receptors 11 and 16 behave as dual redox and optically selective molecular sensors for Hg2+ cations. The isolated [6 3·Ni2+] complex has been characterized by X-ray analysis.

Halogen bonding-enhanced electrochemical halide anion sensing by redox-active ferrocene receptors

“…5 These receptor molecules typically contain ferrocene as the redox-active moiety due to its chemical stability, favourable voltammetric characteristics and large synthetic repertoire, allowing it to be readily incorporated into a myriad of molecular architectures. [6][7][8][9][10][11][12] As a result, ferrocene-containing anion sensors utilising hydrogen bonding (HB), Coulombic interactions, as well as Lewis acid and metal coordination have been reported. [13][14][15] Halogen bonding (XB), a highly-directional attractive non-covalent interaction between a Lewis-acidic halogen atom and a Lewis base, 16 is a recent addition to the toolkit of supramolecular anion binding in solution.…”

Ferrocene-containing macrocyclic triazoles for the electrochemical sensing of dihydrogen phosphate anion

“…As a result, the electron density on the anion is transferred to the ferrocenyl center of the hosts, inducing a facile oxidation of the ferrocene moiety of the receptor into ferrocenium ion. The triazole-based receptors often show good binding abilities toward phosphate anions [41][42][43][44]56]. The CV and DPV titrations of the receptors L1-L4 in presence of the H 2 PO 4 À anion were investigated (Figs.…”

“…Many ferrocene-based receptors for anions recognition have been reported, which reveal a large shift in the redox potential of the ferrocene/ferrocenium redox couple toward cathodic potential when target anions are added to the media [34][35][36][37][38][39][40]. In addition, triazole functionalized ferrocenes for anions recognition, especially phosphate ions, have also been reported [41][42][43][44]. However, most of them are limited to acyclic systems.…”

Selective sensing ability of ferrocene appended quinoline-triazole derivative toward Fe (III) ions

“…Several electrochemical sensing systems were designed by assembling ferrocene unit with different binding motifs [16][17][18]. Among them, 1,2,3 triazole motif has proved to be an efficient binding unit for recognition of various cations as well as anions [19,20]. Recently, the combination of ferrocene unit (signaling unit) with triazole (binding unit) proved as an efficient electrochemical sensing platform for the detection of various analytes and therefore, this mingle system has huge analytical value and applications in the field of electrochemical sensing [21,22].…”