Synthesis, structure and magnetic properties of a new dimeric silicotungstate: K9Na2H[γ-Cu2(H2O)SiW8O31]∙39H2O

INOR 717

Zhen Luo, zluo@emory.edu1, Paul Kögerler, kogerler@ameslab.gov2, Rui Cao, rcao@emory.edu1, Imroz S Hakim1, and Craig L. Hill, chill@emory.edu3. (1) Department of Chemistry, Emory University, 1515 Dickcy Dr, Atlanta, GA 30322, (2) Iowa State University, Ames Laboratory, Ames, IA 50011, (3) Department of Chemistry, Emory University, Atlanta, 1515 Dickey Drive, Atlanta, GA 30322
The novel dimeric silicotungstate K9Na2H[γ-Cu2(H2O)SiW8O31]∙39H2O (1) has been synthesized and characterized by IR spectroscopy, elemental analysis, and magnetic measurements. A blue needle-like crystal of 1 was obtained by reacting K8[γ-SiW10O36] with 2 equiv of Cu(II) in a 0.5 M sodium acetate solution (pH 4.2) and mixing this solution 1:1 with ethylene glycol. The structure of 1 was determined by single-crystal X-ray diffraction: monoclinic, P21/n, Z = 2, a = 10.8173(9) Å, b = 19.5927(17) Å, c = 18.2517(16) Å, β = 90.165(2)° and R1 = 3.41% based on 9709 independent reflections. The structure consists of two [γ-Cu2(H2O)SiW8O31] Keggin units connected to each other with the [Cu2O(H2O)(μ3-O)(μ2-O)] moiety of one unit bonded to the top of a [W2O6] moiety of the other unit. The variable-temperature magnetic measurements indicate ferromagnetic coupling between the Cu(II) centers.
 

Polyoxometalates and Related Clusters in Chemistry and Nanoscience
7:00 PM-10:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, August 20, 2007 BCEC -- Exhibit Hall - B2, Sci-Mix

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007