Zhang S.,Nankai University |
Zhang S.,Polyoxometalates Chemistry Key Laboratory of Henan Province |
Zhang D.,Polyoxometalates Chemistry Key Laboratory of Henan Province |
Zhang D.,Henan University |
And 8 more authors.
CrystEngComm | Year: 2013
Three unprecedented trimers based on monovacant Dawson-type polyoxotungstates Na12[Ln(H2O)9] 2[(α2-P2W17O 61H4)La(H2O)4]6· 100H2O (Ln = LaIII (1)) and Na24[Ln(H 2O)8]2[(α2-P2W 17O61H2)Ln(H2O)4] 6·56H2O (Ln = CeIII (2), and Pr III (3)) have been successfully synthesized by straightforward "self assembly" processes starting from a 1:4 ratio of the saturated Dawson precursor [α-P2W18O62] 6- and Ln ions in aqueous solution, which were further characterized by elemental analyses, X-ray powder diffraction (XRPD), IR spectra, thermogravimetric (TG) analyses, electrospray ionization mass spectrometry (ESI-MS) and single-crystal X-ray diffraction. The common feature of 1-3 is that they all consist of the trimeric triangular [(α2-P 2W17O61)Ln(H2O)4] 3 21- subunit, as we know, the trimeric [(α2-P2W17O61)Ln(H 2O)4]3 21- polyoxoanion is firstly discovered. Furthermore, all three compounds can further generate three dimensional channel architectures through Na+ cations. Meanwhile, the multinuclear solution 31P NMR spectrum of 1 at 300 K in D 2O has been investigated, the results are further demonstrated by the technologies of ESI-MS. © 2013 The Royal Society of Chemistry.