Synthesis of Highly Selective Indole-Based Sensors for Mercuric Ion

Abstract

Two indole-based fluorescent chemosensors 1 and 2 were prepared and investigated characteristic features with transition metal ions. Sensors 1 and 2 were selective for Hg(2+) ion, among a series of metal ions, in aqueous ethanol (H(2)O-EtOH, 1:2, v/v) with association constants of 5.74 × 10(3) and 4.46 × 10(3) M(-1) and detection limits of 7.4 and 6.8 μM, respectively. Computational results revealed that sensor 1 or 2 with Hg(2+) ion formed 1:1 complex with a central, sandwich-coordinated Hg(2+) ion. Computational calculations provided evidence that a sandwich-coordinated Hg(2+) ion center was formed and the polyoxyethylene spacer acted as a scaffold for bringing functional ligands into a suitable geometry.

Bis-triazolyl indoleamines as unique “off–approach–on” chemosensors for copper and fluorine

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] In these studies, however, the indole nucleus plays a role as a receptor for F À , whereas design of prototypes in which indole exerts a tunable uorescence (FL) signal to detect metal cations has been rare. [16][17][18][19][20][21][22][23][24][25] By virtue of the Cu(I)-catalyzed azide-alkyne cycloaddition reaction (Cue-AAC) [26][27][28] that is an efficacious chemical ligation tool for constructing functional molecules, [29][30][31][32][33][34][35][36][37][38][39][40][41][42] a number of triazole-containing chemosensors have been synthesized. The triazole moiety acts not only as a simple linkage, but also participates effectively in the cation or anion recognitions.…”