Synthese et etude structurale d'un nouvel heteropolytungstate substitue Na_8[H_3X~(III)M~(II)W_17O_59(H_2O)] ident dot 36 H_2O (X = Sb~III, Bi~III et M = Mn~(2+), Co~(2+), Ni~(2+), Cu~(2+), Zn~(2+) de structure identique a celle de [H_2X~(III)W_18O_6

摘要

By mixing an aqueous solution of antimonotungstate at pH = 4-5 and an aqueous solution of manganese(II) chloride, of cobalt(II) chloride, of nickel(II) chloride, or of zinc, a monosubstituted heteropolytungstate [H_3Sb~(III)M~(II)W_17O_59(H_2O)]~(8-) is obtained (M~II = Mn~II, Co~II, Ni~II, Zn~II). The crystallographic study, associated to EPR, XANES, EXAFS, and proton NMR spectrometries, leads to a structure identical to this of [H_2As~(III)W_18O_60]~(7-). There are two moieties Sb~(III)W_9O_30 and H_3M~(II)W_8O_30. It is concluded that the M~II atom substitutes a tungstent atom of the belt of six octahedra perpendicular to the ternary axis of the polytungstate. The same type of compound was obtained starting from bismuth chloride and copper acetate, that is [H_3Bi~(III)Cu~(II)W_17O_59(H_2O)]~(8-).