Synthesis,crystal structure and properties of a neodymium(III) coordination polymer of 1D chain structure based on typical plenary Keggin cluster

A 1D zigzag chain compound, [{Nd(NMP)₆}(PMo₁₂O₄₀)] _n , has been synthesized by reaction of α-H₃PMo₁₂O₄₀?·?nH₂O, Nd₂O₃ and NMP (NMP?=?N-methyl-2-pyrrolidone) in acetonitrile–water mixture, and characterized by elemental analysis, IR and UV spectra, and X-ray single crystal structural analysis. The crystal structure indicates that the title compound forms a one-dimensional zigzag chain built from alternating polyanions and cationic units through Mo–O_t–Nd–O_t–Mo links. In the compound, Nd³⁺ are eight-coordinate with a bicapped trigonal prism geometry of oxygen atoms, from six NMP molecules and two adjacent polyanions, and two terminal oxygen atoms of the polyanions occupying the caps. The powder ESR spectrum at 110?K of the title compound after being exposed to sunshine shows the signal of Mo⁵⁺, g?=?1.96. The CV shows that the title compound undergoes five two-electron reversible reductions and that [PMo₁₂O₄₀]^3? are active centers for electrochemical redox in solutions; cations have a small effect on electrochemical redox.