No abstract

The reactions of a variety of primary and secondary amines and secondary phosphanes with “GaI” have been examined. In all cases disproportionation reactions occurred which led to the gallium(II) iodide complexes [Ga2I4(L)2] [L = NCyH2, NtBuH2, NCy2H, PCy2H or PtBu2H (Cy = cyclohexyl)]. All complexes have been crystallographically characterised and have been shown to be dimers possessing Ga−Ga bonds. The reaction of the sterically hindered N‐heterocyclic carbene IPr [:CN(Ar)C2H2N(Ar) (Ar = C6H3iPr2‐2,6)] with “GaI” was also carried out and the novel salt [Ga2I5(IPr)][IPrH] was formed in good yield and crystallographically characterised. Finally, the related reaction of the less hindered cyclic carbene IMe [:CN(Me)C2Me2N(Me)] with InCl gave a low yield of the crystallographically characterised salt [{InCl(IMe)}2(μ‐Cl)(μ‐O)][Cl] which presumably forms due to the presence of adventitious oxygen in the reaction mixture. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Rare earth carbodiimides with the general formula RE 2(CN 2) 3 crystallize with two modifications. A monoclinic( C2/m) modification is obtained for RE = Y, Ce-Tm and a rhombohedral ( R3 c) modification for RE = Tm-Lu. The space group R3 c is confirmed by single-crystal structure determination on Lu 2(CN 2) 3 and indexed powder patterns of RE = Tm, Yb and Lu. The use of diverse chemical syntheses conditions for Tm 2(CN 2) 3 revealed the dimorphic character of this compound. In addition, pressure experiments on Tm 2(CN 2) 3 have induced a phase-transition from rhombohedral to monoclinic. This transformation comprises an increase of the coordination number of Tm from 6 to 7, and a unit-cell volume reduction in the order of 20 %. The photoluminescence behavior of lanthanide doped Gd 2(CN 2) 3:Ln samples is presented with different activators (Ln = Ce, Tb) revealing a broad band emission of Gd 2(CN 2) 3:Ce, quite similar to that of the well-known YAG:Ce.

Tetracyanamidosilicates of the type ARE[Si(CN(2))(4)] with A = K, Rb, and Cs and RE = Y and La-Lu have been prepared by a solid-state metathesis reaction. The potassium compounds with RE = La-Gd crystallize orthorhombically in the space group P2(1)2(1)2. Rubidium as well as cesium compounds crystallize tetragonally in the space group I4. The luminescent properties of ARE[Si(CN(2))(4)]:Ln compounds with RE = Y, La, and Gd doped with 5 mol % Ln = Ce, Eu, or Tb were investigated. Temperature-dependent magnetic susceptibilities were measured for KGd[Si(CN(2))(4)]. The value of the magnetic moment is 7.3 mu(B)/Gd(3+) ion, which is in line with the expected value for the [Xe]4f(7) configuration of Gd(3+).

The reduction of tungsten hexachloride with bismuth yields the new compound (BiCl)[W 6 Cl 14 ]. Dissolution of this compound in HCl yields the cluster acid (H