Expanding the structural diversity of hydrophobic ionic liquids: physicochemical properties and toxicity of Gemini ionic liquids

Abstract

Ionic liquids (ILs) have been labeled as a promising green alternative to traditional materials; however, many ILs have been discovered to be toxic, especially hydrophobic ILs (HILs). HILs are limited in their structural diversity as most are composed of heteroaromatic cations with long alkyl chains and paired with [BF₄], [PF₆], or [NTf₂] anions. This study aims to diversify HILs by synthesizing two sets of HILs with unique cations and anions. The first set of HILs contain cholinium- and dicholinium-based cations paired with the [NTf₂] anion. The [DC-ether] cation is identified as a promising cation and is paired with an array of asymmetric bis(sulfonyl)amide anions to form the second set of HILs. In total, twenty HILs are synthesized. Each HIL is characterized using traditional physicochemical techniques and is evaluted for toxicity using in vitro and in vivo methods.