2.B.43. The Chalcogen-bonded Tellane Anion Carrier (CBT-AC) Family
Lee et al. 2019 introduced transmembrane anion transport with pnictogen-bonding compounds and compared their characteristics with chalcogen- and halogen-bonding analogues. Tellurium-centered chalcogen bonds are at least as active as antimony-centered pnictogen bonds (TC# 1.D.110), whereas iodine-centered halogen bonds are 3 orders of magnitude less active. Irregular voltage-dependent single-channel currents, high gating charges, and efficient dye leakage support the formation of bulky, membrane-disruptive supramolecular amphiphiles. due to strong binding of anions to tris(perfluorophenyl)stibanes. In contrast, the chalcogen-bonding bis(perfluorophenyl)tellanes do not cause leakage and excel as carriers with nanomolar activity, with P(Cl-/Na+) = 10.4 for anion/cation selectivity and P(Cl-/NO3-) = 4.5 for anion selectivity. The selectivities are lower with pnictogen-bonding carriers because their membrane-disturbing 3D structures also affect weaker binders ( P(Cl-/Na+) = 2.1, P(Cl-/NO3-) = 2.5). Their 2D structure, directionality, hydrophobicity, and support from proximal anion-pi interactions may contribute to the unique power of chalcogen bonds to transport anions across lipid bilayer membranes (Lee et al. 2019).