title: Assembly of Mixed-Metal Cages Using Polyimido Antimony(III) Anions. Syntheses and Structures of [Sb(3)(NCy)(4)(HNCy)(2)]K.2(toluene), [Sb(2)(NCy)(4)](2)M(4) (M = Cu, Ag), and [Sb(NCy)(3)](2)Pb(3) (Cy = Cyclohexyl, C(6)H(11)).
abstract: 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 = 18.418(3) Å, b = 11.457(2) Å, c = 24.798(6) Å, beta = 90.24(2) degrees, Z = 4; 3, triclinic, space group P&onemacr;, a = 11.501(2) Å, b = 13.752(3) Å, c = 22.868(5) Å, alpha = 103.50(3) degrees, beta = 95.89(3) degrees, gamma = 96.71(3) degrees, Z = 2; 4, triclinic, space group P&onemacr;, a = 11.071(2) Å, b = 14.892(2) Å, c = 17.262(2) Å, 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.
authors.affiliation: Chemistry Department, Cambridge University, Lensfield Road, Cambridge CB2 1EW, U.K.
authors.forename: Michael A.
authors.initials: MA
authors.lastname: Beswick
authors.forename: Natalie L.
authors.initials: NL
authors.lastname: Cromhout
authors.forename: Christopher N.
authors.initials: CN
authors.lastname: Harmer
authors.forename: Michael A.
authors.initials: MA
authors.lastname: Paver
authors.forename: Paul R.
authors.initials: PR
authors.lastname: Raithby
authors.forename: Moira-Ann
authors.initials: MA
authors.lastname: Rennie
authors.forename: Alexander
authors.initials: A
authors.lastname: Steiner
authors.forename: Dominic S.
authors.initials: DS
authors.lastname: Wright