Heteroatomic deltahedral clusters of main-group elements: synthesis and structure of the Zintl ions [In4Bi5]3-, [InBi3]2-, and [GaBi3]2-

Reported are the first heteroatomic deltahedral Zintl ions made of elements differing by more than one group, indium or gallium and bismuth. Nine-atom clusters In4Bi5]3- are characterized in two different compounds, (Na-crypt)3In4Bi5] (4, P2(1)/n, a = 23.572(6) A, b = 15.042(4) A, c = 24.071(4) A, beta = 106.00(3) degrees, Z = 4) and (K-crypt)6In4Bi5]In4Bi5].1.5en.0.5tol (5, P2(1)/c, a = 28.532(2) A, b = 23.707(2) A, c = 28.021(2) A, beta = 93.274(4) degrees, Z = 4). Tetrahedra of InBi3]2- or GaBi3]2- are found in (K-crypt)2InBi3].en (1, P2(1), a = 12.347(4) A, b = 20.884(4) A, c = 12.619(7) A, beta = 119.02(4) degrees, Z = 2) and in the isostructural (Rb-crypt)2InBi3].en (2, a = 12.403(8) A, b = 20.99(1) A, c = 12.617(9) A, beta = 118.83(4) degrees) and (K-crypt)2GaBi3].en (3, a = 12.324(5) A, b = 20.890(8) A, c = 12.629(5) A, beta = 118.91(3) degrees). All compounds are crystallized from ethylenediamine/crypt solutions of precursors with nominal composition "A5E2Bi4" where A = Na, K, or Rb and E = Ga or In. The cluster in 4 is a well-ordered monocapped square antiprism with the four indium atoms occupying the five-bonded positions. Compound 5 contains two independent In4Bi5]3- clusters; one is the same as the cluster in 4, while the other is a tricapped trigonal prism with two elongated prismatic edges. All compounds are EPR-silent and therefore diamagnetic.