A Series of Multi-Dimensional Lanthanide-Containing Peroxoisopolymolybdates

A series of novel lanthanide-containing peroxo-isopolyoxomolybdates, Na2(NH4)3[H3Ln6(H2O)26(MoO4)­{Mo7O22(O2)2}4]·nH2O [n = 24; Ln = CeIII (1), PrIII (2), SmIII (3), EuIII (4); n = 25; Ln = NdIII (5)] and Na4(NH4)3[H4La5(H2O)21(MoO4)­{Mo7O22(O2)2}4]·17H2O (6) have successfully been synthesized by the conventional method and further characterized by elemental analyses, X-ray photoelectron spectroscopy, X-ray powder diffraction, IR and UV spectra, thermogravimetric analyses, and single-crystal X-ray diffraction. All of the six compounds are composed of the [Ln4(H2O)16(MoO4)­{Mo7O22(O2)2}4]14– polyoxoanion. 1–5 can further generate two-dimensional structures through LnIII cations, whereas 6 shows the one-dimensional chain structure linked by LaIII cations. These compounds represent the first examples of introducing peroxo groups into the lanthanide-containing isopolyoxomolybdates. 1 is selected as an example to investigate the electrochemical behavior of these compounds. In addition, the fluorescence analyses of 3 and 4 have been studied. The spectra exhibit obvious fluorescence signals of SmIII and EuIII cations.