Selective Anion Recognition by a Dynamic Quadruple Helicate

An M 2 L 4 quadruple helicate, formed by wrapping four molecules of 1,4‐bis(3‐pyridyloxy)benzene ( L 1 ) about two palladium(II) centers, is shown to bind anions within its internal cavity. 1 H NMR exchange experiments provide a quantitative measure of anion selectivity and reveal a preference for ClO 4 − over the other tetrahedral anions BF 4 − and ReO 4 − and the octahedral anion PF 6 − . X‐ray crystal structures of [Pd 2 ( L 1 ) 4 ] 4+...