Assembly Chemistry between Lanthanide Cations and Monovacant Keggin Polyoxotungstates: Two Types of Lanthanide Substituted Phosphotungstates [{(alpha-PW(11)O(39)H)Ln(H(2)O)(3)}(2)](6-) and [{(alpha-PW(11)O(39))Ln(H(2)O)(eta(2),mu-1,1)-CH(3)COO}(2)](10-)

作者：Niu Jingyang; Wang Kaihua; Chen Huanni; Zhao Junwei; Ma Pengtao; Wang Jingping^*; Li Mingxue; Bai Yan; Dang Dongbin

来源：Crystal Growth & Design, 2009, 9(10): 4362-4372.

DOI：10.1021/cg900248j

Two 2:2 types of monolanthanide substituted polyoxometalates [{(alpha-PW(11)O(39)H)Ln(H(2)O)(3)}(2)](6-) (Ln=Nd(III) for 1 and Gd(III) for 2) and [{(alpha-PW(11)O(39))Ln(H(2)O)(eta(2),mu-1,1)-CH(3)COO}(2)](10-) (Ln=Sm(III) for 3, Eu(III) for 4, Gd(III) for 5, Tb(III) for 6, Ho(III) for 7 and Er(III) for 8) have been synthesized in aqueous solution and characterized by elemental analyses, IR spectra, UV-vis-NIR spectra, thermogravimatric analyses and single-crystal X-ray diffraction. The common structural features are that they are constructed from monovacant Keggin-type polyoxoanions [alpha-PW(11)O(39)](7-) and trivalent lanthanide cations. Both 1 and 2 are essentially isomorphous, and the molecular structure is built by two symmetrically related monolanthanide substituted Keggin units [alpha-PW(11)O(39)Ln(H(2)O)(3)](4-) linked via two Ln-O-W bridges, representing the first monovacant Keggin polyoxotungstate dimers constituted by two [alpha-PW(11)O(39)](7-) polyoxoanions and two lanthanide cations in polyoxometalate chemistry. 3-8 are also isostructural and display another dimeric structure constructed from two monolanthanide substituted units [(alpha-PW(11)O(39))Ln(H(2)O)(eta(2),mu-1,1)-CH(3)COO](5-) bridged by two (eta(2),mu-1,1)-acetato ligands. The photoluminescence properties of 4 and 6 were investigated at room temperature. Magnetic susceptibility measurements of 1, 3, 4, 7 and 8 between 2 and 300 K exhibit that their magnetic behaviors mainly result from the spin-orbital coupling interactions as well as weak antiferromagnetic exchange interactions within magnetic centers. The electrochemical properties of 1, 3, 4, 5, 7 and 8 were studied by means of cyclic voltammetry in aqueous solution with 0.5 M Na(2)SO(4) as supporting electrolyte.

• 出版日期2009-10
• 单位河南大学