Dicationic ionic liquids as green functional materials

Over the decades, the chemistry of ionic liquids (ILs) has been extensively explored across organic synthesis, chemical processing, energy storage, biomedicine, and beyond. Monocationic ionic liquids (MILs) have dominated the field relative to dicationic ionic liquids (DILs); however, growing concerns over their environmental impact in green chemistry practices have prompted criticism over their use. DILs are known to be less environmentally deleterious, more versatile, and structurally diverse than their monocationic counterparts, but remain underrepresented in the literature. This review examines the broad applicability of DILs while focusing on environmentally conscious design strategies and practices for the future of IL chemistry. We aim to draw greater attention to the recent advances of DILs and ultimately advocate for greener approaches to IL design, development, and applicability.