Self-assembly of the cyclic dimer [Cu(hfac)2(bpmu)]2 (bpmu = N,N′-bis(3-pyridylmethyl)urea; hfac = hexafluoroacetylacetonate ion) using coordination chemistry and predictable OC(N-H)2⋯OC hydrogen bonds

The new binuclear complex [Cu(hfac)2(bpmu)]2 has been isolated by treatment of Cu(hfac)2 · H2O with bpmu. The single crystal X-ray structure reveals its dimeric nature and that the units are bonded through strong intra- and intermolecular OC(N-H)2⋯OC hydrogen bonds. The formation of the discrete species can be considered as the insertion of the bulky cis-{Cu(hfac)2} fragments into the prearranged hydrogen bonded pattern provided by the bpmu tecton through the OC(N-H)2⋯OC moieties.