Synthese,Kristallstruktur und Magnetismus von Natriumtetrachlorotitanat(II), Na2TiCl4

Synthesis, Crystal Structure and Magnetism of Sodium Tetrachlorotitanate(II), Na₂TiCl₄ Na₂TiCl₄ is obtained as single crystals by metallothermic reduction of TiCl₃ with sodium (525°C, 90 d, Ta container). Pure powder samples may be prepared by synproportionation of TiCl₃ with Ti in the presence of NaCl (950–520°C, 21 d). The structure refinement from four-circle diffractometer data confirms that Na₂TiCl₄ is isotypic with Sr₂PbO₄ (orthorhombic, space group Pbam (No. 55), Z = 2 a = 694.2(1), b = 1 198.9(2), c = 385.6(1) pm, R = 0.055, R_w = 0,038). Ti²⁺ is surrounded by a distorted octahedron of Cl^?. The octahedra are connected via common edges to chains, [TiCl_2/1Cl_4/2]^2?, that run in the [001] direction. Magnetic susceptibility data were recorded in the 2 to 300 K temperature range at various field strengths. The interpretation of the data was carried out with the aid of crystal-field calculations taking magnetic interactions into account. The non-Curie behaviour of the reciprocal magnetic susceptibility of Ti²⁺ in Na₂TiCl₄ is due to the influence of spin-obit coupling.