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)).
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.
Beswick
Michael A.
MA
Chemistry Department, Cambridge University, Lensfield Road, Cambridge CB2 1EW, U.K.
Cromhout
Natalie L.
NL
Harmer
Christopher N.
CN
Paver
Michael A.
MA
Raithby
Paul R.
PR
Rennie
Moira-Ann
MA
Steiner
Alexander
A
Wright
Dominic S.
DS