Breaking the paradigm: record quindecim charged magnetic ionic liquids

Abstract

A family of bis(trifluoromethanesulfonyl)amide-based ionic liquids of composition [RE₅(C₂H₅-C₃H₃N₂-CH₂COO)₁₆(H₂O)₈](Tf₂N)₁₅ (RE = Er, Ho, Tm; C₃H₃N₂ ≡ imidazolium moiety) featuring the cationic, record quindecim {15+} charged pentanuclear rare earth (RE)-containing ion [RE₅(C₂H₅-C₃H₃N₂-CH₂COO)₁₆(H₂O)₈]¹⁵⁺ has been synthesized and characterized. In addition, due to the presence of rare earth ions, these ionic liquids show a response to magnetic fields with the highest effective magnetic moment observed so far for an ionic liquid and are rare examples of ionic liquids showing luminescence in the near-infrared. These ionic liquids also were successfully employed in a three-component synthesis of 2-pyrrolo-3′-yloxindole with an extremely low (<0.035 mol%) catalyst loading rate.