Directed supramolecular assembly of Cu(II)-based 'paddlewheels' into infinite 1-D chains using structurally bifunctional ligands

摘要

The construction of Cu(II)-containing supramolecular chains is achieved by combining suitable anionic ligands (for controlling the coordination geometry and for creating a neutral building block) with four new bifunctional ligands containing a metal-coordinating pyridyl site and a self-complementary hydrogen-bonding moiety. Seven crystal structures are presented and in each case, the copper(II) complex displays a "paddlewheel" arrangement, with four carboxylate ligands occupying the equatorial sites, leaving room for the bifunctional ligand to coordinate in the axial positions. The supramolecular chemistry, which organizes the coordination-complexes into the desired infinite 1-D chains, is driven by a combination of N-H center dot center dot center dot N and N-H center dot center dot center dot O hydrogen-bonds in five of the seven structures.