Interaction Features of Cerium (III) and Europium (III) Acetate and Pivalate with Monoethanolamine

The composition of mixed-ligand complexes of cerium (III) and europium (III) acetates and pivalates with monoethanolamine (MEA) depends on the synthesis conditions and the nature of carboxylate ligand. We prepared solid complexes [Ln(Piv)(3)(MEA)(x)], where Ln = Ce, Eu; HPiv-2,2-dimethylpropionic (pivalic) acid; x = 1, 1.5, and gel-like hydroxocomplexes [Ln(Carb)(n-x-y),(NO3)(x)(OH)(y)(MEA)(w)(H2O)(z)], where Ln = Ce, n = 4; Ln = Eu, n = 3; HCarb is acetic acid (HAcet) or HPiv. The values of the coefficients x, y, w, and z depend on the synthesis conditions and heat treatment. Prepared compounds were characterized by IR and H-1 NMR spectroscopies, elemental and thermal analyses, and MALDI-MS. The ESI-MS method was used to characterize the processes occurring in the solutions.