Synthesis and Crystal Structure of Hydrogen Strontium Paratungstate Sr_(4.5)H[W_(12)O_(40)(OH)_2]·30H_2O

摘要

The conditions for formation of individual isopolytungstates in solutions of the Sr(NO_3)_2—Na_2WO_4—HNO_3—H_2O system acidified to Z=v(H~+)/v(WO_4~(2-))= 1.29 were studied. The conditions of for-mation of strontium paratungstate B, strontium hydroheptatungstate, and hydrogen strontium paratungstatewere determined. An X-ray diffraction study of single crystals of Sr_(4.5)H[W_(12)O_(41)(OH)_2]· 30H_2O was carriedout. Selected crystallographic data for H_(63)0_(72)Sr_(4.50)W_(12)are:Mr=3815.99, monoclinic, space group P2_1/c,a = 11.41270(10) A, b = 23.7575(3) A, c=12.4392(2) A, β = 110.476(2)°, V= 3159.64(7) A~3 at T= 293 K,Z= 2, p = 4.011 g/cm~3,F_(000)= 3396, μ(MoK_α) = 25.635 mm~(-1),-14≤h≤14, -30≤k≤30, -16 ≤l≤16,R_F = 0.0430, wR~2= 0.1067 (R_F= 0.0506, wR~2= 0.1129), and S=1.043.