"Inherently Chiral" Ionic Liquids Achieving effective chiral electroanalysis on achiral electrodes

In "inherently chiral" molecular materials the coincidence of the stereogenic element bt with the molecular portion responsible for their specific properties was shown to result F< bi ionic media, liquid in some cases, 1 and 2 have been prepared in which the stereogenic in outstanding enantioselectivity as electrode surfaces. 1 In this work, inherently chiral b, core responsible for chirality is an atropisomeric I, I'-bibenzimidazolium or 3,3'¬ th bipyridinium system. They can be prepared by double alkylation of the corresponding neutral scaffolds, which can be synthesized in turn starting from inexpensive reagents. The resolution of the racemates into configurationally stable enantiomers is effected by semi-preparative HPLC on CSP in the former case and by crystallization of the diastereeomeric salts with D- and L-O,O-dibenzoyltartaric acids in the latter. While the double bi-benzimidazolium salts are high-melting solids, some bicollidinium analogous are liquid at room temperature. Both the new inherently chiral ILs and shorter family terms, solid at room T, employed as low concentration additives in commercial achiral ionic liquids, afford outstanding enantiodiscrimination of structurally different chiral probes (L- and D-DOPA and their methyl esters, (R)- and (S)-N,N-dimethyl-I-ferrocenylethylamines and the antipodes of a chiral oligothiophene) on achiral electrodes. The oxidative peaks of the probe enantiomers differ fom 100 to a spectacular 360 mV value. I) Sannicolo, F.; Arnaboldi, S.; Benincori, T.; Bonometti, Y.; Cirilli. R.; Dunsch, L.; Kutner. W.; Longhi, G.; Mussini, P. R.; Panigati, M.; Pierini, M.; Rizzo, S. Angew. Chern. into Ed. 2014,53,2623¬ 27; Arnaboldi, S.; Benincori, T.; Cirilli, R.; Kutner, W.; Magni, M.; Mussini, P.R.; Noworyta, K.; Sannicolo, F. Chemical Science 2015,6. 1706-1711.