Mixed ligand acetate, propionate, and pivalate complexes of rare earth metals with monoethanolamine: A new approach to the synthesis, composition, structure, and use for the preparation of oxide materials

Abstract

Compositions of mixed ligand acetate, propionate, and pivalate complexes of rare earth metals of the cerium and yttrium groups with monoethanolamine are predetermined by the synthesis conditions and the nature of the carboxylate ligand and rare earth metal ion. Solid mixed ligand complexes [Ln(Piv)₅(MEAH)][MEAH] and [Ln(Piv)₃(MEA)], homoligand complexes [Ln(Piv)₃] (HPiv is 2,2-dimethylpropionic (pivalic) acid), and gel-like hydroxo complexes [Ln(Carb)_3–x–y(NO₃)_x-(OH)_y(MEA)_w(H₂O)_z] (HCarb is acetic (HAc) or propionic (HProp) acid) are isolated using original synthesis procedures involving ion pairs [MEAH]⁺[Carb]^– (MEA is monoethanolamine). The compounds are studied by IR spectroscopy, ¹H NMR spectroscopy, elemental and thermal analyses, and mass spectrometry. Specific features for the complex formation of rare earth metal pivalates with MEA are additionally studied using quantum-chemical simulation.