Ordnung muss sein: heteroelement order and disorder in polyoxovanadates

摘要

The first mixed antimonato-germanato polyoxovanadates were synthesized using two different strategies, highlighting the critical role of the precursors. Following the traditional route using multiple single sources as precursors the polyanions [V15Sb2Ge4O42(OH)(4)(H2O)](6-) (1) and [V15Sb3Ge3O42(OH)(3)(H2O)](6-) (2) are obtained, which display disorder of their Sb/Ge positions, indicating that clusters of different compositions are in equilibrium in solution. In contrast, if the water-soluble single-source precursor {Ni(en)(3)}(3)[V15Sb6O42(H2O)]center dot ca. 15H(2)O is reacted with GeO2, {Ni(en)(3)}(3)[V15Sb3Ge3O42(OH)(3)(H2O)]approximate to 9H(2)O (3) forms, in which Sb and Ge occupy distinct positions that might have been formed via partial substitution reactions in the {V15Sb6} precursor.