Stepwise Halide‐Triggered Double and Triple Catenation of Self‐Assembled Coordination Cages

Abstract

A simple self-assembled [Pd2 L4 ] coordination cage consisting of four carbazole-based ligands was found to dimerize into the interpenetrated double cage [3 X@Pd4 L8 ] upon the addition of 1.5 equivalents of halide anions (X=Cl(-) , Br(-) ). The halide anions serve as templates, as they are sandwiched by four Pd(II) cations and occupy the three pockets of the entangled cage structure. The subsequent addition of larger amounts of the same halide triggers another structural conversion, now yielding a triply catenated link structure in which each Pd(II) node is trans-coordinated by two pyridine donors and two halide ligands. This simple system demonstrates how molecular complexity can increase upon a gradual change of the relative concentrations of reaction partners that are able to serve different structural roles.

Anion Receptor Chemistry

“…Zhu et al 67 not result in the formation of defined complexes. Therefore, this synthesis represents an unusual example of a tetrafluoroborate peripherally templated structure.…”

Metal ions in the synthesis of interlocked molecules and materials

“…Surprisingly, addition of an excess of halide ions resulted in displacement of ligands to give a metallo- [3]-catenane composed of three interlocked dinuclear metallocycles (Fig 15). 69 Please do not adjust margins Please do not adjust margins …”

Schaltbare Wirt‐Gast‐Systeme

“…Yoshizawa wechselte zwischen Quecksilber(II)‐basierten Ringen und Käfigen durch die Ligand‐zu‐Metall‐Stöchiometrie 11. Unsere Arbeitsgruppe wandelte durch Halogenidionen monomere [Pd2L4]‐Käfige zu interpenetrierten [Pd4L8]‐Doppelkäfigen um und dann weiter zu einem Triple‐Catenan (Abbildung 4) 12…”