Structure-directing forces in intercluster compounds of cationic [Ag(14)(C[triple bond]CtBu)(12)Cl](+) building blocks and polyoxometalates: long-range versus short-range bonding interactions.

Crystallization of [Ag(14)(C[triple bond]CtBu)(12)Cl][BF(4)] and different polyoxometalates in organic solvents yields a series of new intercluster compounds: Ag(14)(C[triple bond]CtBu)(12)Cl(CH(3)CN)[W(6)O(19)] (1), (nBu(4)N)Ag(14)(C[triple bond]CtBu)(12)Cl(CH(3)CN)[PW(12)O(40)] (2), and Ag(14)(C[triple bond]CtBu)(12)ClAg(14)(C[triple bond]CtBu)(12)Cl(CH(3)CN)[SiMo(12)O(40)] (3). Applying the same technique to a system starting from polymeric {[Ag(3)(C[triple bond]CtBu)(2)][BF(4)]0.6 H(2)O}(n) and the polyoxometalate (nBu(4)N)(2)[W(6)O(19)] results in the formation of [Ag(14)(C[triple bond]CtBu)(12)(CH(3)CN)(2)][W(6)O(19)] (4). Here, the Ag(14) cluster is generated from polymeric {[Ag(3)(C[triple bond]CtBu)(2)][BF(4)]0.6 H(2)O}(n) during crystallization. In a similar way, [Ag(15)(C[triple bond]CtBu)(12)(CH(3)CN)(5)][PW(12)O(40)] (5) has been obtained from {[Ag(3)(C[triple bond]CtBu)(2)][BF(4)]0.6 H(2)O}(n) and (nBu(4)N)(3)[PW(12)O(40)]. The use of charged building blocks was intentional, because at these conditions the contribution of long-range Coulomb interactions would benefit most from full periodicity of the intercluster compound, thus favoring formation of well-crystalline materials. The latter has been achieved, indeed. However, as a most conspicuous feature, equally charged species aggregate, which demonstrates that the short-range interactions between the "surfaces" of the clusters represent the more powerful structure direction forces than the long-range Coulomb bonding. This observation is of significant importance for understanding the mechanisms underlying self-organization of monodisperse and structurally well-defined particles of nanometer size.