Synthesis and characterization of three novel inorganic/organic hybrid materials based on polyoxomolybdate clusters: an investigation into the structural consequences of steric effect of the organoimine ligands

Hydrothermal means have been employed in isolating three new compounds, [Cu2Mo4O13(C5H6N2)2·3H2O] (1), [Cu2Mo4O13(C6H8N2)2] (2) and [CuMo6O19(C18H24N2)] (3) from mixtures of CuNO3/CuSO4, the corresponding ligands (methylpyrazine, dimethylpyrimidine and ditertiarybutyl-2,2′-bipyridine) and MoO3 at temperatures from 120 to 160 °C. The structures of these compounds range from three-dimensional in the case of 1 to ‘zero-dimensional’ or molecular in the case of 3 in accordance with the extent of steric hindrance presented by the ligand.