1.D.110. The Pnictogen-bonded Compound Channel (PBCC) 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, 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 (TC# 2.B.43) 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).
A pnictogen is one of the chemical elements in group 15 of the periodic table, the nitrogen family. It consists of the elements nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi).