Novel ion recognition systems based on cyclic and acyclic oligo(salen)-type ligands

摘要: This review describes the design of novel ion recognition systems based on salen (H2salen = N,N′-disalicylideneethylenediamine) or related ligands. The phenoxo groups salen-based metallohosts play an important role in because can further coordinate to metal ions a bridging fashion. In particular, integration two more salen-type coordination sites cyclic fashion is effective for construction metallohosts. They show unique multi-metal complexation behavior and binding selectivities due phenoxo-bridged structures. peripheral are suitable d-block transition central O6 (or larger) site group 1–3 metals. Acyclic oligo(salen) molecules also obtaining metalation bis(salen)-type ligand with metals leads trinuclear complex C-shaped structure, which selectively recognize Ca2+ lanthanide(III) via exchange process. longer ligands form helical structure when they La3+ Ba2+ presence zinc(II) ion. helix inversion complexes labile character bonds successfully utilized dynamic helicity control. transformation acyclic into ones olefin metathesis significantly changes selectivity.