Self-assembly of heteroleptic tetranuclear carboxylate complexes of yttrium and lanthanides during hydrolysis and oxidation of rare earth homoleptic carboxylates

Abstract

Novel heteroleptic carboxylate complexes bearing hydroxide or peroxide ligands were obtained by hydrolysis [Y4(Ph2CHCOO)10(OH)2(THF)2] (1) or oxidation [Ln4(Ph3CCOO)8(O2)2(THF)4(H2O)2] Ln=Nd (4), Eu (5), and [Nd4(Ph3CCOO)8(O2)(O)(THF)4] (4a). Crystal structure of 1, 4, 4a and 5 were determined by single-crystal X-ray diffraction. The molecular structures of all complexes obtained demonstrate planar framework consisting of four lanthanide or yttrium cations. In the 4a, the rather rare μ3-κ1:κ1:κ1 type of coordination of peroxide for lanthanide complexes was found. Synthesis of these compounds shows the possibility of self-association of rare earth carboxylates under the action of moisture and oxygen.