Synthesis and characterization of PY2- and TPA-appended diphenylglycoluril receptors and their bis-CuI complexes

A number of metallohosts mimicking dinuclear copper oxygenases have been designed and synthesized. These metallohosts combine a substrate binding site, i.e. the diphenylglycoluril basket receptor, with two types of metal-binding ligands, viz. tri-coordinating bis(2-ethylpyridine)amine (PY2) and tetra-coordinating tris(2-methylpyridine)amine (TPA). The preparation of the bis-Cu' complexes of the ligand-appended receptors and their characterization by NMR are reported. NMR spectroscopic data provide evidence for a dynamic inclusion behavior of some of the pyridine moieties in the receptor of both the metal-free ligands and the Cu-1 complexes. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)