Molecular structure of GdCl3. Nuclear dynamics of the trichlorides of Gd, Tm, and Lu

Abstract

The structure of gadolinium trichloride has been studied by joint gas-phase electron diffraction and mass spectrometry at T = 1160 K. The following thermal-average parameters have been determined: r_g(Gd–Cl) = 247.4(5), r_g(Cl⋯Cl) = 422.0(16), l_g(Gd–Cl) = 9.6(1), l_g(Cl⋯Cl) = 33.3(12) pm, Cl–Gd–Cl 117.0(11)°. A dynamic model taking into account the out-of-plane bending vibration anharmonicity was applied in the analysis. Previously obtained experimental data for LuCl₃ and TmCl₃ were also reanalysed using this model. Analysis in terms of the dynamic model indicates that GdCl₃, LuCl₃, and TmCl₃ all have planar (D_3h) equilibrium structures.