Template and coordination interactions of 4,4′-bipyridine (Bipy) in nickel(II) complexes of 2-propyl-4,5-dicarboxylate-imidazole

Two nickel(II) complexes, (H2Bipy)0.5[Ni(H2PIDC)3]·(Bipy)·5H2O (1) and [Ni(H2PIDC)2(Bipy)]n (2) (H3PIDC = 2-propyl-4,5-dicarboxylate-imidazole, Bipy = 4,4′-bipyridine), have been solvothermally synthesized and structurally characterized by infrared spectra (IR), elemental analysis, thermogravimetic analysis (TG), and single-crystal/powder X-ray diffraction. The single-crystal X-ray diffraction analysis indicates that 1 is a mononuclear coordination compound, in which the [Ni(H2PIDC)3]− coordination units are connected together through indirect hydrogen interactions to form a 3D supramolecular structure with 1D supramolecular channels. The Bipy and H2Bipy2+, as templates, fill in the channels. 2 is a 1D chain-shaped coordination polymer, in which the Bipy molecules serve as bridging ligand linking the [Ni(H2PIDC)2] units together to form a 1D chain. Through the interactions of intermolecular hydrogen bonds, these 1D chains are further stacked together to form a 3D overpass-like supramolecular network.