Molecular structure of tris(dipivaloylmethanato)lutetium(iii) studied by gas electron diffraction and ab initio and DFT calculations

Abstract

Combined gas electron diffraction/mass spectrometry (GED/MS) was used to determine the molecular structure of tris(dipivaloylmethanato)lutetium(III), Lu(dpm)₃ (dpm = 2,2,6,6-tetramethyl-heptane-3,5-dionato). Up to about 520–570 K the vapour consisted only of molecules Lu(dpm)₃. The experimental data recorded at 408(5) K indicate that the molecules have D₃ symmetry. The bond distances (r_h1) in the chelate ring are Lu–O 2.197(6) Å, C–O 1.270(4) Å and C–C 1.390(6) Å. Theoretical computations at the HF and DFT levels with basis sets up to 6-311G* afford structures similar to those found experimentally, with a distorted LuO₆ antiprism.