摘要

The saturated vapor of lutetium tribromide was studied in the simultaneous electron diffraction and mass spectrometric experiment at 1161(10) K. Along with the monomer molecular forms, the vapor contained an insignificant (up to 3 mol.%) amount of dimers. The parameters of the effective configuration of the monomer molecule were determined. The internuclear distance r (g)(Lu-Br) is 2.553(5) A..., and the effective bond angle a (g)(Br-Lu-Br) is 115.3(10)A degrees. The temperature-averaged r (g) parameters were calculated by the B3LYP method using the potential functions obtained by scanning the PES along the vibration coordinates and compared with similar experimental values. It was shown that the geometrical model of the LuBr3 molecule of D (3h) symmetry was consistent with the experimental data. The dependence of the r (g) parameters of the LuBr3 molecule on the vapor temperature was studied theoretically.