Bisphosphonate salts as covalent and non-covalent task-specific ionic liquid synthesis

Abstract

Functionalized ionic liquids, commonly referred to as task-specific ionic liquids (TSILs), represent a distinct subset within the realm of ILs. They stand out by having a functional group covalently bonded to either the cationic or the anionic counterpart of the ionic liquid. These tailored modifications confer specific properties to TSILs, making them well-suited for various applications, including catalysis, liquid–liquid extraction, and synthesis. Notably, they also find relevance in the field of nanomaterials. In this paper, we delineate the synthetic pathway for TSILs featuring imidazolinium or pyridinium cores functionalized with a bisphosphonate unit. Furthermore, we provide detailed insights into the green synthesis of imidazolinium salts constituted by a bisphosphonate moiety as the counterion. These innovative TSILs, characterized by a bisphosphonate group, pave the way for a new avenue in the selective complexation of strategic metals and the development of new drugs.¹ This underscores their potential utility in strategic metal recovery by extraction and related endeavors.