[en] With 94-95% yield the adducts of Ln tris-pivaloyltriofluoroacetonates with crown-ethers of the composition Ln(PTA)₃x18-crown-6 (Ln=La, Nd, Tb, Er, Lu) and Ln(PTA)₃ x dibenzo-18-crown-6(Ln=Nd, Tb, Er) are synthesized. The compounds obtained are studied by the methods of element analysis, UV and IR spectroscopy, ESR and mass spectroscopy. On the basis of physico-chemical properties and studied spectra the conclusion has been drawn that the interaction of Ln tris-β-diketonates with crown-ethers proceeds along the way of substitution of crown ether in lanthanide coordination sphere for water