Crystal structure of nickel paratungstate B Ni_5[W _(12)O_(40)(OH)_2]·37H_2O

摘要

From the solution of the system Na_2WO_(4-)HNO _(3-)Ni(NO_3)_(2-)H_2O acidified to Z = v(H_+)/v(WO_4~(2-)) = 1.29, the green crystals of nickel paratungstate B Ni_5[W_(12)O_(40)(OH) _2]·37H_2O are isolated. By FTIR spectroscopy the isopoly anion is shown to belong to the structural type of paratungstate B. Using single crystal X-ray analysis, the structure of Ni_5[W _(12)O_(40)(OH)_2]·37H_2O is solved (M_r = 3840.36, monoclinic, P2_1/c space group, a = 21.9061(6) ?, b = 14.9297(4) ?, c = 22.1391(6) ?, β = 107.609(3)°, V = 6901.4(3) ?~3 at T = 293 K, Z = 4, d _x = 3.696 g/cm~3, F_(000) = 6944, μ = 21.368 mm~(-1), -33 ≤ h ≤ 33, -22 ≤ k ≤ 22, -33 ≤ l ≤33; the final uncertainty values for the observed reflections are R_F = 0.0532, wR~2 = 0.0831 (R_F = 0.1088, wR~2 = 0.0894 over all independent reflections), S = 0.978; CSD-421468).