Chalcogen Bonding in Selective Recognition and Liquid‐Liquid Extraction of Perrhenate
Sourav Pramanik, Abu Saleh Musha Islam, Iti Ghosh, Pradyut Ghosh
Abstract
Abstract Efficient recognition and extraction of hazardous anionic pollutants from water medium is of great significance for environmental concerns, representing a challenging area of research in supramolecular chemistry. In this study, we present, for the first time, a comprehensive demonstration of the ability of chalcogen bonding (ChB) to recognize and remove the ReO 4 − from 100 % water medium. The anion recognition ability is well elucidated through solution phase NMR and ITC studies, which clearly reveal the selective binding of ReO 4 − over other oxo‐anions. Moreover, the selenoimidazolium scaffold effectively engages in Se•••O ChB interaction with ReO 4 − as confirmed by X‐ray crystal structure and XPS analysis. More importantly, the binding of ReO 4 − with different prolongations of the σ–holes, along with Se•••Se chalcogen bonding interactions, lead to the formation of a 1D supramolecular assembly. Eventually, ChB receptor Se 4 Me−Br exhibits ~62 % ReO 4 − extraction efficiency through precipitation as the extraction method. Furthermore, in efforts to enhance efficiency, a hydrophobic ChB receptor Se 4 Do‐PF 6 has been prepared, achieving an efficiency of up to ~93 % at a very low concentration (~5 ppm) by liquid‐liquid extraction.