Composition of overheated vapors and molecular structure of monomeric tris-hexafluoroacetylacetonates of lanthanum, neodymium and samarium

Molecular structure of lanthanum, neodymium and samarium tris-hexafluoroacetylacetonates has been studied by means of simultaneous gas electron diffraction and mass-spectrometric experiment and quantum-chemical calculations. The coordination polyhedron LnO6 was confirmed to be a distorted antiprism of D3-symmetry, and the experimental lanthanide contraction for hfa-complexes within La–Lu series was found to be 0.198(18) Å. Molecular species of La(hfa)3, Nd(hfa)3 and Sm(hfa)3 present in vapor at various degrees of overheating have been identified.