Directed Self-Assembly of C-Symmetric, Oxidovanadate-Centered, Vanadyl(V) Quadruplexes for Ba- and Hg-Specific Recognition, Transport, and Recovery.

Directed assembly of loosely, Na-bound, oxidovanadate-centered quartets of C-symmetry from tailor-made chiral N-salicylidene-vanadyl(V) complexes, for the first time, allows for highly efficient Ba- or Hg-specific detection (by V NMR and VCD), transport (forming a unique helical capsule or a capped square planar complex, respectively), and green recovery from an aqueous phase containing 4 different alkaline earth ions or from at least 10 different metal ions of similar size and charge capacity into the CHCl layer without interference from oxa- or oxophilic ions like Mg, Ca, Cu, Cd, and Pb.