Coumarin–derived organosilatranes: functionalization at magnetic silica surface and selective recognition of Hg2+ ion

Abstract

This article features the first synthesis of coumarin based triazole linked organosilatranes (3–5) derived from terminal alkyne (1) via click methodology. The coumarin tethered organosilatranyl moiety was anchored on magnetic silica surface and was well characterized by numerous spectroscopic and analytical techniques. The resultant hybrid nanoparticles have been characterized in detail by FTIR, UV–vis spectroscopy, Photoluminiscence (P.L), SEM, TEM, XRD, EDX and TGA. The silatranes (3–5) were then assessed for their metal ion binding properties using absorption and emission spectra. It was observed that the synthesized compounds showed significant selectivity for Hg (II). In addition, the interacting ability of coumarin based derivatives was investigated at different pH values and the pH 9 was considered to be the most favorable pH for fluorometric analysis. Importantly, the hybrid nanoparticles possessed enhanced sensorial ability towards Hg2+ ion and these findings were affirmed using stern volmer equation. In addition, the complexation mode of silatrane (3) with Hg2+ ion was also elucidated by computational analysis using DFT study.