Assembly of mixed-metal cages using polyimido antimony(III) anions. Syntheses and structures of [Sb-3(NCy)(4)(HNCy)(2)]K center dot 2(toluene), [Sb-2(NCy)(4)](2)M-4 (M=Cu, Ag), and [Sb(NCy)(3)](2)Pb-3 (Cy equals cyclohexyl, C6H11)

Transmetalation reactions of the polyimido Sb(III) anions [Sb-3(NCy)(4)(HNCy)(2)](-), [Sb-2(NCy)(4)](2-), and [Sb(NCy)(3)](3-) with metal sources allows the logical assembly of cage compounds containing various mixed-metal stoichiometries. The breadth of this approach is illustrated by the syntheses of [Sb(NCy)(4)(HNCy)(2)]K . 2 (toluene) (1), containing an early main group metal, [Sb-2(NCy)(4)](2)M-4 (M = Cu (2), Ag (3)), containing transition metals, and [Sb(NCy)(3)Pb-3] (4), containing a p-block metal. The low-temperature X-ray structures of complexes 1-4 have been determined. Crystal data: 1, monoclinic, space group C2/c, a = 18.318(3) Angstrom, b = 11.457(2) Angstrom, c = 24.798(6) Angstrom, beta = 90.24(2)degrees, Z = 4; 3, triclinic, space group P (1) over bar, a = 11.501(2) Angstrom, b = 13.752(3) Angstrom, c = 22.868(5) Angstrom, alpha = 103.50(3)degrees, beta = 95.89(3)degrees, gamma = 96.71(3)degrees, Z = 2; 4, triclinic, space group P (1) over bar, a = 11.071(2) Angstrom, b = 14.892(2) Angstrom, c = 17.262(2) Angstrom, alpha = 65.36(3)degrees, beta = 74.21(3)degrees, gamma = 70.70(3)degrees, Z = 2. The structure of 2 has been reported in preliminary form. The K+ ion of 1 is coordinated by four of the N centers of the [Sb-3(NCy)(4)(HNCy)(2)](-) ligand. In addition, beta-C(-H)... K interactions involving four of the Cy groups and MeC(-H)... K interactions involving two toluene molecules give the K+ ion a 10-coordinate geometry. In 2 and 3, the N centers of two [Sb-2(NCy)(4)](2-) dianions symmetrically coordinate a central M-4 square-planar core. The symmetrical complexation of three Pb(II) centers by two [Sb(NCy)(3)](3-) trianions produces an 11-membered polyhedral cage structure in 4.