Synthesis, crystal structure and thermal properties of two new hybrid octamolybdates supported nickel complexes

Two new organic–inorganic hybrid compounds based on polyoxometallates, [Ni(im)6][Him]2[(im)2Mo8O26]·2DMF·2H2O (1) and [Ni(im)4(DMF)2]2[(im)2Mo8O26]·2DMF·3H2O (2) (im = imidazole, DMF = N,N-dimethylformamide), have been synthesized and characterized by single crystal X-ray analysis, elemental analysis and IR spectra. The thermal properties were studied by TG analysis. Both of the two compounds consist of imidazole coordinated γ-octamolybdate anions, which firstly link to one-dimensional chains via hydrogen bonding. Then, the metal complex cations link the 1D hydrogen bonding chains to 3D frameworks by abundant hydrogen bondings.

► Two new organic–inorganic hybrid compounds have been synthesized and characterized.
► Both of them contain imidazole coordinated γ-octamolybdate anion.
► Different imidazole nickel complex cations lead to different 3D frameworks.
► It is due to their different shapes and locations of hydrogen bonding donor sites.