2.B.51. The Pnictogenium Cation Anion Carrier (PCAC) Family
Work on the complexation of fluoride anions using group 15 Lewis acids led to investigations concerning the use of these main group compounds as transmembrane anion transporters. Thus, Park et al. 2019 reported on the anion transport properties of tetraarylstibonium and tetraarylbismuthonium cations of the general formula [Ph3PnAr]+ with Pn = Sb or Bi and with Ar = phenyl, naphthyl, anthryl, or pyrenyl. Using EYPC-based large unilamellar vesicles, Park et al. 2019 showed that these main group cations transport hydroxide, fluoride and chloride anions across phospholipid bilayers. A comparison of the properties of [Ph3SbAnt]+ and [Ph3BiAnt]+ (Ant = 9-anthryl) illustrated the favorable role played by the Lewis acidity of the central pnictogen element with respect to anion transport. [Ph3SbAnt]+ accelerated the fluoride-induced hemolysis of human red blood cells, an effect believed to be due to the transporter-facilitated influx of toxic fluoride anions (Park et al. 2019).