ic010745l_si_001.cif (121.71 kB)

Synthesis, Characterization, and Properties of Three Europium 2-Propoxides:  [Eu4(OPri)10(HOPri)3]*2HOPri, Eu5O(OPri)13, and EuAl3(OPri)12

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posted on 14.05.2002, 00:00 by G. Westin, M. Moustiakimov, M. Kritikos
The reaction of Eu metal with HOPri/toluene solutions yielded the mixed Eu2+/Eu3+ alkoxide [Eu4(OPri)10(HOPri)3]·2HOPri (1), in contrast to the other lanthanide metals, which exclusively yield trivalent lanthanide ions in the alkoxides formed. Metathesis between EuCl3 and 3KOPri and stoichiometric hydrolysis yielded the square-pyramidal Eu5O(OPri)13 (2), and metathesis with EuCl3 and 3KAl(OPri)4 gave EuAl3(OPri)12 (3). The structures of these compounds were determined by single-crystal X-ray diffraction. IR spectroscopic studies showed that the solid-state molecular structure of the three alkoxides remained close to intact in solution. Further characterizations were made with UV−vis spectroscopy, differential scanning calorimetry, and solubility studies. It was also found that 1 can be converted to 2 by oxidation with dioxygen, but 2 was not reduced by Eu metal to 1. The reactions of 2 and 1 with Al4(OPri)12 in toluene/HOPri solvent were studied by IR and UV−vis spectroscopy; 2 reacted completely to form 3 in 2 h at 75 °C, while 1 reacted to yield 3 and other unidentified Eu2+ containing product(s) in the same time.