Di- and triphenylacetate complexes of yttrium and europium

Abstract

The significant variety in the crystal structures of rare-earth carboxylate complexes is due to both the large coordination numbers of the rare-earth cations and the ability of the carboxylate anions to form several types of bridges between rare-earth metal atoms. Therefore, these complexes are represented by mono-, di- and polynuclear complexes, and by coordination polymers. The interaction of LnCl3(thf)x(Ln = Eu or Y; thf is tetrahydrofuran) with sodium or diethylammonium diphenylacetate in methanol followed by recrystallization from a DME/THF/hexane solvent mixture (DME is 1,2-dimethoxyethane) leads to crystals of the non-isomorphic dinuclear complexes tetrakis(μ-2,2-diphenylacetato)-κ4O:O′;κ3O,O′:O′;κ3O:O,O′-bis[(1,2-dimethoxyethane-κ2O,O′)(2,2-diphenylacetato-κ2O,O′)europium(III)], [Eu(C14H11O2)6(C4H10O2)2], (I), and tetrakis(μ-2,2-diphenylacetato)-κ4O:O′;κ3O,O′:O′;κ3O:O,O′-bis[(1,2-dimethoxyethane-κ2O,O′)(2,2-diphenylacetato-κ2O,O′)yttrium(III)], [Y(C14H11O2)6(C4H10O2)2], (II), possessing monoclinic (P21/c) symmetry. The [Ln(Ph2CHCOO)3(dme)]2molecule (Ln = Eu or Y) lies on an inversion centre and exhibits three different coordination modes of the diphenylacetate ligands, namely bidentate κ2O,O′-terminal, bidentate μ2-κ1O:κ1O′-bridging and tridentate μ2-κ1O:κ2O,O′-semibridging. The terminal and bridging ligands in (I) are disordered over two positions, with an occupancy ratio of 0.806 (2):0.194 (2). The interaction of EuCl3(thf)2with Na[Ph3CCOO] in methanol followed by crystallization from hot methanol produces crystals of tetrakis(methanol-κO)tris(2,2,2-triphenylacetato)-κ4O:O′;κO-europium(III) methanol disolvate, [Eu(C19H15O2)3(CH3OH)4]·2CH3OH, (III)·2MeOH, with triclinic (P\overline{1}) symmetry. The molecule of (III) contains twoO,O′-bidentate and oneO-monodentate terminal triphenylacetate ligand. (III)·2MeOH possesses one intramolecular and four intermolecular hydrogen bonds, forming a [(III)·2MeOH]2dimer with two bridging methanol molecules.