Assembly of [V15Sb6O42(H2O)]6- cluster shells into higher dimensional aggregates via weak Sb•••N/Sb•••O intercluster interactions and a new polyoxovanadate with a discrete [V16Sb4O42(H2O)]8- cluster shell

Systematic variation of reaction parameters such as reaction temperature and concentration of the amine under solvothermal conditions using NH4VO3, Sb2O3, CoCl2 center dot 6H(2)O and tris(2-amino)ethylamine (tren) led to the formation of three new antimonato polyoxovanadates: {Co(tren)(H2O)}(3)[V15Sb6O42(H2O)]center dot H2O (1), {Co-2(tren)(3)}(2){Co(tren)(en)}[{V15Sb6O42(H2O)(Co(tren)(2))}V15Sb6O42(H2O)]center dot xH(2)O (x approximate to 11) (2) and {Co(tren)(trenH(2))}(2)[V16Sb4O42(H2O)]center dot 6H(2)O (3). The structures of 1 and 2 are composed of [V15Sb6O42(H2O)](6-) cluster anions, which weakly interact with each other through relatively short Sb center dot center dot center dot O bonds. The transition metal complex {Co(tren)(H2O)}(2+) acts as a counter ion in 1. In 2 charge neutrality is achieved by the two cations {Co-2(tren)(3)}(4+) and {Co(tren)(en)}(2+) which are isolated and by {Co(tren)(2)}(2+) being bound to one cluster anion. The main structural motifs in compound 3 are the [V16Sb4O42](8-) cluster shell and isolated {Co(tren)(trenH(2))}(4+) cations. The structures of all three cluster anions can be derived from the {V18O42} archetype by replacing three VO5 moieties by three Sb2O3 units in 1 and 2 and by substituting two VO5 square pyramids by two Sb2O3 groups in 3.