Reduced lanthanum halides with Ge as interstitials: La2I2Ge, La2I2Ge2, La3Cl2Ge3, La3Br2Ge3, La3I3Ge, La6I5Ge3 and La7+xI12Ge

The title compounds were synthesized from La, LaX3 (X = Cl, Br and I) and Ge under Ar atmosphere at temperatures 860-1200 degreesC. Their structures are characterized by Ge-centered La-6 octahedra or trigonal prisms. Ge atoms form planar zigzag [ttctct](infinity) (t = trans, c = cis) chains in La3Br2Ge3 and La3Cl2Ge3, graphite-like hexagon nets in La2I2Ge2, but otherwise are not bonded to each other in La2I2Ge, La2I2Ge2, La3I3Ge, La6I5Ge3 and La7+xI12Ge (x approximate to 0.7). Computational structures of these compounds was carried out.