title: A self-assembled Pd2L4 cage that selectively encapsulates nitrate.
abstract: A M2L4 cage with D4 symmetry was self-assembled from four anthracene-bridged benzimidazole ligands and two Pd(II) ions. The cage features a concise hydrophobic pocket wrapped up by the anthracene walls with eight hydrogen-bond donors pointing inward, which provide a specific binding site for nitrate, with a binding affinity at least two orders of magnitude higher than all the other anions screened including halide anions, which have a very similar ionic radius and charge density.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China. qfsun@fjirsm.ac.cn.
authors.forename: Li-Peng
authors.initials: LP
authors.lastname: Zhou
authors.forename: Qing-Fu
authors.initials: QF
authors.lastname: Sun