Abstract: Crystal of gadolinium trifluoracetate[Gd(CF₃COO)3·3H₂O]₂ prepared at room temperature is monoclinic with space group P2₁/c. Its lattice parameters: a= 9.192 (3), b=18.890(1), c=9.785(3)Å; β=113.84(2). The structure was refined to R=0.0422. The results show that every two Gd²⁺ ions are linked in pairs through four O-C-O bridges of CF₃COO groups, forming a complex molecule. The Gd³⁺ is eight-coordinated (3H₂O and 5 CF₃COO). There are two dimers in every cell lattice, viz Z=2. The Gd—O distances range from 2.35 to 2.47 Å. Analysis of spectral properties of [Eu_0.1Gd_0.9(CF₃COO)₃·3H₂O]₂ shows that Eu³⁺(or Gd³⁺) ions occupy two crystallographic sites, viz C₂(or C_s) and C₂h.

Key words: Gadolinium, Trifluoroacetate, Crystal structure