Construction of a series of 0D, 2D and 3D inorganic–organic hybrid coordination polymers based on octamolybdate and 2-(2-pyridyl)imidazole and its derivative

Four octamolybdate-based compounds, that is, CuII2(L1)4(Mo8O26) (1), CuII2(HL2)4(Mo8O26)2 (2), [CuIIL2(H2O)(Mo8O26)0.5]·2H2O (3) and [CuIIL2(H2O)(Mo8O26)0.5]·2H2O (4) (L1 = 2-(2-pyridyl)imidazole, L2 = 2-(1-(pyridine-3-ylmethyl)-1H-imidazol-2-yl)pyridine), have been hydrothermally synthesized via changing the reaction conditions and structurally characterized by single-crystal X-ray diffraction. With L1 ligand, we obtained compound 1, which is a 0D molecule and extends to a 3D supramolecular structure via hydrogen-bonding interactions. By using L2 instead of L1 ligand, compound 2 comes into being which is as well a discrete molecule and further extended to a 3D supramolecular structure by hydrogen bonds. Intriguingly, compounds 3 and 4 are supramolecular isomers: the former is a 2D 4-connected network and the latter is a 3D (3,4)-connected framework. The measurements of diffuse reflectance for compounds 1–4 indicate that they are potential wide gap semiconductors.

Graphical abstractFour new octamolybdate-based compounds have been attained via changing several influencing factors and characterized by single-crystal X-ray diffraction. Compounds 1 and 2 are discrete molecules and further extended to 3D supramolecular structures by hydrogen bonds. Intriguingly, compounds 3 and 4 are supramolecular isomers: the former is a 2D 4-connected network and the latter is a 3D (3,4)-connected framework.Figure optionsDownload full-size imageDownload as PowerPoint slide