Hydrothermal Syntheses and Crystal Structures of Compounds Based on α- or β-[Mo8O26]4− Isomers

Using Cu(II/I)/Ni(II) complex fragments and [Bu4N]4[α-Mo8O26] as precursors, four compounds based on α- or β- octamolybdate isomers, [{Cu(tpdoen)}2][α-Mo8O26]·3H2O 1 (tpdoen = 2-(pyridin-2-ylmethoxy)-N-(2-(pyridin-2-ylmethoxy)ethyl)-N-(pyridin-2-ylmethyl)ethanamine); [{Cu(dpoen)}2(α-Mo8O26)] 2 (dpoen = 2-(pyridin-2-ylmethoxy)-N-(pyridin-2-ylmethyl)ethanamine); [{Cu(dpmea)}2(β-Mo8O26)] 3 (dpmea = N,N-diethyl-N-(pyridin-2-ylmethyl)ethanaminium); [{Ni(tpoen)}2(β-Mo8O26)]·5H2O 4 (tpoen = 2-(pyridin-2-ylmethoxy)-N,N-bis(pyridin-2-ylmethyl)ethanamine) were hydrothermally synthesized. They have been characterized by elemental analysis, FT-IR, TG analysis and single-crystal X-ray diffraction. Compound 1 is a discrete structure constructed from [α-Mo8O26]4− anions and [Cu(tpdoen)]2+ coordination cations. The coordination cations aggregate around an octamolybdate anion via hydrogen bonding interactions, forming a “flowerpot” supramolecular network. Compound 2 is constructed from [α-Mo8O26]4− anions bridged through [Cu(dpoen)]2+ fragments into a 2D layered grid. Compounds 3 and 4 are Cu(I) and Cu(II) complexes bis-supported by [β-Mo8O26]4− anions, respectively. The electrochemical behaviors of compounds 1–4 modified solid bulk-modified carbon paste electrodes (1-MCPE-4-MCPE) have been studied.