Supramolecular chemistry based on [W3S4(H2O)6Cl3]+ -: A versatile building block

The cluster [W3S4(H2O)(6)Cl-3](+) (which is present in solutions of [W3S4(H2O)(9)](4+) in 1-4 M HCl) reacts with the macrocyclic cavitand cucurbituril (C36H36N24O12) to form supramolecular adducts of 2:1 cluster/cucurbituril stoichiometry, where two portals of cucurbituril (which contains a water molecule in its cavity) are closed by two cluster cations. These aggregates are bound together in the solid by complementary hydrogen bonds between coordinated Cl- and the cations H9O4+ to give chains. Thus, a supramolecular architecture is achieved from three different but complementary building blocks. The packing of the chains affords a honeycomb structure (hexagonal symmetry) with channels (about 5.2 Angstrom in diameter). The overall stoichiometry is (H9O4){[W3S4(H2O)(6)Cl-3](2)(C36H36N24O12)}Cl-3.16.15H(2)O (1). [W3S4(H2O)(6)Cl-3](+) reacts with SbCl3 in 6 M HCl to give cuboidal [W-3(SbCl3)S-4(H2O)(6)Cl-3](+), which forms with the macrocyclic cavitand cucurbituril a 2: 1 cluster/cucurbituril adduct - a discrete supramolecule consisting of five independent molecular units. In the solid it crystallizes as a salt of very rare anion [SbCl6](3-) with the stoichiometry {[W-3(SbCl3)S-4(H2O)(6)Cl-3](2)(C36H36N24O12)}(SbCl6)(2/3).12H(2)O (2). ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheirn, Germany, 2004).