Synthesis and crystal structure of cerium heteropolyoxotungstate K4.5Na4 (H3O)(3.5) [Ce(SiW11O39)(2)]center dot 23H(2)O

The lacunary cerium heteropolyoxotungstate K4.5Na4(H3O)(3.5)[Ce(SiW11O39)(2 )]. 23H(2)O has been synthesized, and determined by X-ray diffraction metho d. This compound crystallizes in the triclinic space group P (1) over bar w ith a = 16.531(4), b = 23.193(4), c = 12.764(2) Angstrom, alpha = 99.740(6) , beta= 91.90(1), gamma = 94.84(1)degrees V=4801(2) Angstrom (3), M-r:=6180 .91, Z=2, D-c= 4.276 g.cm(-3), mu (MoK alpha)= 27.06 mm(-1), F(000)= 5359. Final R=0.07 81 (wR = 0.1838) for 11936 observed reflections with I>2 sigma (I). Two lacunary (alpha -SiW11O39) units are connected by a cerium cation . The cerium cation is coordinated by eight oxygen atoms, resulting in a di storted dodecahedron with the Ce-O bond lengths ranging from 2.39(2) to 2.4 5(2) Angstrom. The Si atom is coordinated by three mu (4)-O oxygen atoms an d one mu (4)-O Oxygen atom, respectively.