The C–H⋯Cl2Cu(II) synthon in the structural direction and assembly of supramolecular complexes with the 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine ligand and its N-substituted derivatives

Three new Cu(II) supramolecular complexes [Cu(L1)Cl2]·2DMF (1), [Cu(L2)Cl2] (2) and [Cu(L3)Cl2]·DMF (3) (L1 = 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine, L2 = 3,3′- bis(N-ethyl-2-benzimidazolyl)-2,2′-dipyridine and L3 = 3,3′-bis(N-benzyl-2-benzimidazolyl)-2,2′-dipyridine) have been prepared and characterized by elemental analysis, IR spectra and single crystal X-ray diffraction. X-ray structural analysis of L1, L2·3.5H2O and L3·H2O indicates that all three ligands adopt the trans conformation with the two benzimidazole fragments located on opposite sides of the dipyridyl backbone. While in complexes 1–3, all the ligands display the cis conformation and behave as bidentate chelating reagents to coordinate with Cu(II). The inorganic chloride ions always act as a reliable hydrogen bonded acceptor in these structures, and the resulting C–H⋯Cl2Cu supramolecular synthons play a significant role in the formation and stabilization of the structures. Moreover, additional non-covalent interactions, such as C–H⋯π, are also identified to extend the discrete (0-D) or low-dimensional (1-D) motifs into high-dimensional architectures.

Three new Cu(II) supramolecular complexes were constructed from the 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine ligand and its N-substituted derivatives. In the three crystal structures, the C–H⋯Cl2Cu supramolecular synthons, play a significant role in the formation and stabilization of the structures, and additional non-covalent interactions, such as C–H⋯π, can extend the discrete (0-D) or low-dimensional (1-D) motifs into high-dimensional architectures.Figure optionsDownload as PowerPoint slide