Crystal structure of pentalanthanum bromotriindate, La5In3Br

Abstract

BrIn 3 La 5 , hexagonal, Pôi/mcm (No. 193), a = 9.828(2) Â, c = 6.829(3) Â, V= 571.3 Â 3 , Z= 2, R^F) = 0.030, wR^F 2 ) = 0.065, T= 293 K. Source of materialThe title compound was synthesized from stoichiometric mixtures of La, LaBn and In under Ar-atmosphere in a sealed Ta ampoule at 1173 Κ for 65 days. As the reactants and the product are air and moisture sensitive, all handling was carried out under Ar atmosphere inside a glove box or through the Schlenk technique. DiscussionThe Mn5SÌ3-type lattice is known to possess an amazing ability to host a large number of interstitials ranging from the main group elements B, C, N, O, CI, Si, Br, I to transition metals Mn, Fe, Cu, Zn, Ag and Cd, among others [1][2][3][4][5]. These compounds, derived from the Nowotny phases [6][7][8], is exemplified by LasSmBr, which has 34 valence electrons [5]. Computational analysis demonstrated that the host lattice with La as the main component is very tolerant to the variation of the number of valence electrons [5]. This has led us to attempt the synthesis of Lasher, which is the first compound with a lanthanide as the first component and a group 13 element as the second. The number of valence electrons of 31 is still within the bonding range of the host framework [5].In this contribution we present the single crystal structure of LasIn3Br. As described elsewhere [2,5], the structure consists of face-sharing La¿ octahedron chains parallel to the c-axis (see figure). These octahedra of Lai are centered by the Br species and surrounded by type 2 La (La2) and the In atoms. La2 forms chains, also parallel to the c-axis, in the channels between these La6 octahedron chains. The La2-La2 and Lai-La2 distances are 3.414(2) Â and 4.029(1) Â, respectively. The latter is shorter than the Lai-Lai distances of 4.302 Â -4.534 Â in the La« octahedron. The shortest Lai-In distance is 3.351(2) Â. The La2-In distance is 3.4750(9) Â. Thus the primary metal-metal interaction is between La2 and La2, Lai and In, Lai and La2, La2 and In. The bonding pattern has been analyzed previously [2,5].

Crystal structure of pentalanthanum trilead monoiodide, La5Pb3l

“…The anisotropy t/ii/i/33 for La(l) atoms is remarkable and also found for the equivalent atoms in other LasM^Xcompounds [3,4], LasPbsI shows metallic conductivity. …”

“…It is isostructural to LasM^X (M = In, Sn, Bi; X=CI, Br, I) [3,4] and other phases with the MnsSi3-type structure stabilized by interstitial main group atoms B -O, CI -1 and transition metals Mn, Fe, Cu, Zn, Ag, Cd [5,6]. …”